Military Preservation Guide

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HQMC

30 Aug 00

E R R A T U M

to

MCO P4030.23F

GUIDE FOR BASIC MILITARY PRESERVATION

AND PACKING

1. Change "MCO P4030.23E" to read: "MCO P4030.23F" of 1 Dec 1999.

PCN 10204040080

*U.S. GOVERNMENT PRINTING OFFICE:2000-461-735/20033


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DEPARTMENT OF THE ARMY TRAINING CIRCULAR TC 38-3MARINE CORPS ORDER MCO P4030.23EDEPARTMENT OF THE NAVY PUBLICATION NAVSUP PUB 442DEPARTMENT OF THE AIR FORCE PAMPHLET AFPAM(I) 24-205DEFENSE LOGISTICS AGENCY INSTRUCTION DLAI 4145.1

_________________________________________________________________________________________________

GUIDE FOR BASIC

MILITARY PRESERVATION

AND PACKING

DISTRIBUTION RESTRICTION: Approved for public release; distribution is unlimited.

DEPARTMENTS OF THE ARMY, THE NAVY, THE AIR FORCE,AND THE DEFENSE LOGISTICS AGENCY


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This publication is available on the

General Dennis J. Reimer Training

And Doctrine Digital Library at

www.adtdl.army.mil


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i

*TC 38-3

MCO P4030.23E

NAVSUP PUB 442

AFPAM(I) 24-205

DLAI 4145.11 December 1999

DEP ARTMENTS OF THE ARMY,

NAVY, AND AIR F ORC E, AND TH E

DEFE NSE LOGI STI CS AGENCY

GUIDE F OR BASIC MILITARY PRE SERVATION AND PACKING

CH AP TE R P AGE

CHAPTE R 1 - INTRODUCTIONGENE RAL ..................................................................................................................... 1-1

CONTACT, F ORMAT, AND US E ................................................................................ 1-1

CHAPTE R 2 MILITARY PR ESE RVATIONINTRODU CTION TO PRESE RVATION .................................................................... 2-1

CORROSION CONTROL ............................................................................................. 2-9

CLE ANING AND DRYING .......................................................................................... 2-13

ELECTROS TATIC DISCHARGE CON TROL ............................................................ 2-36

PRES ERVATIVES ........................................................................................................ 2-41

PRESRE VATION MATERIALS AND HE AT SEALING EQUIP MENT .................. 2-57CUS HI ONI NG, BLOCKIN G AND BRACIN G............................................................ 2-72

METHO DS OF PRE SE RVATION ............................................................................... 2-91

MISCE LLANEOU S PACKAGING REQU IRE MEN TS.............................................. 2-109

CHAPTE R 3 MILITARY P ACKING

INTRODU CTION TO MILI TARY PACKI NG ............................................................ 3-1

FIBE RBOARD SH IPI NG BOXES (ASTM D 1974/ASTM D 51 18)............................ 3-9

TRIPLE -WALL CORRUGATED F IBERBOARD BOXES (ASTM D 5168 ................ 3-30

WOODE N BOXES ........................................................................................................ 3-39

CRATES ......................................................................................................................... 3-57

MISCE LLANE OUS CONTAINE RS ............................................................................ 3-78

CHAPTER 4 - P ACKI NG PROCE DURES AND OPE RATI ONSWEATH ERPROOF ING TH E PACK ........................................................................... 4-1

CARGO UN ITIZATION................................................................................................ 4-10

MARKING AND LABELING....................................................................................... 4-28

HAZARDOUS MATERI ALS ........................................................................................ 4-61

SMALL P ARCEL SH IP MEN T..................................................................................... 4-68

* This training circular supersedes DA PAM 740-1/NAVSUP PUB 442/AFP 71-14/MCO P4030.23D/

DLAH 4145.1, Instructional Guide for Basic Military Preservation and Packing, 29 June 1990.DLAH 4145.1, Instructional Guide for Basic Military Preservation and Packing, 29 June 1990.


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TC 38-3/MCO P4030.23E/NAVSUP PUB 442/AFPAM(I) 24-205/DLAI 4145.1

1-1

Chapter 1

Introduction

GENERAL

P U R P O S E

This circular provides a series of lessons for use in training personnel in

preser vation and packing opera tions. These lessons ar e published for use as an

official document in the training of military and civilian personnel from all

segments of the Depar tmen t of Defense (DOD) and supporting a gencies. It

contains information based on specifications, standards, MIL-STD-2073-1C,

Stan dar d Practice for Military Packaging, an d other pert inent documen ts. In

keeping with the established preservation and packing policy, emphasis is

placed on efficiency and economy in all preservation and packing operations.

The use of this set of lessons will eliminate the need for the preparation of

similar guides at separ at e insta llations

CONTE NT, FOR MAT, AND USE

GENERAL

These lessons have been prepared for use in training operating personnel

working on preservation and packing lines at installations thr oughout DOD. In

the pr epara tion of these lessons, the dominan t consideration has been to make

them as flexible as possible so tha t th ey may meet the r equirement s of a var iety

of tra ining situat ions. The technical dat a and specifications r eferenced in t his

pamph let represent the cur rent pr eservation an d packing practices. The titles

of th e documen ts referenced in th e various lessons h erein ar e listed in a ppendix

A located immediately after chapt er 4.

F ORMAT AND C ONTENT

L e s so n C o n t e n t

This circular consist s of lessons on t he following:

Intr oduction to military pr eservation.

Corrosion cont rol.

Cleaning and drying.

Electrostatic discharge control.

Preservatives.

Preservation materials and heat sealing equipment.

Cushioning, blocking, and bracing. Methods of preservation.

Miscellan eous packaging requ irement s.

Intr oduction to milita ry pa cking.

Fiberboard shipping boxes.

Triple-wall corrugated fiberboard boxes.

Wooden boxes.

Crates.

Miscellaneous containers.

Weather proofing th e pack.


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1-2

Cargo un itization.

Marking an d labeling.

Hazardous mat erials.

Small parcel shipment .

KE E P I N G T H E TRAINING P RACTICAL

Ti m e All o t m en t s

In accordance with lesson objectives, methods of instruction, and time

allotments established for each lesson, it is suggested that all training be made

as pra ctical as possible. This will assur e an impr ovement in t he qua lity of

workm ansh ip. The allotmen t of approximat ely 25 percent of the t raining time

to conference instruction and 65 percent to demonstrations and practical

exercises should be followed as closely as possible. Actu al pres erva tion an d

packing working ar eas should be used.

Objec t ive

The what, how, when and why of each major preservation and packaging

principle has been em pha sized. These lessons will serve to keep instru ction

focused on the basic requirements of militar y preservat ion and packing.

LES S ON ARRANGEMENT AND SUGGES TED T IME ALLOTMENTS

The following lesson arrangement may be used as a guide in presenting the

informa tion in th is pamphlet:

Chapt er 1 - Introduction

Purpose

Content, Format, a nd Use

Chapt er 2 - Military P reservat ion

Intr oduction to Militar y Pr eservation, Conference (1 hour)

Corrosion Cont rol, Conferen ce (1 hour )

Cleaning and Drying, Conference (1 hour), Practical Exercise (1hour)

Electrostatic Discharge Control, Conference (1 hour)

Preservatives, Conference (2 hours), Practical Exercise (1 hour)

Preser vation Materials and H eat Sealing Equipmen t, Conference (1

hour), Practical Exercise (1 hour)

Cush ioning, Blocking, an d Bra cing, Conference (2 hour s), Pr actical

Exercise (1 hour)

Methods of Preservation, Conference (3 hours), Practical Exercise

( 1 hour)

Miscellaneous Packaging Requirements, Conference (2 hours)

Chapt er 3 - Militar y Packing Introduction to Military Packing, Conference (1 hour)

Fiberboard Shipping Boxes, Conference (1.5 hours), Practical

Exer cise (1.5 hour s)

Triple-wall Corrugated Fiberboard Boxes, Conference (1 hour),

Practical Exercise (1 hour)

Wooden Boxes, Conferen ce (2 hour s), Pra ctical E xercise (2 hour s)

Crates, Conference (2 hours), Practical Exercise (2 hours)

Miscellaneous Containers, Conference (1 hour)


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1-3

Chapt er 4 - Packing Procedures a nd Opera tions

Weatherproofing the Pack, Conference (1 hour), Practical Exercise

(1 hour )

Cargo Unitization, Conference (2 hours), Practical Exercise (1 hour)

Marking and Labeling, Conference 2 hours), Practical Exercise (1

hour)

Hazar dous Mater ials, Conference (2 hours)

Small Pa rcel Shipment, Conference (1 hour)

C h a n g e s a n d R e v i si o n s

Revisions or changes t o this pu blication, du e to m ajor changes in preservat ion

packing policy, doctrine, revision of specifications, and other official

preservation/packing instru ctions will be made on a continuing basis a s th e need

arises.

