Construction Notes for a Steel String Guitar Preface

1

CONSTRUCTION NOTESfor a

STEEL STRING GUITAR

by

Denny Brown

Foreword by Robert O’Brien

Binder Spine Label

Print this page, cut out the labeland place in a binder spine

Cover: Steel String Rosette Inlay by Denny Brown

Photo credit: Denny Brown

© Dennistoun Brown 2012

Construction Notes for a Steel String Guitar Preface

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STE

EL ST

RING

GU

ITAR

Preface

Construction Notes for a Steel String Guitar is a conversion of my notes into detailed building instructions for a 25.4 inch scale length steel string guitar. Like its companion, Construction Notes for a Classical Guitar, it is based on study under Robert O’Brien, while he directed the Red Rocks Community College Lutherie Program in Denver, Colorado. The original audience was students in Robert’s classes. However, with the release of his “Online Acoustic Guitar Building Course” in 2012, the first version was rewritten for the benefit of online students, as well.

Greatest credit for this handbook goes to Robert O’Brien, who in 2003 founded and, until 2012, directed the Lutherie Program at Red Rocks Community College in Denver, CO. This is primarily a tabulation of his teachings. Other information in Construction Notes for a Steel String Guitar comes from a variety of sources. I am indebted to fellow teaching assistants, Mike Boggess (www.treesongguitars.com), Jim Mcmurdo and Karen Kemerling (www.k2guitars.com), who have guided my guitar building and, remarkably, have kept me out of trouble. Their wisdom is greatly appreciated. Many of their tips are found in this handbook. The rest, which really doesn’t seem to leave much, I learned on my own through a combination of technical successes, a few “design opportunities,” i.e. mistakes, and outside reading.

Robert O’Brien, to date, has supervised the building of over 500 guitars by students in Colorado, from teenagers to retirees. Several of his students relocated to Colorado specifically to take one or more of his courses.

Robert’s commitment to teaching is known internationally. The DVDs that Robert made for his early students have guided thousands of guitar builders who have purchased guitar kits from LMI, Int’l. More recently, Robert’s “Online Classical Guitar Building Course” and “Online Acoustic Guitar Building Course” were released, which display his ability to distill the complexities and mysteries of guitar making into logical steps. Besides his personal and professional commitments, Robert finds the time to host and actively participate in a Google Chat Group on guitar building. Participants hail from the U.S., Canada, Europe, South America, Australia and Asia. You are invited to join his group at www.groups.google.com/group/obrien-forum.

Construction Notes for a Steel String Guitar Preface

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None of this is to say that Robert has made guitar making easy. It is not, and it probably never will be. However, he has given many people worldwide the confidence to take the risk to do what for them had only been a dream.

Denny Brown

Boulder, CO

Construction Notes for a Steel String Guitar Preface

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Introduction

While these notes are based on several sources, they distill down to one of many ways to build a steel string guitar. Indeed, every luthier has his or her own method to make a guitar. With so many steps, variations quickly develop. Nonetheless, what I have recorded closely follows the current methods used by Robert O'Brien.

Experienced builders can use Construction Notes for a Steel String Guitar alone as a reference to refresh his or her memory on the steps of building, or to see another way to do things. For the first-time guitar maker, this handbook alone may be inadequate as a guide to building a steel string guitar. Some things just have to be seen once or twice before they make sense.

The materials and dimensions used in this handbook are based on the LMI (Luthiers Mercantile, Int’l ) KLSRO kit, used in Robert’s classes and in his online course. However, this does not preclude the use of materials from numerous other quality luthier sources.

Construction Notes for a Steel String Guitar can also be paired with Robert’s DVDs and his free YouTube “Luthier Tips du Jour” series. Several books and videos are available from other reputable authors. However, all of these resources differ to some degree from this handbook. In the case of Robert’s DVDs, certain sections are dated. When there is a disagreement between the DVD and these notes, the methods here are most current.

For convenience, hyperlinks are provided within the text to “Luthier Tips du Jour” episodes and to each “Online Classical Guitar Building Course” lesson. The Table of Contents also links to respective sections in the handbook.

