Re-fretting a Bozo

While I’ve done a post on re-fretting a guitar I thought it would be interesting to see some of the tools I use.  A small three corner file to bevel the edge of the fret slot so that the frets go in easier and when they have to be pulled less chipping.This is the tool I made for putting the 30 degree bevel on the fret edges.  It uses a mill smooth file with a high density, low friction plastic base.Flush ground end nippers for cutting frets close to the board.This tool cuts the tang off the fret ends to go over the binding.This is a small needle file with the edges ground and polished so I can remove the sharp edges from the fret end.This contraption I call Frankenfretter.  It’s a sliding base I bolt to the drill press to support the guitar while I compression fret it.  Notice the Taylor fret buck, a massive support for the guitar body while I fret.And finally, the finished job.

Basic Inlay Part Two

Now that we have the positive in mother of pearl, it’s time to cut the negative on the fret board.

While it can be done with hand tools, dental chisels, knives, etc., it’s much easier to do it with a Dremel or Foredom rotary tool equipped with the proper router style base.  Bases are available from several companies or you can make your own.  For much of my time inlaying I used a Dremel but have, in the last two years, switched to a Foredom.  While either will work the Foredom is much more powerful and most important to me the motor is well away from my ears.  I still wear hearing and eye protection but it’s much more quiet having the motor several feet away instead of having the Dremel right in your face.  The downside is that it is considerably more expensive.

I start by setting the inlay on the board and using a lead holderI can keep the lead much sharper than I can a standard pencil giving me better results.  Some people use a white tempera paint and a scribe and while this works fine with ebony, using open grain woods such as rosewood, the paint will be very hard to get out of the pores.

I use down cut spiral carbide bits to cut the channel for the MOP.  I have three sizes 1/8″, 1/16″ and 1/32″.  I use the biggest bit I can to get the job done, saving the 1/32″ for only the finest lines and details (they break if you look too hard).  I also use very good light so that the pencil line is clear.  I start at the center removing the bulk of the wood before I attempt the edges.  Of course, ebony is much more forgiving than lighter woods because the fill is easier to match.  One thing I’ve found comes in handy is a fish tank pump attached to the base so that it blows the dust away as you go.

I now carefully test fit the pieces.  It is very easy to break them at this point.  I often find the first time the piece will not always drop in.  I mark the spot that needs enlarging and route out again.

I use two methods of gluing.  On big pieces, I use epoxy and black coloring, fill the void and wait for the glue to cure, then sand back down.  In this case because of the fragility and the closeness to the fret slot, I place the inlay in position and lightly glue them in place with a small amount of cyanoacrylate.  Then once dry I can use colored epoxy to fill any gaps, making sure to avoid the fret slots.  The final thing is to now cut for the open “a” and “o”.  I do this with the Foredom with the 1/32″ bit.After cutting I simply fill the holes with black enamel and I’m done.

The trick to this is, of course, practice. Most of all have fun.

Basic Inlay Techniques

This will be the first installment of doing a retrofit inlay on a 40’s Martin D-28.  While we’ll be doing a signature, something that on the surface is simple, it is very demanding in technique and execution.

The great thing about doing inlay is that there is very little in the need of tools.  With the exception of big manufacturers’ use of CNC, very little has changed.  A jewelers saw, a rotary tool, such as a Dremel or Foredom and you’re in business. 

The piece of plywood you see in the picture is called a birds mouth and it’s used to support the substance to be cut, in this case mother of pearl.

The customer was having the neck reset and a refret and wanted his stage name inlaid in the fret board.  After we picked out the type style, I made copies for adhering to the MOP.  After gluing the type I start making cuts using the saw with a very fine blade that is .011″ thick.  When you’re starting out I would recommend a heavier blade of .021″.  You will break less of them but are limited in the fineness of the cut.  With practice, you can use finer and finer blades without breaking them.  I can usually do an entire signature without breaking a blade.  The actual “Country” measures about 1 1/4″ so you have to be very careful in placement on the birds mouth, making certain it’s supported on both sides of the cut.  Other important things to remember are to make sure the blade is perpendicular to the piece and to use the full length of the blade.  If the blade is not at a 90 degree angle to the piece you will put stress on the blade and produce a piece that is very hard to fit.  Make sure that you allow the blade to do the work and not to force it.  By using the entire blade you will cut faster and keep the blade from overheating.

You will notice from the picture that I am using my two fingers on top and thumb on the bottom as a temporary clamp.  You might also find a magnifying head band works to keep eye fatigue to a minimum.

Another thing to take into consideration is keeping the dust to a minimum by using a shop vac.  The dust is calcium based and something you don’t want to breathe in.

The thick and thin letters in this can be tricky so I always look to the hardest part first.  In this case I did the bottom of the letters first because they had the most turns and would be the most likely to break.  I don’t stop the blade when I come to a 90 degree turn but keep the blade moving rotating it until I get to the position I want, then continue.  If you’re careful you can cut the entire piece without breaks but if you do simply super glue the pieces together when you’re done.  Small needle files can be used to clean up and rough edges and as you can see, in this case I left the “O’s” and “A’s” closed.  They will be engraved when they are installed into the fret board.

Next week:  Inlaying the letters into the fret board.

Color Match Finish Coats

Now that we’ve got the color match we can complete the finish.

I then spray the top coats.  I start by lightly spraying in alternate patterns.  Horizontal then vertical, and then switching to diagonals to get the most even coverage.  I shoot 2 to 3 coats a day then sand with 320 grit wet or dry, being careful not to sand through the color coat.