Users of this training circular are encouraged to submit recommended changes

or comments t o improve th e publication. Commen ts should be keyed to th e

specific page, and line of th e text in which th e cha nge is recommen ded. Reasons

should be provided for each comment to ensure understanding and completeevalua tion. Commen ts should be forwa rded to Dean , School of Milita ry

Pa ckaging Techn ology, ATTN: ATSL-MPT, 360 Lan yar d Road, Aberde en

Pr oving Gr ound , MD 21005-5003.


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2-1

CHAPTER 2

Military Preservation

INTRODUCTION TO MILITARY PR ESE RVATION

NE E D F OR T RAINING/P RESERVATION

N e e d fo r P r e s e r v a t i o n T r a i n i n g

An und erst an ding of preser vation is needed at a ll depar tm ent levels, especially

at th e operat iona l level. Personn el at th e operat iona l level have th e most

physical contact with preservat ion. They must kn ow wha t they ar e doing and

fully underst an d th e need for doing it.

Def i c ien ci es

Deficiencies in pr eservation are caused by man y different factors. Failure t o

employ proper preservation instr uctions results in deficiencies. Thesepackaging deficiencies are reported on SF 364, Supply Discrepancy Report

(SDR).

T r a i n i n g

To correct deficiencies, per sonnel mu st be tr ain ed in th e proper pr ocedu res for

preservat ion of militar y su pplies.

Wh a t i s P r e s e r v a t i o n ?

Preservation is the application or use of protective measures to include cleaning,

drying, preserva tive application, pr otective wra pping a nd/or cushioning, placing

the item into a conta iner, an d complete identification m ark ings. The basic steps

involved in pr eservation ar e illustr ated in figure 2-1.

C l e a n i n g

All substa nces (contam inan ts) which would cau se or promote corr osion mu st be

removed.

Dr yi n g

Must be a ccomplished immediat ely after clean ing to remove cleanin g solutions

or any other r emaining moisture.

Preservat i ve Appl ica t ion

A preservat ive is used to keep items in a u seful condition by pr oviding a bar rier

to keep out moisture, oxygen, and other causes of corrosion.

Wr ap a nd /or Cus h i on

Appropriate wrapping is used to retain the preservative on the item.

Cush ioning is used to protect the item aga inst physical an d mechanical damage

and to protect barr ier m aterials and containers a gainst puncture.

P l a c i n g i n C on t a i n e r

Inter ior conta iners are u sed to increase the assur ance tha t th e cleaned, dried,

an d pr eserved item will be in a ser viceable condition a fter shipm ent or storage.

Ma r k in g

Markings mu st be applied to identify the contents.


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2-2

Figure 2-1. Basic steps in Military Pr eservation.

H a z a r d s t o Mi li t a r y S u p p li e s a n d E q u i p m e n t

Ge ne r a l

We must pr otect our militar y supplies and equipmen t from both climatic and

mechanical hazards from procur ement t o end u se.

C l im a t i c h a z a r d s

Thirty minutes does not seem like a long time, yet 30 minutes of improper

storage could da mage some items wh en t hey ar e exposed to a var iety of clima tic

conditions such as those shown in figure 2-2.

Da m a ge by w a t er

Water dam age is the largest source of dama ge to militar y items. Water ma y

cau se dama ge in two ways:

Water combined with oxygen will cau se rust on iron an d steel. It will

cause corr osion on other k inds of met als. Corrosion ma y be caused by

water in one of thr ee forms. It ma y be liquid, such as ra in or snow. It

ma y be in th e form of mist or spr ay, such as fog or ocean sp ra y. Ocean

spra y conta ins salt a nd is especially corrosive. It ma y be in t he form of

invisible vapors. This form of water is nearly everywhere and is ha rd

to control since it can not be seen. Water vapor can penetr at e into th e

smallest crevice and cause dama ge to even th e most intricate item.

Water can cause da ma ge by aiding in t he growth of mold, mildew, fungi,

and rot.


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2-3

Figure 2-2. Climat ic Hazar ds.

D a m a g e b y D u s t a n d D i r t

Dust an d dirt can dam age small bearings, gears, and small moving part s. A

wristwatch, for exam ple, would be r uined if dust an d dirt were a llowed inside

it. Dust a nd dirt m ay conta in chemical ingredients which may pit or corr ode

polished or critical sur faces. Dust from factory wastes m ay be highly corr osive.

Dust and dirt may scratch precision lenses on binoculars, cameras, and fire-

control items. It ma y also scratch highly polished metal sur faces. Dust an d dirt

may also contamina te ster ile medical sup plies, such as medicines, bandages, an d

instruments.

D a m a g e b y D ir e c t S u n l ig h t

Direct su nlight will cau se some fabrics to fade when exposed an d m ay cause a

breakdown an d cha nge in certa in chemicals. Films, rubber, and sensitive paper

will be ruined by exposur e to sunlight or it may cause th e rupt ur e of cont ainer s

if th ey are filled to capa city with volat ile liquids. Direct sun light or heat m ay

cause expansion of metals, which could result in the decalibration of highly

precise instruments.


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2-4

Mec h a n i ca l h a z a r d s

The kind of hazar ds pictu red in figure 2-3 cau se severe dam age to our supp lies

an d equipment a nd is th e result of improper han dling, stacking, or th e improper

use of equipment, e.g., ships, cranes, slings, nets, etc.

Dam age by I n s ec t s , Ve r m i n , Roden t s , an d Bi r ds

Bird droppings and rodent excreta ma y soil items, par ticularly fabrics. Moth smay eat fabrics, especially wool. Insects an d rodents will eat perisha bles an d

food st uffs.

Spec i a l Cons i de r a t i on Neces s a r y i n S t o r age o f L i qu i ds

Liquids may leak or evaporate. This could cau se a safety haza rd if the liquid is

flamma ble, corrosive, or toxic. Heat can cause th e rupt ure of containers if

sufficient r oom for expan sion is not allowed. Man y liquids mu st be protected

from freezing or p revented from setting.

S t a t i c e l e ct r i c i t y

Some electronic componen ts a re sen sitive to electrosta tic discharge a nd mu st be

protected dur ing, han dling, stora ge, and sh ipment from this hazard.

Figure 2-3. Mechan ical Hazards.


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2-5

P o l icy fo r t h e Pa ckag i ng o f M a t e r i e l

Every company or business in operation today operates under some kind of

corpora te instr uctions, bylaws, policies, etc. The Depar tm ent of Defense also

ha s policies which mu st be followed. These policies are in th e form of

instru ctions a nd a re implemented by the m ilitary services and other components

of th e govern men t. The implemen tin g docum ent is AR 700-15/ NAVSUP INST

4030.28D/AFJMAN 24-206/MCO 4030.33D/DLAd 4145.7, Packaging of Materiel.

P o l ic y s t a t e m e n t

All defense materiel shall be afforded the degree of protection required to

prevent deterioration and damage dur ing shipment, handling and storage.

M il it a r y P a c k a g i n g Ve r s u s C o m m e r c i a l P a c k a g i n g

There is a clear distinction between the guidelines set forth for the military

packa ging concept an d those set forth for comm ercial packaging. The difference

between th e two is as follows:

Military packaging requires the use of specification materials;

interpretation of preservation/packing instructions; MIL-STD-129,

Militar y Markin g; an d th e preser vation met hods of MIL-STD-2073-1C,Stan dard Pra ctice for Militar y Packaging. Militar y packaging should be

used for items expected to enter t he military distribution system. The

military distribution system is the process by which materiel, not

intended for immediate u se, is stored a nd/or m oved within or between

DOD facilities. It ma y also cover items int end ed for delivery-at-sea,

items delivered durin g wartime, or items r equiring reusa ble containers .

Commer cial pa ckaging per mits use of nonspecification m ater ials, and

ASTM D 3951, Standard Practice for Commercial Packaging, provides

sta nd ar d comm ercial guidelines. Applicat ion of pres erva tion/packing

techniques is at the discretion of the contra ctor or th e activity. Items

not going into stock, items inten ded for immediat e us e (ex. AOG), items

for not mission-capable supply (NMCS), items intended for depot

operational consumption, small parcel shipments (CONUS, not-for-

stock) and direct vendor deliveries (CONUS) shall be packaged in

accordance with st an dar d commer cial pr actice a s defined in ASTM D

3951.

Leve l s o f Mi li t a r y P r o t ec t i on

A means of specifying the level of packing that a given item requires to assure

tha t it is not degraded dur ing shipment and st orage. Figure 2-4 shows the levels

of pr otection for milita ry packing. These levels are ident ified as level A and

level B. Level A provides maximu m protection, and level B provides moderat e

protection.

Levels of Pa cking. Level A. Pr otection t o meet the most severe worldwide shipment,

han dling, an d storage conditions. A level A pack mu st, in ta ndem

with the applied preservation, be capable of protecting materiel

from the effects of direct exposure to extremes of climate, terrain,

and operat iona l and tran sportat ion environment s. Exam ples of

situations which indicate a need for use of a level A pack are:

mobilization, strategic and theater deployment and employment,

open storage, and deck loadin g. Exa mples of cont ain ers used for

level A packing requirements include, but are not limited to,


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overseas type wood boxes, and plastic and metal reusable

containers.