The best learning experience, of course, is to build your guitar with Robert O’Brien in Colorado. For those who cannot, his "Online Steel String Guitar Building Course” is a remarkably close second best option. It is every bit as detailed as his classes, perhaps more so.

Construction Notes for a Steel String Guitar   Introduction

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You may print this manual. Use it to take notes. Lots of notes. The true discovery of great things in your guitar will happen over 250 pages from here when you first put on the strings. No sooner. If your guitar is a home run, wouldn’t you like to have some clues how it happened? On the other hand, if your guitar doesn’t come out the way you wanted, wouldn’t you also want to know why? Take notes.

When you are ready to build a classical guitar, be sure to take a look at Robert O’Brien’s “Online Classical Guitar Building Course”, and the companion handbook, Construction Notes for a Classical Guitar.

Input for Construction Notes for a Steel String Guitar is welcome. Write to me at FlatironFrets@Gmail.com.

A word of caution

Several steps of building a guitar are dangerous, including those using hand tools. It is the reader’s responsibility to learn how to use

and maintain equipment safely and correctly.

This is not a safety manual.

Construction Notes for a Steel String Guitar Introduction

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Foreword  Denny Brown’s Construction Notes series for guitar building is the set of books I had planned to write for my students, but somehow I never got around to actually doing it.  With a young family and a growing lutherie program, this task never managed to move to the top of my “To Do” list.   I was thrilled when Denny unexpectedly presented his first book on the classical guitar to me in December of 2011. I immediately asked to use it in my classroom and hoped he would write a steel string version, too.  (Obviously, he did.)  Actually, I think that I was not only thrilled, but relieved that this long overdue project was finally complete. Denny went above and beyond what I had envisioned and created an interactive manual. Students have instant access to my online courses and Luthier Tips du Jour videos just by clicking on the active links throughout the text. Since Denny introduced these texts, my students’ work has improved significantly.  Students now have a written study guide that allows them to prepare for class ahead of time.  In the shop, they have a detailed checklist to minimize mistakes. And as importantly, they have a place to record notes on their progress.  As an instructor, these books have made my life easier and helped my students build better guitars. Denny has meticulously captured how I build guitars.  He also offers some additional perspective, which is a bonus for the user.  These handbooks have become an indispensable part of my teaching and are now required reading for students in my workshop.   Using these books will make your guitar-building experience more rewarding and easier than ever, leading to the result you want: a guitar that both looks and sounds beautiful.   Robert O’BrienParker, Coloradowww.obrienguitars.com

Construction Notes for a Steel String Guitar   Foreword

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About the Author

Denny Brown discovered fine woodworking in 2007 after retiring from a career as a general surgeon. He found one of the premier woodworking programs in the United States just forty-five minutes from home. His passion for fine craftsmanship and detail led him to Robert O’Brien’s guitar-making classes. Denny builds both steel string and classical guitars. He is a teaching assistant for O’Brien’s guitar building classes in Denver, Colorado. He is also the author of Construction Notes for a Classical String Guitar and writes the “My Guitar Notes” blog at www.flatironfrets.com. Denny lives in Boulder, Colorado with his wife and children.

Construction Notes for a Steel String Guitar   Forward

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Table of Contents

Chapter 1: Sides 11

................................................................................Dimension the Sides 11

Joint the Sides 11

Cut the Sides to Width 11

Safe-T-Planer Set Up 12

Thickness the Sides 12

Set Up for Bending 13

Make a Side Template 14

Layout and Taper the Sides 15

...........................................................................................Crack Repair 16

........................................................................................Bend the Sides 17

Super Soft 17

Set up 17

Bending with a Thermocouple 19

Placing the Side in the Guitar Form 19

.............................................................................Heel and End Blocks 20

Construction Notes for a Steel String Guitar   Table of Contents

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Prep the End Block 20

Prep the Heel Block 21

Cut Sides to Length 21

Glue the Sides to the End and Heel Blocks 22

................................................................................Clean Up the Sides 23

