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With the finish polished to it’s final gloss it was finally time to bring the guitar to life by adding the bridge, saddle, nut, tuners and strings… Oh yeah, can’t forget a pretty label.

Immediately after polishing I roughened up the area that was masked off previously for the bridge with some 80 grit sandpaper.  Two bridge pins will be used to index the bridge while being glued to the soundboard. The bridge was set in it’s final position and the 1st and 6th bridge pin holes were drilled out.  Wood glue was applied liberally to the bridge and the soundboard and put in position.  The bridge pins were wrapped with masking tape and reinserted.  The bridge as then clamped in place using a long-reach clamp, a shaped caul and some wedges.  Any glue squeeze-out was removed from the bridge and the lacquer using a damp paper towel and left to dry.

That night I also trimmed the nut, made by Tusq out of a high-density plastic in lieu of bone, and glued it in place.  It’s the same material used on my Taylor.  I also fitted the clear Mylar pick guard and installed the Gotoh 503 chrome tuning machines on the headstock.

The next morning I pulled the clamps, drilled out the remaining bridge pin holes and worked on shaping the saddle.  The saddle blank is also made by Tusq.  It had to be thinned slightly to fit in the slot on the bridge.  I was reduced in height slightly and the string compensation profile was filed into the top of the saddle.  The books covered this important and delicate process very well including the why and the how.

Now to shape the nut.  With the saddle shaped I fitted the 1st and 6th strings loosely and marked their locations on the nut.  The middle four strings are evenly distributed between the outer two.  The slots for the strings were then cut with small saws and needle files to their rough width and depth.  The strings were brought up to tension and the action was gauged at the nut.  Each string was pressed down between the 2nd and 3rd frets and the height over the 1st fret was noted.  The strings were loosened and the depth of the slot was reduced until that noted height was about 0.1mm.  Any lower and the string will buzz when played open.  The nut was dressed to height and shaped with files and some dry 1200 grit sandpaper.

All that’s left was install the interior label and play a few songs… to make sure it sounded OK.  I decided on “Puff the Magic Dragon” for my girls…  It’s definitely a quieter guitar than my Taylor dreadnought and isn’t as “boomy.”  It has a pleasant if fairly bright sound that will mellow and get fuller as it ages. It’s a very comfortable size to hold in your lap.

96.00 hours from start to finish of actual construction time.  Overall I’m very happy with how it came out. Joan and Steve will see/hear it for the first time at their Christmas on Saturday.

Below is the complete gallery with all 100 images of the build.  I’ll post a full gallery of Beauty Shots soon.

2008. 12 Guitar - Beauty Shots

Final photos of the cherry bodied, Engelmann spruce topped guitar build for Joan for Christmas.

21 Photos

2008.12 Guitar - Construction

Photos taken during the construction of a cherry guitar.

100 Photos

Time for the stuff that really gives a project life and can cause hours of aggravation: the finish.  There are two major options for finishing a wood guitar: a clear film finish (traditionally varnish or lacquer) or oil.  Oil finishes are super easy to apply.  You just wipe on 10-12 coats of oil, letting it dry overnight between coats.  The surface of the wood has to be perfect though because the oil will enhance every missed sanding scratch.  Oil doesn’t give the guitar much protection either.  A film finish is much tougher.  It was mainly for this reason I chose lacquer.  I chose a water-borne lacquer called KTM-9 that came highly regarded by other home luthiers.  Before I could spray on the lacquer I needed to do some prep work…

First I had to install and dress all the frets.  It sounded all a bit nerve-wracking at first but ended up being a fairly straightforward operation. Fret wire (medium height – medium width) comes in 18″ long sections.  The barbed tang gets hammered into the slots in the fingerboard and should be enough for a permanent installation.  My books both recommended putting a few drops of wood glue in each slot.. just in case.  The frets were trimmed flush with a nippers and filed even with the fingerboard.  The frets are never perfectly level so they get sanded even and then shaped back with a fine triangular file.  Then they and the ebony fingerboard get polished using sandpaper, starting with P400 grit and working up to P1200.

The trench for the nut was cut and then everything, except for the polished fingerboard, was sanded to P240.  To prevent splotching, the softer top was further sanded to P320.  The top of the fingerboard, the location of the bridge and the soundhole were masked off with tape.  The entire guitar was then sealed with a very thin coat of marine epoxy… Yup, the material recommended by the maker of the KTM-9, Grafted Coatings, to fill the pores and seal the wood was my old friend two-part clear epoxy.  Yeah, I think I had a gallon or two of MAS on hand… I mixed up about an ounce, thickened it with some aerosil (fumed silica) and squeegeed on a very thin coating.  After it had cured overnight it was leveled with P400 dry sandpaper.