Level B. Protection to meet moderate worldwide shipment ,

han dling, an d storage conditions. A level B pack must, in ta ndem

with t he a pplied preservat ion, be capable of protecting ma ter iel not

directly exposed to extremes of climat e terr ain a nd opera tional an d

tra nsporta tion environm ents. Exam ples of situat ions whichindicate a need for use of a level B pack are: securit y assista nce

(e.g., Foreign Military Sales (FMS)) and containerized overseas

shipment s. Exam ples of containers used for level B packing

requirements include, but are not limited to, domestic wood crates,

weather-resistant fiberboard containers, fastpack containers,

weather-resistant fiber drums, and weather-resistant paper and

multi-wall shipping sacks.

Figure 2-5 depicts progressive item protection based on levels of

protection.

Figur e 2-4. Levels of Pr otection.


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Proper supervision. The quality an d quan tity of work are directly

related to the kind of supervision given.

J ob requ iremen ts. It is importa nt t o show techn ical competen ce on th e

job and to u nder st and our in dividu al job ass ign men t and it s im pa ct on

the overall mission.

Plann ing. Ea ch operat ion in preservat ion an d packing should be well

plann ed in efficient u se of personnel an d m achines.

C h e c k u p

What a re th e basic steps of militar y preservation an d packing?

What are the two levels of militar y protection?

What level of pr otection is requir ed for th e protection of ma ter iel against

the most severe conditions known or anticipated to be encountered

during shipment, handling, and storage?

List some importa nt factors tha t can influence economy in pa cking.

Why is mar king an importa nt st ep of preservat ion?

Why is it importan t t o dry an item immediat ely after cleaning?

What is the r eason for u sing cush ioning inside a pa ckage?

Why is it importan t to tr ain personn el at th e operationa l level?


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2-9

CORROSION CONTROL

C ORROS ION

Corrosion is th e breakdown of meta ls when th ey are in cont act with water an d

air . Rust is often used to describe an y type of corr osion. It is actua lly a ter m

which describes corrosion on iron or relat ed metals. Ferr ous metals are an y

meta ls which conta in or are ma de from iron.

C ORROS ION OF F ERROUS AND NO N F E R R O U S METALS

Corrosion on iron an d steel (ferrous meta ls) is termed ru st. It is usua lly red in

color an d form s a ru sty film which holds moistur e and oxygen like a blott er. It

speeds up furt her corrosion by acting as a reservoir wh ich feeds moistur e an d

oxygen to unr usted area s, as shown in figur e 2-6.

Figure 2-7 illustr at es corr osion on n onferr ous meta ls such as zinc and cadmiu m

which is often white or gray in color. The ter ms "white ru st an d oxidat ion" are

often ap plied to th is type of corrosion.

Figur e 2-6. Corrosion of Fer rous Metals.

Figur e 2-7. Corrosion of Nonferr ous Metals.


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2-10

WHAT IS KNOWN ABOUT CORROS ION --BASIS FOR C ONTROL

For t he pu rpose of un derst an ding corr osion cont rol, corrosion will be explained

by compa rin g it to the operat ion of a stora ge batter y. In order for corrosion to

tak e place, cert ain elements ha ve to be present. They are a metallic par t, water,

and oxygen. In order for a bat tery to produce a charge, certa in element s must

also be present, as depicted in figure 2-8. They are positive and negat ive

met allic electr odes, and a n electrolyte. The positive electrode is constr ucted ofone kind of met al, and t he nega tive electr ode of a differen t kind of met al. This

potential difference (a positive and a n egative) mu st be pr esent for an electric

curr ent t o be produced. The electr olyte in the storage batt ery would be similar

to the water and oxygen in the corrosion process, and the battery's metal

electrodes ar e similar to th e meta l which corrodes.

Figure 2-9 shows th at when an item is made of two or more dissimilar m etals,

accelera ted corr osion will ta ke place. When only one kin d of met al exists,

normal corrosion will take place. With out th e th ree elements, shown in figure

2-9 th ere would be no electr ic curren t from a ba tt ery an d no corr osive action on

the met allic item. In ma ny cases, batter ies are packed in a "dry" stat e so th at

the bat tery will not generat e an electric curr ent. Similar ly, in corrosion,

basically no corrosive action will ta ke place un less moistu re is pr esent . Themost obvious thing to do to prevent corrosion would be to eliminate moisture.

This could be done by applying a wa ter proof or wat er-vaporproof bar rier t o the

item. Even if the par t is not ma de of two different meta ls (as t he electrodes in

the battery), there is enough potential difference between areas within one

meta l to cause corr osion. In order for t hese two area s to react, they ha ve to be

conn ected some way. This is done by the electrolyte (wat er).

Figure 2-8. Compar ing Corrosion with a St orage Battery.


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Figure 2-9. Corrosion Elements.

C ORROS ION C ONTROLS IN P RESERVATION

Simply stat ed, preser vation cont rols corrosion by cont rolling wha t would am ount

to the battery water in t he "corrosion battery." Cont amina nt s, which wouldmak e any moisture present a bett er electrolyte, must be removed. Moisture,

which would tak e conta minan ts int o solution t o make an electrolyte, must be

kept from th e sur face of th e part by preservat ive application and/or sealed unit

packages. Oxygen is somet imes contr olled by adding a su bstan ce (antioxidan t)

to the preservative. This substan ce removes the oxygen.

Corrosion controls are included in the three basic operations which make up

un it pr otection (cleaning, preservat ive application, an d u nit packaging).

Cleaning is the first operat ion in un it protection. Details of the cleaning

processes will be covered in a noth er lesson. The ma in rea son for cleanin g is to

remove contamina nt s from t he item t o prevent a bat tery-type action from taking

place. Immediat ely after cleaning, the item mu st be thoroughly rinsed toremove the residue of th e cleaning agent. Heavy empha sis is placed on

fingerprint removal when cleaning items which ha ve a h ighly polished critical

sur face. The r eason for t his is becau se oils from fingers ar e salty-acid cont am i-

na nts which act as an extremely effective electrolyte wh en combined with water.

Drying, although accomplished by separately identified procedures, becomes

par t of the overall cleaning opera tion.


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Pr eservat ive application is th e second opera tion in unit pr otection. Deta ils will

be covered in another lesson. The main r eason for a temporar y preservative

coating is to insulat e the meta l sur face from moistu re and conta minan ts. To

fight corrosion, we must apply a good, uniform, continuous coating of

preservat ive to the item. The heavier preservat ives may not be used on more

complex items because of th eir difficulty in removal. A lighter pr eserva tive may

be used within a sealed barr ier provided in th e meth od of unit pr otection.

Completing the method of unit protection is the third operation in unit

protection. Deta ils will be covered in anoth er lesson. The following genera l

observations r elate t he preservat ion meth ods to corr osion contr ol.

Cleaning, preservative application, and unit protection make up the techniques

required to prevent corrosion. These thr ee operat ions sh ould be carried out in

a contin uous cycle withou t layover between opera tions. It is especially

important that parts not be held over between cleaning and preservative

application.

C h e c k u p

In general, it can be stated that most corrosion takes place in thepresence of what thr ee things?

How would a zinc plated steel bolt appear as it becomes progressively

corroded?

Why can the operation of a storage battery and formation of corrosion

be compar ed?

What is the preservat ion appr oach to corr osion contr ol?

Preser vation operations sh ould be perform ed in one cont inuous cycle.

Fr om a corrosion cont rol stan dpoint , where is the most da ma ging place

to have a time break in operat ions?


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CLE ANING AND DR YING

C LEANING R EQUIREMENTS

The cleaning requirements differ for military preservation from those for

commercial packaging and are defined below.

C o m m e r c i a l P a c k a g i n gThe cleaning r equirem ent s for comm ercial packaging a re specified in ASTM D

3951. Item s will be free from dirt an d conta mina nt s which would contribut e to

deterioration of the item or which would require special cleaning by the

cust omer prior to use. Coatings an d preservatives applied to the item for

protection a re n ot considered conta minan ts.

TYP ES OF CONTAMINANTS

Before we discuss t he clean ing and drying operations, we will learn about t he

different types of contamina nts tha t m ust be removed a s shown in figur e 2-10.

A contam inant is any ma tter on the item, other t han the ma terial it was ma de

from. Dirt is often called a cont amin an t. In gener al, we are concerned with fourtypes of contam inant s.

Oil Soluble

This group includes all oily or grea sy substa nces. These should be the first

contam inan ts rem oved in an y cleaning operation.

Wat e r So lub l e

This group includes fingerprint s, perspirat ion, soldering a nd welding fluxes, and

mar king inks. These contam inan ts are not removed with ordina ry solvents or

cleaners. They are rem oved with a fingerpr int rem oving compoun d.

Figure 2-10. Types of Conta minan ts.


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2-14

I n s o lu b l e L o o s e ly A d h e r i n g C o n t a m i n a n t s

Loosely adhering contaminants may be solid dirt particles, abrasive grains,

meta l chips a nd filings which can be removed with wat er or solvents.