...............................................................................................Radiusing 24

Radius the Top 24

Radius the Back 25

...................................................................................Install the Kerfing 26

Shape the Kerfing 27

Glue up 27

.....................................................................................................Struts 28

.............................................................................................End Wedge 29

Make the End Wedge 29

Cut a Wedge in the Body 30

Glue Up the End Wedge 31

Construction Notes for a Steel String Guitar Table of Contents

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Chapter 1: Sides

• See “Online Acoustic Guitar Building Course”:o Intro (free)o The LMI Kit (free)o Relative Humidity (free)

Dimension the Sides• See “Online Acoustic Guitar Building Course”: Cutting Sides to Width• See “Luthier Tips du Jour”: Band Saws

Joint the Sideso Bookmatch the two sides and fold together

§ Bookmatching is placing the two sides beside each other in a mirror image format, left to right

o Look at the grain figure and consider what edge will be at the top of the guitar and what edge will be at the back

§ Account for the back edge of the upper bout being cut away slightly in a taper• See Make a Side Template, below

o Select the edge that will be the top of the guitar sides to joint

§ Tape the opposite edges together with two pieces of tapeo Joint the top edge

Cut the Sides to Widtho Rip the sides to 110 - 115 mm in width with the band saw, cutting off the

taped side

Construction Notes for a Steel String Guitar Chapter 1: Sides

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Safe-T-Planer Set Up• See “Online Acoustic Guitar Building Course”: Thicknessing• See “Luthier Tips du Jour”: Safe-T-Planer

• Note: In 2012, production of the Safe-T-Planer was discontinued. A similar product is the Drill Press Planer

o Put Safe-T-Planer in the drill presso Tilt the table very slightly downhill so the exit side of cutter is wider than

the entry

§ A folded piece of sandpaper under the in-feed side of the table is enough

o Set the depth to 2.7 mmo Set the drill press speed to 2000-2500 RPM

o Make sure the table is clean so the board is not lifted by debris and cut too thin

o Test cut

§ Feed a piece of scrap under the Safe-T-Planer and measure the thickness of the cut

§ Adjust table as needed and redo test cuts until correct

Thickness the Sides• See “Online Acoustic Guitar Building Course”:

o Scrapingo Sanding

• Book match the sides and select paired surfaces to planeo Plane the less desired side since it may reveal a surprise o Do a test cut at the beginning of each side

• This is best done with two people, one pushing the side in and the other pulling it outo Hold sides down with smooth blocks at entry and exit of planer head

§ This prevents lifting the side and getting it too thin

Construction Notes for a Steel String Guitar Chapter 1: Sides

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o With one person, push the board in as far as possible using a hold down block, then pull the board through with a hold down block on the out-feed side

• Final thicknessing options

o Thickness Sander (preferred)o Scrapero Hand sandero See “Luthier Tips du Jour”:

§ Scrapers

§ Thickness Sanding Sides

• Thickness sander

o The target point is 2.2 mm and flexibility suitable for bending (a good indicator is the beginning of flex transversely)

§ Measure the thickness of sides, tops and backs with a dial caliper

o Send sides through sander at 30o angle to avoid overheating the sanding belt

o A single pass without changing the setting may be all that is needed to fine-tune the thickness

o Measured final thickness of sides = ______ mm

• Consider thicknessing the back pieces now while the Safe-T-Planer is set up, see Chapter 3: Back

Set Up for Bending • See “Online Acoustic Guitar Building Course”:

o Moldso Intro to Bending

Construction Notes for a Steel String Guitar Chapter 1: Sides

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Make a Side Template• See “Online Acoustic Guitar Building Course”: Tapering the Sides

• Considerationso The markup measurements can also used directly on the sides without

making a template

o Use anything thin, such as paper, plastic, ¼” MDF or fiberboard• Dimensions

o Cut a piece of material

§ 80 cm long

§ 11 cm (110 mm) tall

46 cmO cm 74 cm

TOP

BACKNE

CK

BU

TT

↓ Taper ↓

WA

IST

↓ “End Line” ↓ “End Line”