Traditionally a nitro-cellulose lacquer is used but the reducers are high in VOC’s and are quite nasty!  I went with a water-borne lacquer mainly because I could safely spray it in the shop without killing any one.  I set up an area to spray, hung the guitar on a wire hanger and sprayed on the first 6 coats of lacquer with my HVLP gun.  One coat was sprayed every hour. It was left to dry overnight and the next day was leveled with P400 dry paper and the last 4 coats were sprayed on.

This KTM-9 was interesting stuff.  It was thin like water.  It was very easy to spray on too much and have sags and drips.  You couldn’t spray on extremely light coats because they would dry too fast and not level out…  I got used to it after the 4th coat after increasing the air pressure slightly and dialing back the width of fan.  The gun really needed a smaller nozzle for better atomization… oh well. I knew it had to be wet-sanded and polished anyway which was the last operation.

Like most lacquers, this stuff shrinks like crazy when it cures.  They recommend letting it cure for a minimum of five days, two weeks if possible.  Christmas was coming fast so I brought up stairs into our office where it hung in a nice, warm room.  Last saturday, the 13th after hanging for five days, I brought it back in the shop and wet-sanded the lacquer level.  I started with P600 and worked up through P1200.  I then power-sanded it with a Festool S2000 pad on my RO125 sander which brought it up to a semi-gloss.  For the final high gloss I used felt pads loaded with Mequire’s automotive rubbing compounds.  I used #84 Power Compound, then #9 Swirl Remover and finished up with #3 Glaze and some silicone-free wax.   It looked like a mirror…

The final bit of finish work was to remove the masking tape and to oil the ebony fingerboard.  All that’s left now on this project is the final setup…

The sole purpose of the headstock is really just to hold the tuning machines.  It’s never flat with the fingerboard but angled at about 10 degrees so that the strings exert some pressure on the nut.  It can be virtually any size and shape.  Most built it with a fairly simple Martin or Gisbon style head shape.  I really liked the headstock designs of Tom Doerr in Florida who I got the wood sound-hole rosette idea from.  It had a nice asymmetrical shape that gave a lot of free space for the ebony and mother-of-pearl inlay of “Christy”. 

The headstock is an integral part of the neck.  It can be cut out of one large neck blank or scarfed on as a separate piece.  Scarfing solves some short-grain issues when cut out of a large blank but creates a joint.  If I scarfed mine, I’d lose some of the benefit of having continuous strips of carbon fiber.  But it’s because of the carbon I wasn’t worried about having short grain issues.  So I cut out my headstock to it’s rough thickness when I rough-cut the neck.

To further strengthen the headstock and unify the design I decided to laminate layers of veneer on either side.  Each side will have a 0.050″ thick show veneer of cherry followed by 0.020″ thick veneers of black walnut, maple, and black walnut.  The walnut-maple- walnut sandwich keeps the BWB theme I used in the binding.Before I could glue them on I had to thin down the headstock to it’s final thickness which is based on the length of the tuner shafts (about a 5/8″).  I smoothed the front face using sandpaper on a hard block and then thinned down the back using the beltsander and hand blocks.  I glued them on using regular wood glue, flat cauls and lots of c-clamps.  After the glue cured I tacked on a template of the headstock I had drafted on the computer, cut it out, sanded the edges smooth and drilled the holes for the tuners.

The inlays were next.  The first was Christy’s name at the top of the headstock in ebony.  The second was the big inlay of Christy based on a photo of her when she was 8 weeks old carrying a partidge wing.  I found a cool font for the first one called “Black Rose.”  I made a template on the computer and printed out three copies.  One I spray-glued on the headstock in it’s final position.  The second I glued to a piece of 0.050″ thick ebony.  The third was a spare…  I cut out the ebony by hand with my jeweler’s saw and a fine blade and routed out the headstock using my Dremel router and some small carbide bits.  The inlay was then glued in with epoxy and sanded it flush when cured.

The big inlay of Christy was done in a similar fashion:  I made a tracing of the photo and made 8 copies using a photocopier.  One copy I spray-glued to the headstock and taped on a piece of wax paper.   For each piece of ebony and shell I glued a paper copy to the ebony/shell stock and cut out each piece individually.  The individual pieced were then glued together in place on the wax paper.  When all the pieces were cut out and glued together I peeled the inlay from the wax paper, removed the tape and routed the rebate down to the thickness of the ebony and shells. I then epoxied on the inlay.  I sanded it flush with the headstock the next day.  Any pinholes and voids in the glue lines were filled with superglue and sanded flush.