I n s o lu b l e T i g h t ly A d h e r i n g C o n t a m i n a n t s

Tightly adhering contaminants may be mill and heat scale, carbon deposits,

rust, and other corrosion products which must be removed by mechanicalclean ing pr ocesses.

Each of these groups of contam inant s mu st be removed by different mean s. If

contaminants from more than one group are on the item, the oils and greases

must be removed first, then the insoluble contam inan ts, followed by th e wat er

soluble contam inan ts.

B ASIC CLEANING R EQUIREMENTS

Good workm an ship is necessar y to do a good job in clean ing. The following

requiremen ts illustra ted in figure 2-11, have been esta blished for cleaning:

C le a n i n g M u s t b e T h o r o u g h

All contam inant s mu st be removed before the a pplication of a pr eservative. Anycontam inant left on an item will cause corrosion or deter iora tion.

Figur e 2-11. Basic Requirem ent s for Clean ing.


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2-15

P r o c e ss Mu s t N o t I n j u r e t h e I t e m

Select a process th at will not cause dama ge to an item. You wouldn't select a

harsh solvent for leather goods because of its damaging effect.

Di s as s em bl y Sha l l be L i m i t ed

Limit the disassembly to a point wher e reassembly can be easily done without

special tools or sk ills.

F i n g e r p r i n t s Mu s t b e R e m o v e d F r o m C r i t ic a l Su r fa c e s

The acid in our fingerprints is corrosive, and, if not removed from critical

(precision) surfaces, it will etch these surfaces in a short time.

To assu re th orough cleaning of the item, it should pass a cleanliness test. If any

contam inan t is left on the item, th e item must be recleaned.

C LEANING P ROCES S ES SELECTION

The selection of a clean ing pr ocess depen ds u pon th e following factors:

Com pos i t i on o f t he I t em

The composition of th e item limits th e choice of th e clean ing processes. Item smade from a luminum or zinc should n ot be cleaned in h ighly alkaline cleaners

because of th e detrim ent al effect of th e clean er. Nonm eta llic item s of ru bber,

fabric, cork, or oth er organ ic composition sh ould not be cleaned h aph azar dly in

organ ic or water -soluble alkaline cleaner s. If solvent clean ing is app lied to such

items, the solvent exposur e mu st be brief and scru bbing a ction limited wh en

dimensions and u se conditions of the item a re critical. Solvents ar e detriment al

to most rubber and synthet ic rubber ma terials. If meta llic and n onmetallic

mat erials are combined in an assembly, the cleaning process mu st be carefully

considered a nd t he choice of the process governed by th e na tu re of the ma terials

combined in t he assembly.

Sur face F i n i s h o f t he I t em

Some cleaning processes are safe to use on highly finished and precision

surfaces while oth er processes are likely to damage the finish. For insta nce,

alka line cleanin g should not be used on polished alum inum . Acid cleaner s are

used in iron an d steel with extr eme care. Solvent cleaning pr ocesses are usu ally

recommen ded for most critical sur faces of met al items. Sur faces of rough

forgings or cast ings, rough ground or r ough ma chined items, or sur faces having

no finishing after stamping or drawings are cleaned by alkaline cleaning

processes. Item s with porous sur faces, small crevices, or holes are n ot cleaned

with alkaline cleaning processes because the complete removal of all residues

is not possible an d corrosion will resu lt. Solvent clean ing can not be applied

indiscriminately to painted surfaces; however, zinc-coated primers, exterior

paints, lacquers, and en amels ar e usua lly han dled safely in solvent cleaners.

Com pl ex i t y o f t he I t em

Items h aving irregular su rfaces, crevices, undercuts, an d pockets t hat could tr ap

clean ing fluids m ay only be cleaned by br ush ing or wiping when solvent cleaning

is used. Clean complex assemblies before they ar e assembled. Assemblies such

as electric generators, motors, starters, gauges, meters, timing devices, and

other complex units should be cleaned before assembly and kept clean

thereafter.


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2-16

H e a l t h a n d S a fe t y H a z a r d s

All cleaning processes have health and safety hazards that must be recognized.

These cleaning processes must comply with the requirements of the

Occupational Safety and Health Act (OSHA) of 1970, or Executive Order 11612,

as applicable.

Ap p r o v e d C l ea n i n g P r o c e s s esThe selection of a cleaning process is very important; if not selected properly,

more harm than good may result .

C le a n i n g P r o c e s s

Items shall be cleaned and dried by any suitable process which is not injurious

to the item. The meth ods an d mat erials of clean ing may include th e following;

however, th ey ar e n ot limited t o those listed below:

Wire bru shing ma y be used to remove loose scales an d light ru st from

items. Oily or greasy contam inant s must be removed before wire

brush ing. Wire brushes should be made of th e same material as the

meta l being clean ed.

Air va cuu m cleaning should be used on items which can not be cleanedby oth er mecha nical or chemical processes. It can be used on ra dio an d

electronic items to remove dust, lint particles, etc.

Barrel tumbling cleans by the use of both chemical and mechanical

actions on the corroded surface. Chemical cleaners su ch as pickling bat hs.

So lven t C l ean i n g

Solvent cleanin g uses severa l differen t kind s of solvent s. Solvent clean ing is

used whe n th e only conta mina nt is a light gr ease or oil. It will not remove rust

or fingerprints an d oth er water-soluble contam inan ts. Fingerpr int removal is

used on a ll items wit h critical fun ctioning sur faces or items with close tolera nces

to remove fingerprints, perspiration, and other water-soluble contaminants.

Solvent cleaning followed by fingerprint removal is sometimes necessary.

Ma t er i a l s for S ol ven t Cl ea n in g

The ma terials used in solvent cleaning are dry cleaning solvent Type III, paint

thinn er a nd fingerprint remover corr osion pr eventive compoun d.

Dry clean ing solvent (P-D-680), Type III only. This is a wat er-clear

liquid that is neutral to metals and is sometimes known as Stoddard

solvent. It is slightly irrita ting to the skin an d may be mildly

na useating when excessive vapors ar e breathed. It can be used on meta l

surfaces by brushing, wiping, spraying an d immer sion to remove oils

an d light greases. The solvent mu st be used only at room temper atu res.

P-D-680, Types I and II are being phased out as environmentally

ha zardous solvents which must be disposed of as a ha zardous wast e.There a re environment ally compliant solvents th at clean as well as P -D-

680, Types I and II. Approved substitutes tha t are environment ally

compliant solvents at this time include Breakthrough, Electron 296,

Skysol 100, Skysol, an d PF. Do not use water -based enzymes as a

subst itut e for P-D-680 as th ey do not pr ovide corrosion pr otection. For

questions concerning the availability of solvent products, contact the

Defense Supply Center Richmond, 8000 Jefferson Davis Highway,

Richmond VA 23297-5100, or call 1-800-352-2852 and ask for the

En vironm enta l Products cat alog.


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2-17

Note: WARNI NG: Keep solvent away from an y open flame or source of

sparks.

Pa int Thinn er (TT-T-291). This mat erial is supp lied in two grad es and

only gra de I is used for solvent cleaning. It is similar to dry clean ing

solvent (P-D-680) in th at it rem oves oils and light greases, h aving a lowflash point a nd degree of toxicity. Used pain t thin ner m ust be disposed

of as a h azar dous waste.

Fin gerpr int Rem over Corr osion Pr eventive Compound (MIL-C-15074).

This mater ial is a mixture of solvent, soap an d water. It is used to

remove fingerprints, su ppress perspira tion corrosion, a nd temporar ily

protect steel su rfaces.

E qu i p m en t f or S olven t Clea n in g

Metal tanks are required for solvent cleaning, and they usually contain

provisions for spr aying operat ions. The ta nks sh ould be equipped with safety

featur es consisting of a tight fitting lid, a fusible link, a nd a ground conn ection,

as shown in figure 2-12. The rea sons for the safety feat ur es are as follows: if

th e solvent sh ould cat ch fire, the h eat would melt t he fusible link an d allow th etight fitting lid to close and smoth er th e fire, and t he groun d conn ection is used

to car ry off an y stat ic cha rges of electr icity. It is importan t t ha t th e fusible link

always be in an operable condition and that the lid should never be wired or

fasten ed in t he open position.

Figure 2-12. Solvent tan k with safety featu res.


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2-18

Saf e t y P r ecau t i ons fo r So lven t C l ean i n g

Observe th e following:

When n ot in use, covers mu st be k ept closed on all solvent t an ks.

Provide adequate ventilation t o prevent vapor fume build up. Inha ling

solvent vapors ma y cause d izziness, fainting a nd n au sea.

Fire extinguishers must be located in the area , and personnel must betrained in their use.

A fire blanket should be located near by.

Since solvents may cause skin irritations, operators should wear oil

resistant rubber or plastic gloves and work aprons during cleaning

operations as illustra ted in figure 2-13.

So l v e n t Cl e an i n g

Figure 2-14 depicts two tan ks required to clean by immersion. One tan k is used

for cleaning an d th e other for r insing.