95 mm110 mm

o Mark up

§ Measure 3 cm in from both ends and draw square lines (“end lines”)

• The distance between these two line should be 74 cmo For a mark up directly on the guitar, use this length

and position the space over the most desirable part of the sides

§ From one of the end lines, measure in 46 cm and square a line• Label this line “WAIST”

§ Label the end line NEAREST the waist “NECK”

§ Label the end line FARTHEST from the waist “BUTT”o Taper cut

§ On the NECK end line, mark 95 mm from one edge

§ Draw a straight line from this mark to the end of the nearest waist line• Band saw this line and discard the cutoff

o Label the template

Construction Notes for a Steel String Guitar Chapter 1: Sides

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§ Along the side with the tapered side, mark “BACK”

§ Along the uncut straight edge, mark “TOP”• Do not get these backwards!

§ Label the template “STEEL STRING”, in case you later make classical guitars

o Transfer all of the labels and lines to the opposite side

o Cut ¼” notches at the ends of the each line to aid marking the

Layout and Taper the Sides• Bookmatch the sides and lay the two pieces side by side • Select the desired outside surfaces• Fold the sides together with the desired outside surfaces on the outside of the

sandwich• Mark the layout orientation

o Use white pencil on the outside of both pieceso Select and mark the neck and butt ends

§ Remember that the neck end will be tapered o Mark the jointed edges as the topo Align the side template on the sides so the top edge is flush against the

top (jointed) edgeo Use the side template to mark locations of the waist, neck end and butt

ends

§ Mark the waist on the edge, tooo Mark the front taper

§ Mark inside the taper line with an “X”, so the mark remains after the taper is cut

• Band saw the taper

Construction Notes for a Steel String Guitar Chapter 1: Sides

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Crack Repair• See “Online Acoustic Guitar Building Course”: Crack Repair

• Cracks can and will occur, particularly in the sides• Most cracks are 50 mm, or less, but they can also be very dramatic• The rescue is frequently CA glue, plus accelerator• Dark wood cracks, especially with the grain, tend to hide well• Do NOT use CA glue for tops

o Light colored woods stain with CA glue

• In all cases, the principle is to get the wood on either side of the crack lined up and held in place while glue sets

• Another pair of hands might be handy, if using CA glue with accelerator

• Minor Fixes

§ Get the wood lined up

§ Let thin CA glue flow into the crack

§ Apply accelerator and hold until set

• Major Fixes - for example, a long split in the sideo Identify the length of the crack and mark each endo Get the two sides lined up precisely, whatever it takes

§ This is criticalo Let thin CA glue flow generously into the crack along its entire length

§ If the cracks is clamped, sand over the crack with old sandpaper to fill irregularities in the crack

§ If the crack is being held by hand, apply acceleratoro Repeat on the other sideo Scrape and sand smooth

Construction Notes for a Steel String Guitar Chapter 1: Sides

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Bend the Sides• See “Online Acoustic Guitar Building Course”:

o Bending, Part 1o Bending, Part 2

• See “Luthier Tips du Jour”:o LMI Side Bender o Side Bending by Hand o Making Forms

Super Soft • An optional step• Spray the sides with Super Soft, as instructed on the bottle• Let dry between paper under a weight overnight

Set up• Obtain or make a guitar form for your plan• Set up bending machine with the correct bending profile• Lay the guitar form on the bench in line with the bender, i.e. neck end in the same

direction as the bending machine is set up• Mark the up side of the guitar form “BACK”, and the other side “TOP” using

tape• Lay the sides on top of the guitar form on the table with the outsides up, the

back edges to the center and the neck /butt oriented in the same direction as the form and bending machine

Construction Notes for a Steel String Guitar Chapter 1: Sides

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• Position the woodo Put the first sheet of spring steel in the bending machine

§ Line up the spring steel parallel to one side of the bending formo Spray wood lightly with watero Put one guitar side outside up on the spring steel and line up the top

