L 4A_2b Tab of Factor

Table 2 Environments A & B: Typical Protective Systems

Interior dry and interior with occasional condensation

Dry film thickness

Cost comp Likely time to first maintenance in years

Comments upon initial systems

Repaint - likely system

Comments upon repaint system

(a) (b)

prevent steel corrosion

maintain appearance hygiene etc

P1

Off site:

Blast to Sa 2, ISO 8501-1

Medium Profile ISO 8503 Part 1

Coat 1 Blast Primer Type 1, 11 or 111

Coat 2 or Oil Based Anticorrosive Primer

15(1)

50

(50)

1. Ignore this DFT in calculating total thickness required for protection.

2. Accurate costing possible.

3. Controlled environment for preparation/priming.

4. Pre or post fabrication priming possible. If post

Prepare and spot prime - oil based anticorrosive Primer plus one or two coats oil based finish.

Spot priming should be less than 1% Top-coats only refurbished overall so maintenance relatively straight-forward.

On site:

Rectify transit/erection damage with Coat 2 Primer

Coat 3 Oil Based Undercoat

Coat 4 Oil Based Finish

Total DFT

Total DFT using micaceous Iron oxide pigmented undercoat

Total DFT using Micaceous Iron oxide pigmented undercoat and finish

25

35

110

130

150

20+

20+

20+

7

7-12

7-12

fabrication, omit coat 1.

5. Total system can be applied on site see (4) above. Cost is likely to increase. Quality control is more difficult.

6. The use of micaceous iron oxide pigmented undercoat and finish give better edge protection.

7. Coats 3 & 4 can also be replaced with one coat of a high build finish.



Dry film thickness

Cost comp

Likely time to first maintenance in years


Repaint - likely system Comments upon repaint system

(a) (b)



P2 On site:

Manual/Mechanical preparation to St 2, ISO 8501-1

Coat 1 Oil Based Anticorrosive Primer



Total DFT

Total DFT using micaceous iron oxide pigmented undercoat

Total DFT using micaceous

50

25

35

110

130

150

20+

20+

20+

5(1)

5+(1)

5-7(1)

1. light millscale, rust in pits will not be removed. This may cause paint detachment before the top coats need refurbishing.

2. Coats 2 & 3 can be replaced with 1 coat of a high build finish.

3. The use of micaceous iron oxide pigmented undercoat and finish will give better edge protection.

Prepare spot prime oil based Anticorrosive Primer bring forward with oil based under coat apply 1 or 2 coats of finish overall.

OR

1 coat high build finish.

May require up to 25% priming & bringing forward failure due to millscale detachment unpredictable.

Planned maintenance budgeting difficult.

iron oxide pigmented undercoat and finish

P3

On site:


Coat 1 Non oxidising 'grease' paint or propriety 'anticorrosive' compound

Coat 2 As coat 1

Total DFT

100+

100+

200+

20+

20+

not

app

1. This process is for hollow encased steelwork. It is not decorative.

2. Check risks in the event of fire.

3. Some manufacturer's may recommend a 'penetrating' primer.

Refurbish with original material or similar.

Establish consequence of increasing the total film thickness in the event of fire.



Dry film thickness m

Cost comp




(a) (b)



G1

On site:

Galvanize - pr EN 1029

85

20

not applicable

Size limitations.

Not decorative.

Not readily cleaned in service. *Life using galvanized fasteners.

Oil based anticorrosive primer calcium plumate pigmented (lead) containing - T - Wash or 2-pack etch primer similar to Type 1 Blast primer 1 coat oil based undercoat 1 coat oil based finish.

Corrosion products must be washed prior to painting lead - containing primers impose limitations. T Wash must be rinsed off thoroughly.

AS1/ZS1

Off site:

Zinc or aluminum spray to BS 2569 - sealed Aluminium, Unsealed zinc

100 100

20+ 20+

not applicable

No size limitations.

Not decorative, retains dirt, oil etc., readily.

Not readily cleaned in service. * assumes fasteners treated to same standard.

Non lead containing oil based anticorrosive primer

1 coat oil based undercoat

1 coat oil based finish.

Corrosion products must be removed before priming.