Cleaning by immersion. The solvent clean ing immer sion steps are

illustra ted in figure 2-15. These steps include placing items in th e

solvent clean ing ta nk so they r eceive th e most effective wash ing action;agitating the items thoroughly for complete cleaning; using a brush

where necessary t o remove hea vy contamina nts; rem oving clean items

from the tank and allowing them to drain completely; immersing the

items in a second tank (rinse tank) and agitating as necessary; and

removing items from the rinse tank and placing them on a tray to

thoroughly drain.

Cleaning by scrubbing and wiping. When conta minat ed items are too

large for the cleaning tanks, or because it is impractical to clean by

immersion or spra ying, they should be cleaned by scru bbing a nd wiping.

The solvent cleaning by scrubbing and wiping steps are as shown in

figur e 2-16. The steps include soaking clean cloth or bru sh in clean

solvent; masking off areas of the item th at can be da maged by solvent;

applying th e soaked cloth an d/or brush t o the dirty ar ea an d scrubbing

an d wiping as necessary; rinsing off the ar ea with a clean cloth soaked

in clean solvent; an d dra ining and wiping the cleaned ar ea dry.

Cleaning by spraying. When item s are of a simple constr uction, free of

cavities and inden tat ions wher e cleaning solvents can be tr apped, th e

clean ing can be done by spra ying as described in figure 2-17. The steps

involved in solvent cleaning by spraying include loading items in a work

basket an d lowering the basket into a spray tank; turn ing on th e spray

pum p an d directing the n ozzle at items, assu ring complete clean ing of

the item; and removing the basket of items from the spray zone and

allowing it to drain. A rinse is not required if th e spray system is

equipped with filters a llowing th e spra yed solvent to be cleaned.

Perspira tion an d fingerprint r emoval.

Solvent clean ing followed by finger prin t r emoval.


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Figur e 2-13. Solvent sa fety clothing.

Figur e 2-14. Solvent clean ing by immer sion.


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Figure 2-15. Solvent immersion steps.

Figure 2-16. Solvent scrubbing and wiping.


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2-21

Figur e 2-17. Solvent spra y clean ing.

P e r s p i r a t i on a n d F i n g e r p r i n t R e m o va l

Two tan ks are required for cleaning perspiration and fingerprints. One tan k

should conta in fingerprint remover compound (MIL-C-15074) and th e other a

clean ing solvent. This process is used on all item s having critical functioning

sur faces or close toleran ces. Before th is process is used , the item mu st first be

cleaned of all other conta minan ts. Steps involved in the perspirat ion an d

fingerprint removal process ar e illustr at ed in figur e 2-18 an d include immer sing

item(s) in per spiration an d fingerprint remover compoun d an d agitatin g while

in t he compound for 2 to 3 m inu tes; removing item (s) from fingerpr int rem over

compound and allowing them to drain; immersing item(s) in a second tank

conta ining clean dr y cleaning solvent a nd t horoughly rinsing; an d after rin sing,drain ing and drying th e item(s).

S o lv e n t C l e a n i n g F o l lo w e d b y F i n g e r p r i n t R e m o v a l

This process is accomplished by completing the cleaning steps described for

solvent cleaning, followed by perspira tion a nd fingerprint removal. Figure 2-19

details th e steps involved.


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Figure 2-18. Fingerprint r emoval operat ions.


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2-23

Va p o r D e g r e a s in g

Cleaning by vapor degrea sing. This pr ocess differs from th e previous processes

in removing conta mina nts from the items. As you r ecall, cleaning ma terials

were not heated. In th is cleaning process, we are going to heat nonflamm able

solvents and use th e vapors to throughly remove heavy oils, greases, and wa x.

This process should not be used on items th at can be damaged by heat. The

degreasing process is quite simple but m ust be done only in special equipmentbecau se of the h azar ds involved.

Material used in vapor degreasing. The mater ials used in vapor

degreasing are kn own a s chlorinat ed solvents such a s trichloroethan e-

1,1,1. Trichloroeth an e-1,1,1 is a clear, non-flam ma ble solvent a nd can

be used either in liquid form or in vapor form after hea ting. It ha s a

boiling point of 165F. These mat erials will not remove fingerpr ints,

ru st, or scale. Its pr imar y purpose is to remove hea vy oils, greases, and

wax. En vironm enta lly friendly degreasers are also available and are

highly recommended for this process.

Equ ipmen t for vapor degrea sing. This cleanin g process should only be

done in properly designed equipment t hat may vary in size and sha pe.

The ma nu factu rer s guide must be car efully followed. Figur e 2-20 shows

the pa rts of a typical vapor degreaser.

Safety precautions for cleaning by vapor degreasing are: (WARNING)

VAPOR HARMFUL!

1. Use only with adequa te ventilation.

2. Avoid pr olonged or repea ted brea th ing of vapor.

3. Avoid pr olonged or repea ted cont act with skin.

4. Do not tak e intern ally.

5. Conta ct with flam es or hot glowing sur faces ma y form corr osive

acid fumes.

6. The man ufacturers man ua l must be used as a guide, with

par ticular a tten tion focused on cleaning th e tan ks.7. Wear protective clothing, gloves, apr ons, an d goggles.

How the vapor degreaser cleans. This method of cleaning rem oves

hea vy oils an d greases. The cleaning a ction is due t o vapors conden sing

on the cool item, which t hen dissolves th e greases a nd oils and rinses

them from the item as illustra ted in figure 2-21. Cleaning steps

involved in vap or degrea sing ar e as follows:

1. Place items on racks or in baskets. Place in such a way th at when

th e greases a nd oils drain, th ey wont be tr app ed in pockets or crevices.

2. Lower th e items slowly into the vapor ar ea at a r at e of 10 to 12 feet

per minu te to prevent th e escape of vapors from th e tan k.

3. When vapors stop conden sing on th e item s, slowly rem ove from

tank.

4. If some conta mina nt st ill rem ain s on th e item, cool to room

temperatur e, then repeat the above steps.

5. Remove slowly from vapor ar ea an d allow item s to cool.

6. No dryin g process is requ ired.


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Figur e 2-19. Solvent clean ing followed by finger prin t rem oval.


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Figure 2-20. Vapor degreasing.

Figure 2-21. Vapor Degreasing an item.


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Va p o r D e g r e a s i n g F o ll ow e d b y F i n g e r p r i n t R e m o v a l

This clean ing process is a combina tion of two oth er cleanin g processes. If the

item h as a critical sur face an d is coated with h eavy oil or grease, the heavy oil

or grease mu st be rem oved before the fingerprin t r emoval compound is used on

the critical surface. Clean th e item by vapor degreasing first to remove theheavy oil or grea se. Allow th e item to cool un til it reaches r oom t empera tur e.

Then clean the item in th e fingerprint removal compound to remove any water

soluble contam inan ts on th e critical sur faces of the item.

For environmentally safe substitutes for Trichloroethane 1,1,1, refer to the

Environmental Products Catalog, Defense Supply Center, Richmond, VA,

ht tp://www.dscr.dla.mil. Manu factu rers recommen dations an d Material Safety

Data Sheets (MSDS) should be consulted.

J e t S p r a y Wa s h i n g

Procedures such as solvent cleaning that use solvents, which have

chloroflourocarbons in them or are ozone depleting chemicals or water

polluta nt s, are being replaced by environmen ta lly safer cleaning processes. J etspra y washing is a cleaning meth od designed to operate with th e lowest buildup

or generation of conta minan ts which pollute th e environmen t.

Items with heavy or light greases or oils are placed into units which are

preheat ed to temperatu res over 200 F. A clean ing compound is placed in the

un its an d mixes with t he very h ot water which is jet spr ayed with considerable

force onto the items u ntil th ey are clean .

As the items ar e being jet spra yed, th e conta mina nt is scra ped or skimmed from

the su rface of the solvent an d compr essed into a sm all unit for ea sy disposal.

The liquid portion of the cleaning compound provides for safer disposal into

norma l water dr ainage systems. The items receive thorough cleaning and ar e

very hot at th e end of th e clean ing cycle. No special drying techniqu e is

necessary.

Regardless of the high temperature, jet spray washing will not remove

fingerprints, perspira tion, etc. from meta l items with critical surfaces. The

finger prin t removal compound process will still be necessary. However, this

process does not provide the corrosion pr otection of th e chlorin at ed solvents .

Abr a s i ve B l a s t

The abrasive blast process consists of directing a high velocity stream of an

abra sive ma terial against th e surface of th e item. It should be used on sur faces

wher e th e abra sive action will not affect th e fun ction of th e item su ch as rough

castings. The choice of abra sive mat erials is so large th at almost an y type ofsurface finish ma y be obtained. These mater ials include harden ed cast steel

shot, san d, garn et abrasives, an d glass beads. The equipmen t used in this

process ran ges from sma ll blast cleaning cabinets to large blasting rooms a nd

open a ir blasting operations.

In general, th e following steps are performed:

Protect yourself with appr oved pr otective equipment.

Mask off any portions of work t ha t mu st n ot be blasted.