(jointed) edge parallel to the edge of the spring steelo Position the waistline of the guitar side in the center of the bending

machine

§ Add the heating pad, then the second sheet of spring steel

§ Double check positioning

§ Spring-clip the sandwich together• When bending

o Do not walk away from the bending machineo Avoid distractions such as conversations, telephoneso Heating moves very fast and can quickly lead to a disaster

Bending with a Thermometer • There are several bending routines that work well, this is just one• Tighten the waist clamp just enough to flex the wood and hold it in place• Put handles on springs• Place a thermometer between the heating pad and the spring steel sheet

o Make sure the thermometer is set on FAHRENHEIT• Connect the heating blanket to the timer and turn on the timer

o Heat to 200-250o Fo Bend the waist fullyo Slowly bend the large bout then the small bout

§ Watch temperatureo There are several ways to finish the heating process

§ 1. Heat to 300o - 325o F and hold there for 5 minutes by turning the power on and off

§ 2. Heat to 325o - 350o F and turn the heating pad of fas soon as up to temperature

§ 3. Heat to 325o - 350o F, cool, then reheat to 325o - 350o F, then cool

Construction Notes for a Steel String Guitar Chapter 1: Sides

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• Cool and remove the side• Place the side in the guitar form

Bending with a Thermocouple • See “Luthier Tips du Jour”: Heating Blanket Temperature Controller

• This uses a specialized piece of equipment• Tighten the waist clamp just enough to flex the wood and hold it in place• Put handles on springs• Place the thermocouple probe between the heating pad and the wood

• Set thermostat to 300o F• Heat to 200-250o F• Bend waist• Slowly bend the large bout then the small bout

• Hold at 300o - 325o F for 5 minuteso (Optional) leave side in the bender at 260o F for 15 minutes

• Cool and remove side• Place the side in the guitar form

Placing the Side in the Guitar Formo Place the bent side in the form top side down, flush with the table topo Insert the spreadero Apply cam clamps where there are gaps

• Bend the second sideo Double check side orientationo Bend second side, just like firsto Insert in formo Mark orientation

§ Use tape to mark L/R, top and back on the sides• This can’t be over done

Construction Notes for a Steel String Guitar Chapter 1: Sides

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Heel and End Blocks• See “Online Acoustic Guitar Building Course”: Heel and End Blocks

• See “Luthier Tips du Jour”:o Heel and End Blocks o Hand Planeso Sharpening

Prep the End Block• Orient the grain horizontally• Band saw the block to these dimensions

o 76 mm (wide)

o 21 mm (thick)

o 108 mm (tall)• Sand the rough sides of the block and bring them close to final dimensions

o Finished dimensions will be 76 x 19 x 102 mmo The ends of the block do not need to be sanded

§ The height of the block will be brought to size when the guitar is radiused later in this chapter

o Plane a bevel on the two vertical corners that will be on the inside of the guitar

§ This is cosmetic, be careful of blow outo Mark centerlines on both ends of the blocko Remove the sides from the formo Slide the end of the guitar form off of the bencho Place the block beneath the tail end of the empty guitar form, line up the

centerline and trace the contour for planing

§ Plane the block to fit flush inside of the form• The line is for reference so that the contour can be planed

parallel to it• Don’t round corners and be careful of blowout

§ Check fit, sliding the block up and down in the form to look for gaps

§ Sand to 180 grit

Construction Notes for a Steel String Guitar Chapter 1: Sides

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Prep the Heel Block• Orient grain horizontally• Band saw the block to these dimensions

o 70 mm (wide)

o 34 mm (thick)

o 88 mm (tall)• Sand the rough sides of the block and bring them close to final dimensions

o Finished dimensions are 70 x 32 x 82 mmo The finished thickness MUST BE 32 mm for the neck bolts to fit

§ A little less is okay, more is noto The ends of the block do not need to be sanded

§ The height of the block will be brought to size when the guitar is radiused later in this chapter

o Plane a bevel on the two vertical corners that will be on the inside of the guitar