Table 2 Environment C: Typical Protective Systems

Interior frequent condensation

Dry film thickness m

Cost comp




(a) (b)



P4

Off site:



Coat 1 Blast Primer Type 11 or 111

Coat 2 One-pack Chemical Resistant Primer

On site:

Rectify transit/erection damage with One-pack

15

75


2. Zinc containing (type III) primer normally not used where direct chemical attack predicted. Consult manufacturer.

3. May be MIO pigmented.

4. Small sections

Prepare, prime with One-pack Chemical Resistant Primer, bring forward with one coat of Coat 3 type undercoat and apply Coat 4 type finish overall

These products dry by solvent evaporation alone when unmodified with oil. Adhesion of maintenance systems usually good therefore.

Chemical Resistant Primer.

Coat 3 One-pack Chemical Resistant Undercoat

Coat 4 One-pack Chemical Resistant Finish

Coat 4 Replacing with fill gloss One-pack Chemical Resistant Finish gives 25 :

5 25 :

(75)

75

75

225

175

250

15+

10+

15+

12

10

12

vulnerable to 'blocking' if bundled together at this thickness: consult manufacturer.

5. Total system can be applied on site see (4) above. Cost is likely to increase and quality control is more difficult.

6. Maximum resistance to direct chemical attack on paint film and for aesthetic reasons.

7. Maximum durability and chemical resistance.

Table 2 Environment C: Typical Protective Systems

Interior frequent condensation Dry film thickness m

Cost comp


Comments upon initial systems Repaint - likely system


(a) (b)



P5

Off site:




Coat 2 Two-pack Chemical Resistant Primer

On site:

Rectify transit/erection damage with Coat 2 type Primer.

Coat 3 Two-pack Chemical

15

75

(75)


2. Zinc containing (Type III) primer normally not used where direct chemical attack predicted. Consult manufacturer.

3. Coat 1 may be omitted if blasting is post fabrication.

4. Epoxy or urethane pitch or tar can be used for water resistance.

Prepare and apply one or two coats of coat 3, two pack chemical resistant finish.

OR

1 coat one-pack chemical resistant undercoat

1 coat one-pack

Preparation may include light blasting. Remember temperature humidity and intervals between coats are critical.

Refurbishing with one-pack chemical resistant undercoat and finish can be considered.

Resistant Finish

Coat 4 Two-pack Chemical Resistant Finish

Total DFT

75

75

223

15+

10+

5. Consult manufacturer for min temperature & max humidity requirements during application and curing.

6. Intervals between coats are critical, consult manufacturer. Ensure relevant information is written into specification.

chemical resistant finish.

Note: System P1, page 1 using MIO pigmented undercoat and finish can be considered at dft's of 130-150 m. It will not resist direct chemical attack or immersion. Likely time to first maintenance - 5 years (columns 'a' and 'b').

Consider also Galvanising - See system G1 (85 m dft). See page 22

Consider also Metal Spraying - See system AS1/ZS.1 (100 m dft). See page 22

Table 2 Environment D: Typical Protective Systems

Normal Inland Dry film thickness m

Cost comp




(a) (b)



P1

Off site:




Coat 2 or Oil Based Anticorrosive Primer

Onsite:

Rectify transit/erection damage with Coat 2 Primer

15

50

(50)


2. Accurate costing possible.


4. Pre or post fabrication priming possible. If post fabrication, omit coat 1.

Prepare and spot prime - oil based anticorrosive Primer plus one or two coats oil based finish.

Spot priming should be less than 1% Top-coats only refurbished overall so maintenance relatively straight-forward.



Total DFT

Total DFT using micaceous Iron oxide pigmented undercoat

Total DFT using Micaceous Iron oxide pigmented undercoat and finish

25

35

110

130

150

7+

10+

10+

5+

7-12

7-12

5. Total system can be applied on site see (4) above. Cost is likely to increase. Quality control is more difficult.

6. The use of micaceous iron oxide pigmented undercoat and finish give better edge protection.

7. Coats 3 & 4 can also be replaced with one coat of a high build finish.



Cost comp


Comments upon initial systems Repaint - likely system Comments upon repaint system

(a) (b)



P2

On site:





Total DFT

Total DFT using micaceous iron oxide pigmented undercoat

Total DFT using micaceous iron oxide pigmented undercoat and finish

50

25

35

110

135

150

6-10

6-10

8-12

3-5

3-5

5-7

1. light millscale rust in pits will not be removed. This may cause paint detachment before the top coats need refurbishing.


Prepare, spot prime with coat 1 type primer, bring forward with coat 2 type undercoat, finish overall with one coat type 2 undercoat and one coat type 3 finish OR 2 coats type 3 finish.

OR 1 coat high build finish.

May require up to 25% priming & bringing forward failure due to millscale detachment unpredictable.