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Adjust pressu res of compressed a ir t o the t ype of sur face being clean ed,

60 to 100 psi for hard materials or 30 to 50 psi for the softer materials.

Direct the stream of abrasive at a 90 angle to the work surface and

move nozzle only as fast as t he su rface is clean ed.

If surfaces are dusty and have metal chips clinging to them after

blastin g, blow off with compressed a ir or rinse in a n inh ibited cleanin g

solution.

If iron du st a nd meta llic part icles cont inue t o adhere t o metal sur faces

after rinsing, demagn etize items pr ior to furth er cleaning.

Al ka l i ne C l ean i n g

The alka line cleanin g pr ocess, as pictu red in figur e 2-22, consist s of soaking the

items in a lkaline cleaner solution a nd r insing in clean h ot water a bove 180F.

Items cleaned by this pr ocess ar e of a simple constr uction ha ving noncritical

sur faces. Alka line clean ing will rem ove shop dirt , soil, oily and wa ter -soluble

contaminants, and heavy waxes.

El ec t r oc l ean i ng

This process consists of immer sing the item in a solution an d ma king th e iteman elemen t of an electrochemical cell. It mu st be rinsed in clean h ot water above

180F. Figure 2-23 illustra tes th e removal of rust by electrocleaning.

E m u l si o n C l e a n i n g

Figur e 2-24 shows th e emulsion clean ing process. This process consist s of

subjecting the item to a pressure spray or soaking in a tank of grease

emulsifying, solvent-soluble cleaning compound to remove solvent-soluble

grea se, oil, dirt , etc. from var ious su rfaces.

Figure 2-22. Alkaline cleaning.


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Figur e 2-23. Electr oclean ing.


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Figure 2-24. Emulsion cleaning.

S t e a m C l e a n i n g

The stea m cleaning process consists of subjecting t he item t o a strea m of stea m

with a n a dded cleaning compoun d followed by steam alone. Figure 2-25 depicts

a typical use of steam cleaning to remove heavy greases from automotive

equipment, such as trucks.


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Figure 2-25. Steam clean ing.

Abr as i ve B la s t ( Hon i ng P r oces s )The honing abr asive blast process consists of subjecting th e items to a st ream

of atomized water containing a fine particle size abrasive and a corrosion

inhibitor. It will rem ove light coats of ru st or scale. Equ ipmen t similar to th at

shown in figur e 2-26 is used for abr asive blastin g. Steps involved in clean ing by

th is process are as follows:

Place item into th e cleaning cham ber an d close door.

Thru st arms th rough rubber sleeve openings. Make sure tha t sleeves

fit tightly around t he wrist.

Hold item in one hand, while directing the blasting stream with the

other.

Continu e the a brasive blasting u ntil all contamina tion is removed. Remove cleaned item from cabinet and dip it in a tank of corrosion

inhibited rinse water.

Dry th e item as soon as possible after rinsing.


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Figur e 2-26. Abrasive blast cleanin g honin g process.

Sof t Gr i t Blas t

The soft grit blast process consists of subjecting the item to a high velocitystrea m of water containing a soft a brasive mater ial.

Ul t r a s on i c C l ean i ng

Ultrasonic cleaning should be used on nonabsorbent materials such as those

foun d in electronic devices. This pr ocess consist s of susp endin g the item to be

cleaned in a cleaning agent , th en directing th e force of high frequency sound

waves through th e agent against t he surfaces to be cleaned. The soun d waves

set up an agitation action along th e surface, so in r eality the bubbles scrub t he

contaminant off the surface by means of an implosion as shown in figure 2-27.


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Figure 2-27. Ultrasonic cleaning.

DRYING P R O C E D U R E S

Immediately after cleaning the item, it must be thoroughly dried to rem ove an y

cleanin g solutions or rem ainin g m oisture. Figur e 2-28 illust ra tes the approved

drying pr ocedures.

Dr y i ng W it h Com pr es s ed Air

The air for drying must be free from oil, dirt , and moistu re. Dry all surfaces of

the item by applying th e clean air u ntil all solvent s disappear.

Dr y i ng W it h Oven sThis is done by placing th e item into a hea ted a ir oven. The oven sh ould be well

ventilated and temperature controlled.

D r y i n g Wi t h I n f r a r e d L a m p s

This is done by placing the item between rows of infrar ed lamps. This is a

commonly used procedure for drying.

Dr y i ng b y Wi p i ng

This is done by wiping the item with clean , lint -free cloth s. It is difficult t o wipe

areas th at have blind holes and u ndercuts.

D r y i n g b y D r a i n i n g

This drying process is used only when the final step in cleaning involves a

petroleum solvent, and the item is to be preserved with a material using a

petroleum solvent a s a thinn ing agent.


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Figure 2-28. Drying procedures.


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C h e c k u p

What is th e first operation in th e preservat ion of meta l items?

What type of contam inant is removed by solvent cleaning?

Name the t hree sa fety featur e requirements of a solvent cleaning tank .

When can drying by draining be used to dry an item?

What are the requirements when drying with compressed air? What clean ing process mu st be used on items h aving a critical sur face?

How long mu st an item be in a fingerprint r emoval compound?

What must be done to an item after removing it from fingerprint

rem over compound (MIL-C-15074)?

C LEANING AND DRYING P RACTICAL E XERCISE

Objec t ive

The stu dent will answer questions on the p roper selection an d application of th e

various cleaning processes an d dr ying pr ocedures.

G e n e r a l D i r e c t io n s The exercise will requir e appr oximat ely one class per iod, includ ing th e

critique for complet ion.

The instructor will hold the critique when the students have completed

the practical exercise.

Cond uc t o f Exe r c i s e

S i t u a t i o n

You ha ve received classr oom inst ru ction on t he selection of clean ing pr ocesses

an d drying procedur es. Your job is to produce properly cleaned an d dr ied items.

R e q u i r e m e n t N o . 1. Answer the following questions on cleaning:

1. What cleaning materials may be used for solvent cleaning?

2. Why is it necessary to wear protective clothing during cleaning operations?

3. What contaminants are removed using solvent cleaning?

4. Are fingerprints removed by solvent cleaning?

5. What is the cleaning requirement for an item with a crit ical surface?

6. What cleaning process uses sound waves to create a cleaning action?

7. After a n item is cleaned in t he chemical process alkaline cleaning, what

must be done before we dr y or pr eserve the item?

8. What processes may be used to remove insoluble tightly adhering

contaminants?

9. What process is used to remove heavy greases from automotive equipment

such a s tru cks?


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10. If a cleaning compound is used in t he steam cleaning process, what mu st be

done immediately after th e cleaning compoun d is tu rn ed off?

11. What ar e the four general types of contam inants?

12. What m ust be considered in th e selection of a cleaning process?

13. What ar e the basic cleaning requirements?

14. What a re th e recommended safety features r equired on a solvent cleaning

tank?

R e q u i r e m e n t N u m b e r 2 . Answer the following questions on drying:

1. Why must an item be dried following cleaning?

2. Which pr ocess will be used if an item is cleaned by a solvent cleaning process

and is to be preserved with a mat erial using a petroleum solvent a s a th inning

agent?

3. Which drying procedures use heat?

4. What is meant by "Prepared" compressed air?

C r i t i q u e

Instr uctor will call on class members t o give the an swers to th e questions.

C a r e o f Ar e a , T r a i n i n g A id s a n d E q u i p m e n t

Not applicable.


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2-36

ELE CTROSTATIC DISCHARGE CONTROL

E LECTROSTATIC D ISCHARGE

We have been aware for quite some time that static electricity can impose

dam age on m etal oxide semiconductors (MOS). More r ecent ly, we have become

aware of the sensitivity of other parts to electrostatic discharge (ESD) through

use, tes ting, an d failure an alysis. Sources of ESD p olicy include MIL-W-87893and MIL-HDBK-773.

Trends in t echn ology are t oward greater complexity an d const ruction. Design

features of current microtechnology have resulted in parts which can be

destroyed or damaged by ESD voltages as low as 20 volts.

Various electrical and electronic parts which have been determined to be

sensitive to electrosta tic voltage levels commonly generat ed by pr oduction, t est,

opera tion an d maint enan ce personnel include:

Microelectr onic and semiconductor d evices.

Thick a nd t hin film r esistors.

Chips an d h ybrid devices.

Piezoelectric crysta ls.

All subassemblies, assemblies, and equipment conta ining these p art s n ot

ha ving a dequat e protection circuitry ar e also ESD sensitive (ESDS).

Materials which are prime generators of electrostatic voltage are common

plastics such as polyethylene, vinyls, foam, polyurethane, synthetic textiles,

fiberglass, glass, an d r ubber.

Actions which cau se th ese and other m ater ials to genera te electrostat ic voltages

are th e sliding, rubbing, or separ ation of mat erials. These movement s can

frequen tly resu lt in electrosta tic voltages of 15,000 volts.