§ This is cosmetic, be careful of blow outo Mark centerlines on both ends of the block

Cut Sides to Length• See “Online Acoustic Guitar Building Course”: Cutting the Sides to Length

• Place one of the sides, top side down in the form• Insert the spreader• Cam clamp the side to the form to eliminate gaps around the bouts• Push sides down flush against the table• Mark the centerline

o On the side, mark the centerline with white pencil at each end using the form centerline

o Remove the side from the guitar formo With a square, transfer these lines to the inside of the guitar side, making

sure to square off of the top (flat) edgeo Repeat with the other side

• Cut

Construction Notes for a Steel String Guitar Chapter 1: Sides

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o Band saw the sides just short of the lines

§ Save cutoffs for caulso Finish to the line with a sandero Replace sides in the guitar form in the correct orientationo Reinsert the spreadero Clamp sides to the guitar form to eliminate gaps around the lower bout

Glue the Sides to the End and Heel Blocks• See “Online Acoustic Guitar Building Course”: Gluing Sides to Blocks• See “Luthier Tips du Jour”:

o Glues Part 1 o Glues Part 2

• Sand the inside of the sides to 180 grit where the end block will be glued, plus

5 cm to either side

• Toolso 8 - C-clampso 4 - Cam clampso Spring clampo Wax papero Rosewood cutoffs for cauls (from the last step)

o If there aren’t enough clamps, or a more relaxed two-step pace is preferred, only half as many clamps are needed

• Set upo Be sure the guitar form is top side down on the bencho Mark the centerline on both ends of the blocks and on the glue faces

§ Put the blocks at the correct ends of the guitar formo Make sure the sides of the blocks are square to the bench

Construction Notes for a Steel String Guitar Chapter 1: Sides

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• Glue upo Set up the clamps with a dry run, this has to move quickly if both ends are

being done simultaneously

o Place wax paper on the bench under where the blocks will be o Apply glue to the correct face (marked midline) of either blocko Position the block flush with the bencho Align the centerline with the form using the marked lineso Clamp sequence

§ Use wax paper beneath the outer cauls, if needed

§ Clamp one corner with a spring clamp to hold the cauls• Watch for skating of the end block

§ Clamp both back corners firmly, removing the spring the clamp after the first C-clamp is applied• Position clamps towards the outside of the block for a flush

fit

§ Check the block for square to the bench

§ Repeat this sequence with the other block

§ Remove the sides from the form

§ Use a spring clamp to hole the cauls in place

§ Add clamps to the top corners of both blocks

§ Clean glue squeeze out

§ Add two cam clamps to the center of each block

• 20-30 minutes clamp time

Clean Up the Sides• Scrape and sand the inner surfaces of the sides to 180 grit

Construction Notes for a Steel String Guitar Chapter 1: Sides

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Radiusing• See “Online Acoustic Guitar Building Course”: Radiusing• See “Luthier Tips du Jour”: Closing the Box

• Radiusing is putting a curvature on the top and back of the guitar to create slight domes in the top and back when are glued to the bodyo It is very easy to become disoriented and make mistakes in this process

o Pay attention to having the dish with the proper radius (15’ or 30’) and working on the correct side (top or back) of the guitar.

• Authors Note: I radius the top first and the back second, the reverse of Robert’s method. I find it keeps me out of trouble. The end and heel block heights will need to be finalized while radiusing. This should be done from the back side. I find that if I radius the back first, I am tempted to make any final height adjustments from the top, since the back is already finished. Making adjustments from the front risks taking the top edge out of parallel with the grain figure on the sides. There is a significant taper on the back upper bout of the back, so parallel grain is not expected there. This is purely cosmetic, so it is of no functional importance.