The other inlays on the guitar are the dots on the front and side of the fingerboard.  They are pre-cut dots of green abalone that are installed by drilling a shallow hole, attaching with super glue and sanding level.  The side dots are 3/32″ while the fingerboard dots are 1/4″ and 5/16″.  These were the easiest inlays in the world…

All that’s left is finishing and setting up the guitar.  Getting close to the end…

The neck of a guitar is a pretty unique little piece of engineering.  About a quarter of the build time of the entire guitar went into some portion of the neck/headstock.  The neck has to be thick enough to withstand the stresses from the strings and not twist or bend.  Yet it has to be thin enough to be comfortable to play.  The neck also transmits some of the sound energy into the body, so the acoustic properties of the woods needs to be addressed.  It also needs to be adjustable down the road…  The fingerboard needs to be machined accurately so that the instrument plays in tune for it’s entire scale length.  The tolerances required are quite daunting.

Quarter-sawn Honduran mahogany and maple are the timbers traditionally used for steel string guitar necks.  Mahogany is tough to beat: It’s very stable.  Being even and straight grained and fairly soft it’s easy to carve into the complex curves of the neck.  It’s acoustically very sound as well.  Maple is stiffer and more stable, but tough to carve. To keep the woods similar on this guitar I decided to go with a laminated cherry neck to match the body.  Cherry also has mechanical properties that are similar to mahogany.  It’s not as stable though and may move with changes in humidity.  To help counteract this and stiffen it up I added a center spine of curly maple sandwiched by three layers of 5.5oz carbon fiber cloth on each side.  It also keeps with the black/white/black theme from the body binding.  I also used the best cherry I could find in my stack for the neck.  I used marine epoxy to laminate the neck.

After cleaning up any epoxy squeeze-out, I jointed the top surface straight and true on the jointer.  I’ll need to resharpen the blades soon: carbon fiber does a job on high-speed steel blades! I then cut the trench for the trussrod.  Virtually every guitar made in the last hundred years has a steel trussrod running down the spine of the neck.  They significantly stiffens the neck. Most are also adjustable and allow the neck to be put into tension or compression.  Put in compression it puts a reverse-curve in the neck and flattens it out. I used a dual-action one used in most Martin’s that is made by Gotoh.  I’ll glue it in later…

Traditionally the neck was attached to the top block of the body using a sliding dovetail joint.  Recently though most commercial builders have switched to a mortise and tenon joint that bolted together.  Two steel bolts run through the top block into meta inserts in the neck.  It greatly simplifies construction and is just as strong and acoustically similar.  It also allows easier removal of the neck if needed in the future.  I used the same system.  I cut the tenon in the neck and then rough cut the neck to shape.

The neck was then rough carved to shape using a straight spokeshave and my new rasp/file.  The file is pretty neat.  It’s cut so it takes a slicing cut.  It can be very aggressive like a wood rasp but leaves a very smooth finish like a file.  I guess they were originally made for working on aluminum car bodies. I heard about it through Lee Valley.  I modeled this neck on my Taylor’s.  I made cardboard cross sections of the neck at the 1st and 12th frets and carved the neck until was within a 1/16″.

The trussrod and the maple cap used to fill the remainder of the channel were glued in using epoxy.  I also drilled for and set the bolt inserts in the tenon.  To eliminate any chance of splitting, I drilled the holes for the inserts over-sized and set them with thickened epoxy.  I had drilled the holes in the top block before putting the back on the body.  When cured the cap was trimmed flush with the top and the neck was then fitted to the body.  The fitting ended up being almost a two hour process.  First I drilled for the bolts and trimmed the tenon so the neck slipped in snugly.  With the neck bolted to the body for the first time I checked the neck angle.  The neck doesn’t meet the body at a 90? angle… it’s more like 88?.  If it was 90 the strings would be flat against the body and it would be unplayable.   There’s a specific method of checking the angle…  Mine was too steep. It took 90 minutes of fiddling to get the angle right and the neck-to-body joint super tight.

With the angle set I trimmed the heel of the neck to length.  To cap the heel I glued on a piece of ebony and sanded it flush.  Once the neck was attached it would be hard if not impossible to finish sand the heel area so I did that.  Finally I permanently attached the neck to the body using a little bit of regular wood glue at the neck/side joint and torqued down the two bolts.

The ebony fingerboard was trimmed to size/shape and attached using wood glue, a shaped caul and plenty of C-clamps.  I decided to buy my fingerboard with the frets already cut and the top already radiused.  To have any kind of playability it is imperative that the slots for the frets are cut accurately.  I went with a standard Martin 25.4 scale length (actually 25.34″) and radiused to 16″.   I trimmed the neck to the fingerboard after the glue has cured and did the final sanding on the neck.

I’ll write up a seperate post detailing the headstock and the inlays…