Materials can be ra nked in a ccorda nce with their ability t o become positively

cha rged with respect to other mater ials. This ra nking is known as a

tr iboelectr ic series. Mate rial upperm ost in th e series becomes positively char ged

when ru bbed with a m ater ial lower in the series. The mat erials lower in the

series become negat ively charged. Conditions such as cleanliness, variat ion in

chemical composition an d pr ocesses, hu midity, and th e mechan ics of rubbing or

separa tion affect th e series to a great extent. Thus t he ra nking of elements or

compoun ds in th e series will not always be reproducible. One of th e man y

versions of th e ser ies follows.

Positive (+)

Air

Human hands.

Asbestos

Rabbit fur

Glass

MICA

Human hair

Nylon


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Wool

Fur

Lead

Silk

Aluminum

Paper Cotton

Steel

Wood

Amber

Sealing wax

Hard ru bber

Nickel, copper

Brass, copper

Gold, platinu m

Sulfur

Acetate rayon

Polyester

Celluloid

Orlon

Polyurethane

Polypropylene

PVC (vinyl)

KEL F

Negat ive (-)

Silicon Teflon

Protection of electrical and electronic ESDS parts assemblies and equipment can

be provided th rough t he implemen ta tion of low cost ESD contr ols. Lack of

control has resulted in high repair cost, excessive equipment downtime, and

reduced mission effectiveness because susceptible parts are being damaged

dur ing processing, assem bly, inspection, h an dling, packaging, shipping, storage,

stowage, testing, installation, and maintenance throughout the equipment's life

cycle, both at th e man ufacturer's a nd t he u ser's facility.


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The effects of ESD on electrical and electr onic items a re n ot gener ally recognized

becau se they ar e often masked by rea sons such as:

Failures due to ESD are often analyzed as being caused by electrical

overstress due to transients other th an static.

Failure caused by ESD is often incorrectly categorized as random,

unknown, manufacturing defect, or other, due to improper depth offailure an alysis.

Few failur e an alysis laborat ories ar e equipped with scan ning electron

microscopes or other equipment and technology required to trace

failures t o ESD.

Some programs a nd projects a re a ccepting high operat ional failure r ules

as n ormal an d simply procur e more spar es instead of recognizing a nd

solving the basic ESD problem.

Belief of personnel that static controls are necessary, for only MOS at

the part manufacturer's site and for handling of ordnance, is

widespread.

Also common is the belief that an ESDS part "protected" by a diode,

resistive network or other protective part is non-ESDS.

Static discharge failures do not always occur immediately following

exposur e but ma y result in latent defects.

In order t o protect ESDS devices while handling an d packaging, it is importan t

to provide a condu ctive path to groun d in the environm ent . Such a pat h should

provide for ra pid dissipat ion of th e sta tic electr ical cha rge. Figur e 2-29

illust ra tes a typical sta tic protective work sta tion which uses a condu ctive table

and floor mats a s well as a wrist str ap to groun d th e operat or.

Because the human body is a conductor, it may be effectively grounded.

Cloth ing, however, will genera te an d ret ain electrostatic cha rges, somet imes as

high as 30 th ousan d volts. These sta tic char ges will not bleed off whengrounded.

People ha ndling ESDS items sh ould wear long sleeved ESD pr otective smocks

or close-fitt ing, short sleeved shirt s or blouses .

If long sleeve clothes are worn, the sleeves must be rolled up or else covered

with a n a ntistat ic sleeve protector, called a gaun tlet, from th e bare wrist as far

up as th e elbow. When gaun tlets are worn, the clothing does not have to be

made of ESD pr otective mater ial.

Antistat ic garm ent s can be made by trea ting cott on or synt hetic cloth es with an

an tistatic chemical agent in final rinse during launder ing. Each time th e clothes

are washed, the antistatic agent must be reapplied.

The pr oper cont rol of sta tic electricity is often overlooked in t he field. Dur ing

in-field replacement of sensitive component s or print ed circuit boards, t he n ew

component or boar d ma y be destroyed or degra ded by an un grounded service

techn ician . An ESD pr otective field service kit is designed to help solve thes e

problems for the field service technician and for field packaging operations as

well.


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Figur e 2-29. P rotective Work Sta tion.

The ESD protective field service kit includes a grounded work surface mat

(typically 2' x 2') an d a conductive wrist str ap.

Some field work surface protective mats contain pockets which are sewn into the

mat and can be used to store ESDS components or boards wh ile tra nsporting to

and from the field. For larger boar ds, the mat is folded around th e boar d to

provide pr otection (the E SDS item may require additional protection).

The ground lead cont ains a cur rent limiting series resistor t o protect th e worker

from being shocked in case of accident al cont act with line volta ge.

For proper operat ion, th e wrist stra p cable is conn ected to the m at at t he sam e

term inal where the ground lead is also conn ected. Then th e ground lead is

connected to a bare meta l part of the m ain fram e of the system conta ining thepar t being worked on.

Packaging for protection for ESDS items requires the use of appropriate

mat erials. Protection sha ll be provided to prevent ph ysical dam age and to

maintain leads and terminals in an as-when-manufactured condition during

handling and tr ansportation.


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An acceptable means of packaging ESDS items would be to first place them in

an an tistat ic or stat ic dissipative environm ent by wrapping an d/or cushioning

them in one or more of the following materials:

MIL-PRF-81705, type II barrier material, transparent, waterproof,

electrostatic protective.

PP P-C-795, class 2 an tistat ic (pink tint ed) cush ioning mat erial, flexible,cellular , plast ic film.

PPP-C-1842, type III, type A or B cushioning material, plastic open cell.

PPP-C-1797, type II cushioning material, resilient, low density,

unicellular, polyproplene foam.

After being protected by a nt istatic or st at ic dissipat ive ma terials, th ey

ma y then be shielded in a ba g or pouch conforming to MIL-PRF -81705,

type I bar rier m ater ial water vaporproof, greaseproof electrostat ic and

electr omagn etic protective (opaque).

Marking of ESDS items will be per MIL-STD-129, which requires that unit

packs, interm ediate and exterior conta iners be marked with th e ESDS device

cau tion label, which is a trian gle and r eaching hand . All unit packs shall bemarked with the ESD label prescribed by ASTM D 5445, Standard Practice for

Pictorial Markin gs for Han dling of Goods. The symbol an d letter ing sha ll be

mar ked in black on a yellow backgroun d. The label sha ll include the E SD

sensitive device symbol and the words ATTENTION STATIC SENSITIVE

DEVICES and the statement HANDLE ONLY AT STATIC SAFE WORK

STATIONS. Unit packs that a re not overpacked and are used as exterior

containers sh all be mar ked with th e unit pa ck label.

Intermediate and exterior containers shall also be marked with the ESD

sensitive devices symbol and the words ATTENTION OBSERVE

PRECAUTIONS FOR HANDLING ELECTROSTATIC DISCHARGE

SEN SITIVE DEVICES. One 2 by 2-inch label sha ll be placed on th e

ident ificat ion-ma rked side of th e int erm ediat e conta iner . Two 4 by 4-inch labels

sha ll be placed on ea ch exterior cont ainer th at exceeds one-half cubic foot. One

label shall be placed on t he identification-marked side, and one label shall be

placed on the opposite side. Sma ller exterior conta iners sha ll be mark ed in the

sam e man ner except th at t he 2 by 2-inch label ma y be used in lieu of th e larger

label. The min imum size of the symbol shall be five-eights of an inch mea sur ed

vertically at th e base of th e trian gle.

C h e c k u p

What actions cau se ma terials to genera te electrostat ic voltages?

Are certain m aterials when placed together more apt to genera te stat ic

electricity th an others?

How can electronic items be pr otected from stat ic electr icity?

What documen t covers th e basic ma rkings r equired for E SD sensitive

items?


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PRESERVATIVES

GENERAL

Conta ct preservatives are ma terials th at a re applied to, or come in cont act with,

items to protect them from deterioration resulting from exposure to

environm enta l conditions during shipmen t an d storage.

Some preservatives protect items by providing a physical barrier against

moistur e, air, and other agents of corr osion. These are conta ct preservatives.

Preservatives should be applied whenever items require protection against

deteriorat ion. Some met als such as gold, platinu m or beryllium ar e immun e to

corrosion under ordinary conditions and seldom require the application of a

preservative.

Many items susceptible to corr osion can be m ade less su bject to deterioration by

the application, at the time of manufacture and subsequent operations, of a

protective coating or plating which rema ins an integral part of the item during

its useful life. Such coatings and platings ar e called perman ent pr eservatives.

Many items, however, because of close tolerances, operating characteristics such

as rolling, sliding, or bearing surfaces, or other limiting factors cannot be

protected with a perm an ent coat ing, but mu st be protected durin g shipment an d

storage by temporar y preservatives. These preservative mat erials are applied

after th e item has been ma nu factu red an d must be removed before the item can

be used.

AP P LICATION R EQUIREMENTS

Most contact preservatives are oily or greasy in nature, and vary greatly in

chemical composition and consistency; therefore, they cannot be used

indiscriminat ely on all kinds of mat erials. They may even destroy the

usefuln ess of an item d ue t o the difficulty of rem oval.