Radius the Top• Take out a 30‘radius dish with sandpaper

o Clamp the dish to the bench with cam clamps, leaving room for sanding

• Turn the form TOP SIDE DOWN and put pieces of blue tape around the back edgeso Anything that keeps things oriented is good o When radiusing, the blue tape should be up

• Put the guitar TOP SIDE DOWN in the radius dish and assess for gaps• Turn the form over and plane down the proud points on the top side

o Plane towards the heel block to avoid splitting• Recheck for gaps

o Repeat planing until the sides are close to the desired radius of the dish

Construction Notes for a Steel String Guitar Chapter 1: Sides

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• Sand in the 30’ radius dish with a twisting motion

o Use chalk on the side edges and the produced sawdust in the dish for a guide in sanding, until there is no gap

o Additional planing can be used gingerly to speed the process

• If desired, kerfing can be added to the top, now, and the back radiused after the glue has dried

Radius the Back

• Put away the 30’ radius dish

• Take out a 15’ radius dish with sandpaper • Clamp the dish to the bench with cam clamps, leaving room for sanding

• Put the form TOP SIDE DOWN on the bench and be sure the top of the guitar lies flat o With a white pencil, mark in three places on the sides where they meet the

form, for reference if the guitar slips in the form and needs repositioning

• Turn the form BACK SIDE DOWN and put pieces of blue tape around the top edgeso Anything that keeps things oriented is good o When radiusing, the blue tape should be up

• Turn the form BACK SIDE UP• Plane the block height down to near the target heights

o Target heights:

§ Heel block 80 mm

§ End block 100-105 mm o Tilt the plane angled up towards the center of the guitar a little to

accommodate for the 30’ radius

• Put the guitar onto the radius dish BACK SIDE DOWN

Construction Notes for a Steel String Guitar Chapter 1: Sides

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o Make sure there is enough of the sides protruding from the form in back to radius without inadvertently sanding the form

o Wrap fingers around the form

§ If they touch the sandpaper, adjust the form higher

§ If an adjustment has been made, flip the body top side down and be sure the edges are flush with the table top

• Put the guitar BACK SIDE DOWN in the radius dish and assess for gaps• Turn the form over and plane down the proud points

o Plane towards the heel block to avoid splitting• Recheck for gaps

o Repeat planing until the sides are close to the desired radius of the dish

• Sand in the 15’ radius dish with a twisting motion

o Use chalk on the side edges and the produced sawdust for a guide in sanding, until there is no gap

o Additional planing can be used gingerly to speed the process

Install the Kerfing• See “Online Acoustic Guitar Building Course”:

o Kerfing o More radiusing and Kerfing

• See “Luthier Tips du Jour”: Kerfing

• The kerfing will be the glue surface for the top and the back

• Be sure the inside is sanded to 180 grit• Do top side first

o Actually, this doesn’t matter, but the top can be seen as practice run, since mistakes will be hidden

• Check that the sides are square to the bench in the form• Kerfing clamps are glorified clothes pins with rubber bands around their arms to

add more closure forceo Commercial kerfing clamps are available from LMI

Construction Notes for a Steel String Guitar Chapter 1: Sides

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Shape the Kerfing• Wet kerfing and let outer surface dry• Clamp kerfing to the outside of the body with a few kerfing clamps and let dry

o Make sure the kerfing is oriented correctlyo With reverse kerfing, the flat side of the kerfing will be against the outside

surface of the side

Glue up• Break off the kerfing to about the amount that is needed• Lay the kerfing on a flat surface and apply glue to entire strip, blot, don’t spread

• Position the kerfing 1-2mm proud of the side edge • Begin at the heel block (front) and get as flush to the block as possible• Bunch kerfing together if it breaks • Apply kerfing clips flush next to each other as you go

o Lean clips forward into the body interior• After the left and right strips are applied, apply 4 cam clamps to the corners of

the form with arms up, then flip the form onto the armso Alternatively, clamp the form upright in a bench vise

• Remove the spreader and inspect the kerfing for gaps • Adjust clips or add small spring clamps where the kerfing is not flush with the

sides• Let glue set up a bit and scrape gross glue squeeze out• Clean kerfing gaps with a razor blade