Planned maintenance budgeting difficult.



Cost comp




(a) (b)



P4

Off site:





On site:

Rectify transit/erection damage with One-pack Chemical Resistant Primer.


15

75

(75)

75

75

225

15+

7-10




4. Small sections vulnerable to 'blocking' if bundled together at this thickness: consult manufacturer.

Prepare, prime with One-pack Chemical Resistant Primer, bring forward with one coat of Coat 3 type undercoat and apply Coat 4 type finish overall.



Coat 4 Replacing with full gloss One-pack Chemical Resistant Finish gives 25 m for final coat: Total DFT becomes

OR

Add Coat 5 - full gloss One-pack Chemical Resistant Finish giving additional 25 m:

Total DFT becomes

175

250

10+

15+

7+

7-10

5. Total system can be applied on site. Cost is likely to increase and quality control be more difficult.



Consider also Galvanising - See system G1 (85 m dft). See page 22

Consider also Metal Spraying - See system AS1/ZS.1 (100 m dft). See page 22

Table 2 Environment E: Typical Protective Systems

Normal Coastal Dry film thickness m

Cost comp




(a) (b)



P4

Off site:





On site:

Rectify transit/erection damage with One-pack Chemical Resistant Primer.


Coat 4 One-pack Chemical Resistant

15

75

(75)

75

75





Prepare, prime with One-pack Chemical Resistant Primer, bring forward with one coat of Coat 3 type undercoat and apply Coat 4 type finish overall.


Finish

Coat 4 Replacing with full gloss One-pack Chemical Resistant Finish gives 25 m for final coat: Total DFT becomes

OR

Add Coat 5 - full gloss One-pack Chemical Resistant Finish giving additional 25 m:

Total DFT becomes

225

175

250

15+

10+

15+

12

10

12





Polluted Inland Dry film thickness m

Cost comp




(a) (b)



P6

Off site:





Coat 3 Two-pack Chemical Resistant Undercoat

Onsite:

Rectify transit/erection damage with

15

75

125

(75)


2. This coat can be omitted if post fabrication blasting is carried out.


4. Consult manufacturer for min temperature and max humidity requirements during application and 'curling'.

Prepare and apply one to two coats of coat 4 type Two-pack Chemical Resistant Finish.

OR

one-pack moisture curing polyurethanes

Preparation may include light blasting. Remember, temperature and humidity and intervals between coats are critical. Refurbishing with a One-pack Chemical Resistant Finish can be

Coat 2 Primer, bring forward primed areas with coat 3 type undercoat.

Coat 4 to-pack Chemical Resistant Finish

Total DFT

OR

substitute Coat 4 One-pack Chemical Resistant Finish

Alternative process Total DFT

(125)

75

275

75

275

20

20

7-12

7-12

5. Interval between coats is critical consult manufacturer. Ensure relevant information is written into specification.

6. This is a useful alternative to a 2-pack paint as the final coat under cold conditions or where there are likely to be delays on site (includes 1-pack moisture-curling polyurethanes)

7. Glossy 1 or 2 pack Chemical Resistant Finishes will give lower DFT's (circa 25 m).

OR

Prepare and apply one or two coats One-pack Chemical Resistant Finish.

considered i.e. chlorinated rubber, vinyl or acrylic resin based. Also 1-pack moisture-curing urethane.


Polluted Inland Dry film thickness m

Cost comp




(a) (b)



P7

Off site:





On site:

Rectify transit/erection damage with 2 coats One-pack Chemical Resistant Primer.



15

100

(50) (50)

75

75





Prepare, prime with One-pack Chemical Resistant Primer, bring forward with one coat of Coat 3 type undercoat and apply Coat 4 type finish overall (1 or 2 coats).


Finish


Total DFT

Replacing with full gloss One-pack Chemical Resistant Finish gives 25 m for final coat:

Total DFT becomes

75

325

255(6)

15+

10+

15+

12

10

12




G1

Offsite:

Galvanise - pr EN 1029

85

10+

Not applicable

See notes under G1 page 22

3 Coat one or two pack chemical resistant paint systems 150-300 m dft

See notes under G1 page 22

AS2/ZS2

Off-site zinc or aluminium spray to BS 5269 - sealed

150

zinc 15+

Aluminium 20

Not applicable

See notes under AS1/ZS1 page 22 As noted in G1 above

See notes under AS1/ZS1 page 22

Table 2 Environment F: Typical Protective Systems


Cost comp



Comments upon repaint system (a) (b)



P1

Off site:





Onsite:

Rectify transit/erection damage with Coat 2 type Primer.