A preservative may penetrate into unwanted areas and cause swelling or

decomposition of th e ma ter ial, or r educe its electrical condu ctivity.

Petr oleum p reserva tives are a pplied to th ose meta l surfaces on wh ich corr osion

in an y form would impair th e usefulness of the item or a ssembly.

E XCEPTIONS TO AP P LICATION R EQUIREMENTS

Petr oleum preservat ives ar e not ap plied to surfaces which a re pr otected by solid

film lubricant s, plastic or paint coatings. They are not norma lly used on

noncritical metal surfaces that are inherently resistant to corrosion such as

items made from copper, nickel, chromium, brass, bronze, or other corrosion

resistant metals.

Oily type preservatives are not app lied to items tha t ar e vulnerable to damage

by the pet roleum ingredients su ch as textiles, corda ge, plastics, mica, r ubber,

paper, felt, leather or prelubricated bu shings.

Preservatives are not applied to certain types of electrical and electronic

componen ts or equipm ent such a s conden sers, electr ical conn ectors, distr ibutor

rotors, circuit breakers, fuses, switches, resistors and rectifiers.


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Preser vatives are not applied to any items which would suffer da mage to th e

mechan ism or str uctur e, or wher e malfunction or un safe opera tional conditions

would r esult from th e application or r emoval of th e preservat ive.

N e e d fo r T e m p o r a r y P r e s e r v a t i v e s

A great number of military supplies are made of such materials or are so

complex that it is either impossible or impractical to apply a permanentpreservat ive to them. Working par ts of ma chiner y, for example, ar e often

precision fit an d mu st be free from a ny type of coating when in use.

Some bare met al items mu st be given a coating wh ich will protect t hem from t he

time they are made un til th ey are used. This coating must be readily applied

and ea sily removed. Petr oleum t ype preservatives ar e used for this purpose.

Other metal items must be protected by volatile corrosion inhibitors (VCI) or

desiccated packs.

Formerly, lubricating oils and greases were used. This was better t ha n no

preservat ive, but these oils and greases pr oved inadequa te for the full protection

desired.

To achieve full protection, ther e ar e two kinds of additives used in pr eservatives

to help preven t corrosion. They are kn own as inh ibitors an d polar compoun ds.

An inhibitor is a su bstan ce that slows down or prevents ru sting by chemical

action. A polar compound is a su bstan ce th at gives water displacing properties.

Various t ypes of preservative oils and greases conta ining inhibitors and polar

compoun ds a re referred t o in m ilitar y pr eservation specifications.

SELECTING THE P RESERVATIVE

It should be realized that there is no one preservative suitable for all purposes.

Selecting th e right pr eservative must be as carefully considered a s selecting a

proper cleaning pr ocess. In m ost instan ces, selection of the preservat ive ha s

been prescribed in procurement documents, process data sheets, special

packaging instr uctions, or similar form s.

Care must be taken that the preservative selected will not damage the

mechanism, str uctur e, or function of the item, either when applied, in use, or

dur ing removal. In ma king a selection, the following considera tions should be

used.

I t em Com p os i t ion

As shown in figure 2-30, the composition of an item determines whether it needs

to be preserved and, if so, what kind of preservat ive will be used. Genera lly,

meta l items are pr eserved with an y of the petroleum type compounds.

S u r f a c e F i n i s h

If the item is forged, stam ped, rough cast, rough ground, or rough m achined,

and has nonprecision surface, it may be protected by almost any of the

petroleum type preservat ives. On the other h an d, items with pr ecision surfaces

should be protected with an oil or light grease type preservat ive. Figure 2-31

illustra tes var ious sur face finishes.


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Figur e 2-30. Composition of th e item .

Figur e 2-31. Sur face finish of th e item .

Com pl ex i t y o f Cons t r uc t i onItems should be cleaned, dried, and preserved in as simple a unit state as

possible. Disassem bled item s with close toleran ces should n ot be coat ed with

heavy greases or ha rd dr ying types of preservatives which m ay inter fere with

or prevent reassem bly. If disassembly is not pr actical or the item is highly

irregu lar with blind holes and crevices, heavy pr eservat ives may be difficult to

app ly an d impossible to rem ove. Complexity of const ru ctions is depicted in

figur e 2-32.


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E x t e n t o f P r o t e c t i on R e q u i r e d

When an item is made from two different materials, for example, metal and

plastic, only th e meta l part of th e item would be coated with a pr eservat ive. In

the case of the m allet, as sh own in figure 2-33, no petroleum preservat ive would

be required.

Eas e o f, or Need fo r , Rem ova lThe user of th e item mu st be kept in mind when choosing the preservat ive. The

time required for removal, the equipment available, and the necessity for

removal are of importan ce to th e user. Figure 2-34 illustra tes this

consideration.

Figur e 2-32. Complexity of const ru ction.

Figure 2-33. Extent of protection r equired.


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Figur e 2-34. Ea se of, or nee d for, removal.

O t h e r F u n c t io n s o f t h e P r e s e r v a t i v e

In some instances, the nature of the item or assembly requires that the

pres erva tive also act as a lubricatin g oil or hydra ulic fluid. Figur e 2-35 shows

items that h ave this requirement . In such cases, the lubricating requirement s

must be met first and the pr eservative properties secondarily.

C ONTACT P RESERVATIVES

There a re several different temporar y contact preserva tives. We will describe

only the m ore frequent ly used.

MIL-P RF -16173, Gra de 1 , Har d Fi lm, Cor r os ion Pr even t ive Compou nd , Solvent Cutb ack ,

Co ld App l i ca t i on (f or m er l y P - 1)

Des cr i p t i on a n d Ch a r a ct er i st i cs

This is an a spha lt compound dissolved in petroleum solvent. It dries to a ha rd,

thin, opaque film on the item when th e solvent evaporat es. Flashp oint of the

solvent is 100F. It is suitable for protection of noncritical meta l items t ha t ar e

stored outd oors or where a "dry-to-touch" film is desired. In m ost cases,

overwra pping of an item coat ed with t his compound is n ot necessary, due to th e

har dness of the film.

I n t en d ed Uses

For preservation of items a nd equipment when r emoval prior t o using the itemis not required. Exam ples of items preserved are simple han d tools, nu ts,

washer s, cha ins, etc.

Met h od s of A p p l ica t ion

This preservative can be applied by brush, dip, or spr ay. For effective spray

application, th e preservat ive mat erial requires dilut ion with dry cleaning

solvent to a greater degree tha n for dipping or bru shing.


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Figure 2-35. Other fun ctions of the pr eservative.

M I L-PR F-16173 , Gr a de 2 , So ft F i lm , Cor r os i on P r even t i ve Com pou nd , Sol ven t Cu t ba ck ,

Cold App l ica t ion ( form er ly P -2)

Des cr i p t i on a n d ch a r a ct er i s t i cs

This is a solvent-dispersed, corrosion-preventive compound, which deposits a

th in, soft film on th e item. Fla shpoint of solvent is 100F. Items preserved with

this requ ire a pr eliminar y greaseproof wrap or ar e enclosed in a gr easeproof bag

when a submeth od requires a bag as th e preliminary conta iner, becau se it is a

soft pr eservative an d will be absorbed by the packing mat erials.

I n t en d ed UsesIt is used t o protect int erior a nd exterior meta l surfaces destined for extended

undercover storage. Examples of items preserved are pipe and tube fittings,

pistons, piston rings, bearings and instruments, and exterior surfaces of

ma chiner y. It is used out doors for limited periods only.

Met h od s of A p p l ica t ion

It is usu ally applied by brush , dip, or spr ay.

M I L-PR F-16173 , Gr a de 3 , Wa t e r Di s p lac i ng , Cor r os i on P r even t i ve Com p oun d , So lven t

Cu t b ack , Co l d App l i ca t i on ( fo r m er l y P -3 )

Des cr i p t i on a n d Ch a r a ct er i st i cs

This is a solvent-dispersed, water-displacing corrosion-preventive compound,

which deposits a thin, nondrying film on the item upon evaporation of the

solvent . F lashp oint 100F. Due to its chemical composition, th is ma ter ial has

a great er att raction to metal surfaces th an wa ter an d actually displaces water

from m etal su rfaces.


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I n t e n d e d U se s

This water -displacing preser vative is inten ded for u se where fresh or salt wa ter

must be displaced from corrodible surfaces and for the protection of interior

sur faces of ma chinery and equipmen t un der cover. Exam ples of items on which

it is u sed ar e ra diators, boilers, and cooling systems.

Met h od s of A p p l ica t ionThis preservative is generally applied by bru shing, dipping, or spr aying when

used to preserve exterior sur faces. When u sed on inter ior or enclosed sur faces,

it ma y be app lied by filling or flushin g.

M I L-PR F-16173 , Gr a de 4 , T r a ns p a r en t F i l m , Cor r os i on P r even t i ve Com poun d , Sol ven t

Cu tba ck , Cold App l ica t ion ( form er ly P -19)

Documents

Military Preservation Guide