• Clamp time: 30-45 minutes

• If desired, kerfing for the other side can be shaped while the glue dries on the first sideo Turn the cam clamps facing the other way and turn the other side upo Reinsert the spreadero Shape the kerfing as was done on the first sideo Continue with the glue up after kerfing clamps have been removed from the

first side

Construction Notes for a Steel String Guitar Chapter 1: Sides

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• Otherwise, shape the kerfing and do the glue up exactly as was done on the first side

• Sand kerfing to 180 grit• Touch up any sanding on the inside

Struts• See “Online Acoustic Guitar Building Course”: Side Struts

• Struts are strips of wood that are glued to the sides vertically between the kerfingo They are decorative, structural and, perhaps, tonal

§ They will help limit the length of a split in the side, should one occur

§ The struts further stiffen the sides and may help project tone• Struts can be made from scrap wood, such as cut offs of back and brace wood

o Some builders make immaculate laminated strips of various woods to add to the decorative value

• Use three to four strutso One on the upper bout, one behind the waist and one or two in the lower

bout

• Make the struts 2.5 - 6 mm thick

o Thicker strips can be scalloped or tapered on the ends to transition down to the kerfing

• Position the struts symmetrically from left to righto To be precise, count kerfing spaces along the sideo Mark the locations

• Cut each piece a little long• Fit each piece between the kerfing using a sander to adjust the angles of the ends

o Mark each piece with its location on a piece of tapeo Square the end that will be at the topo Put the strut in place on the guitar side and estimate the angle needed to

be cut offo Sand the angle and adjust it until it fits

• Glue upo Apply glue to the struts, less is more

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o Position them straight up and down

§ Use a square from the top, if desiredo Clamp in place with spring clampso Watch for skatingo Clean the squeeze out

o Clamp time 30 minutes

End Wedge• See “Online Acoustic Guitar Building Course”: End Wedge• See “Luthier Tips du Jour”: End Grafts

Make the End Wedge• Select a piece of wood long and wide enough for the end wedge with plenty of

extra lengtho A piece of curly maple is often used

§ Even a scrap piece of the rosewood back works very wello Select a bevel angle that looks good and set it on a sliding bevel o Mark a centerline on the back side of the end wedge, extending full length

§ Optionally cover the wood with tape and put the markings on the tape

o Decide how wide the graft is going to beo Mark symmetrical lines on the wood piece on both sides of the centerline,

using the sliding bevelo Make sure the end graft piece is longer than needed o Band saw out the end graft wedge with a small extra margin outside the lineo True the edge with a plane on a shooting board

§ Plane from the wide to the narrow end

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Cut a Wedge in the Body• Remove the guitar body from the form • Mark the centerline on both ends of the end block

o Apply masking tape over the end block to facilitate marking• Orient end wedge up or down, it doesn’t matter• Place the end wedge with the centerline face down to line up with the centerline

marks on the end block• Hold the end wedge tightly in place or with spring clamps, or use an extra pair of

hands • Mark the outline of the wedge on the guitar body

• Hang the guitar body on a board suspended from a bench• Use a block of wood with a square edge as a saw fence • Position the block on a triple-folded-over piece of sandpaper just outside of one

of the marked lines and clamp it in place• Saw on the marked line only through the side wood

o The sawdust will change color as soon as the side wood is fully cut• Repeat on the other side• Chisel out the side wood, checking the graft fit• Flatten rough spots on the exposed end block

• An alternative method for cutting, which is particularly useful for curved end pieces:

o Hold the end wedge tightly in place or with spring clamps, or use an extra pair of hands

o Scribe around the outline of the wedge on the guitar bodyo Use a Dremel tool and a downcut spiral bit

§ Rout close to the lineo Finish with a chisel

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Glue Up the End Wedgeo Place glue on the back and sides of the graft and on any veneer accents

being used o Slide the end graft and veneers snuggly into place o Spring clamp both endso 20-30 minute clamp time

o After the clamps are off, band saw or hand saw the excess offo Plane/scrape the end wedge flush with the bodyo Return the body to the form making sure the top is flat to a bench

Notes:

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