15

50

(50)


2. Accruable costing possible.



5. Total system can be applied on site. Cost is likely to increase. Quality control is more

Prepare, spot prime with coat 2 type primer. Bring forward with coat 3 type undercoat. Finish overall with coat 4 type finish.

Spot priming should be less than 1%. Bringing forward primed areas with undercoat retains original thickness.



Total DFT

Total DFT using a micaceous iron oxide pigmented undercoat

Total DFT using micaceous iron oxide pigmented undercoat and finish

25

35

110

130

150

8+

8+

8-12

3+

3-5

5+

difficult.


Table 2 Environment F: Typical Protective Systems


Cost comp




(a) (b)



P5

Off site:





On site:

Rectify transit/erection damage with coat 2 type Primer.

Coat 3 Two-pack Chemical Resistant

15

75

(75)

75




4. Epoxy or urethane pitch or tar can be used for water resistance.

5. Consult manufacturer for min temperature & max

Prepare and apply one to two coats of coat 3, Two-pack chemical resistant finish.

OR

1 coat One-pack chemical resistant undercoat

1 coat One-pack chemical resistant finish.

Preparation may include light blasting. Remember temperature, humidity and intervals between coats are critical. Refurbishing with One-pack chemical resistant undercoat and finish can be considered.

Finish

Coat 4 Two-pack Chemical Resistant Finish

Total DFT

75

225

15+

10+

humidity requirements during application and curling.

6. Intervals between coats are critical, consult manufacture. Ensure relevant information is written into specification.

G1

Offsite:


85

20

Not applicable

See notes under G1


See notes under G1

AS2/ZS1


150

20 Not applicable

See notes under AS1/ZS1 As noted in G1 above

See notes under AS1/ZS1

Table 2 Environment G: Typical Protective Systems

Polluted Coastal Dry film thickness m

Cost comp




(a) (b)



P6

Off site:

Blast to Sa 2, EN 8501-1




Coat 3 Two-pack Chemical Resistant Undercoat

Onsite:

Rectify transit/erection damage with

15

75

125

(75)


2. This coat can be omitted if post fabrication blasting is carried out.


4. Consult manufacturer for min temperature and max humidity requirements during application and 'curling'.

Prepare and apply one to two coats of coat 4 type Two-pack Chemical Resistant Finish.

OR

one-pack moisture curing polyurethanes

Preparation may include light blasting. Remember, temperature and humidity and intervals between coats are critical. Refurbishing with a One-pack Chemical Resistant Finish can be

Coat 2 Primer, bring forward primed areas with coat 3 type undercoat.

Coat 4 two-pack Chemical Resistant Finish

Total DFT

OR

substitute Coat 4 One-pack Chemical Resistant Finish

Alternative process Total DFT

(125)

75

275

75

275

10+

10+

10

7-12

5. Interval between coats is critical consult manufacturer. Ensure relevant information is written into specification.

6. This is a useful alternative to a 2-pack paint as the final coat under cold conditions or where there are likely to be delays on site (includes 1-pack moisture-curling polyurethanes)

7. Glossy 1 or 2 pack Chemical Resistant Finishes will give lower DFT's (circa 25 m).

OR

Prepare and apply one or two coats One-pack Chemical Resistant Finish.

considered i.e. chlorinated rubber, vinyl or acrylic resin based. Also 1-pack moisture-curing urethane.

Table 2 Environment G: Typical Protective Systems

Polluted Coastal Dry film thickness m

Cost comp




(a) (b)



P8

Off site:

Blast to Medium Profile ISO 8503 Part 1



On site:

Rectify transit/erection damage with 2 coats One-pack Chemical Resistant Primer.



15

100

(50)

(50)

75

75

75





Prepare, prime with One-pack Chemical Resistant Primer, bring forward with one coat of Coat 3 type undercoat and apply Coat 4 type finish overall (1 or 2 coats).


Finish


Total DFT

Replacing with full gloss One-pack Chemical Resistant Finish gives 25 m for final coat:

Total DFT becomes

325

275(6)

15+

10+

12

10




G1

Offsite:


140

10+

Not applicable

See notes under G1


See notes under G1

AS2/ZS2


150

15+ Not applicable

See notes under AS1/ZS1 As noted in G1 above

See notes under AS1/ZS1

Documents

L 4A_2b Tab of Factor