Lacquer and other top coats follow, they don’t fill.  That means that the lacquer will flow into the depression not fill it up.  By sanding in between coats you are taking off lacquer on the surface while not touching the depression.  The next time you spray, the depression will be that much smaller.

I usually spray between 6 and 9 coats to get the desired result.  Prep work is critical because the less depressions and holes you have the less you have to finish.

When I’m satisfied with the raw finish I let it dry for a minimum of 2 weeks to allow the finish to cure and shrink.

When the finish is dry, it’s not a simple mater of putting the guitar together. The finish has to be compounded to smooth out the ripples.  Compounding is going through a series of abrasives until the surface is smooth and mirror like.

I start with no lower grit than 600 wet or dry and usually 800 grit.  I use the best quality paper. 3M Imperial wet or dry seems to work well.  The cheaper papers have larger stray grit in them and can cause scratches that are almost impossible to remove.  This is also the case if you start with anything coarser than 600 grit.

The first sanding is the most important. I lubricate with water to float the particles off and for less loading of the paper. It’s very important that you use a hard rubber, cork or felt pad to be sure of a flat surface.  Never sand with you fingers.   I make sure all the gloss is taken off so that the surface is dull but smooth and uniform.  Now I switch to Micro Mesh.  This is an abrasive in cushioned latex that doesn’t build up as easily and is very high quality.  The 1500 grit is equal to 600 grit sandpaper so I start with the next one up, 1800.  I continue with this to 4000 grit also using water as a lubricant.  Then I switch to another abrasive, Abralon.  This is a 6″ pad I use with a 5″ random orbital sander.  Using 2000 and proceeding to 4000, I use these pads dry.  I leave the 6″ pad full size to protect the guitar from the rubber pad on the sander.  In tight corners, I use the pad by hand. One thing to remember is to clean off all the previous slush so that the next grit starts fresh.

Now the fun part, using a buffer to bring the gloss up!  In reality all you are doing in each step is to make the scratches finer and finer until they appear to go away.  I use a Shop Fox buffer and 12″ domet wheels.  I make sure not to contaminate the compounds with the wrong wheel.  While they make several grades, I stick with the fine and extra fine.

Buffing wheels can be very dangerous if you’re not careful with the way they are used.  Remember when you’re buffing to only buff the bottom half of your piece.  Right

Wrong.

If you use the buffer like this you will run the risk of catching the upper surface and having your piece thrown to the ground.  I believe you will not like the result much so be aware of your orientation.

I do the same thing with buffing that I do with sanding, changing direction of the piece’s orientation with the wheel: horizontally, vertically, and diagonally. When finished with the fine wheel, clean the surface of the piece to clean the previous compound then proceed to the extra fine.  Wax is not recommended and will in fact make the piece duller.

When you’re done you should have a mirror finish to be proud of.

Color Matching an Existing Finish

Sometimes you encounter situations that require you to color match a finish.  In this case it is with a bass guitar that had its peg head shape altered and the client wanted me to match the finish as close as possible to the rest of the neck.As you can see, the fret board (as is the rest of the neck) is a dark amber color, much darker than the rock maple.

First, I sand to 220 grit to get rid of any scratches and prep the surface.  In fact I do this even if there aren’t any scratches to make sure there is nothing contaminating the wood.  Then I apply my sealer, in this case shellac.  You can also use vinyl sealer, epoxy and sanding sealer but in this case it was handy.  When it comes to shellac I try to always use flakes dissolved in alcohol with a date on it to make sure it’s fresh.  I usually use a 3 lb cut as a sealer.  This refers to 3 lbs of shellac dissolved in 1 gallon of alcohol.  It lasts for about 6 months so I don’t mix more than I can use in that time period.  It should be dry to the touch in minutes, and if it doesn’t it’s old and should be thrown out. The pre-made shellac in hardware stores contain too many additives such as plasticizers to maintain shelf life.  An interesting thing about shellac is that it’s considered a food product by the FDA and it’s what coats M&M’s.

I don’t like to stain bare wood for two reasons:  One it looks blotchy.  The soft parts of the maple will take more stain than the hard parts.  Two, if I screw up the color, I can take it off easier.  Here’s what it looks like with the shellac applied.

I mask off what I don’t want finished and mix my color.  I don’t normally shoot lacquer but in very small amounts I can get away with it (I’m allergic to the stuff).  In this case I’ll be using TransTint dyes sold by Stew-Mac, amber, red mahogany and medium brown.

Most of the color matching comes from practice.  I’ve done a lot of these so I use my experience to make a guess as to the colors and ratios.  In about 4 oz of lacquer I put 6 drops of amber, 1 drop of red mahogany and 1 drop of medium brown.  It’s very important to make a record of this and keep it in a journal.  This way you will be able to correct the formula if it isn’t right and repeat it if it is.  I test the color on a piece of paper and in this case it was pretty close so I went ahead and shot the peg head.  I do very light layers until I get the desired shade.
As you can see, it’s a pretty close match.

Next week, the finish coats.

Gibson Style O Artist part 4: Finish, Setup and Trouble Shooting

It finally looked like a guitar again.  I sealed the body with Tap marine epoxy.  I did this because the body was pretty dried out and I thought the epoxy would better integrate the surface.  It’s also what I do on my own instruments. 

After it dried a toner coat of  finish using yellow metal acid dye was applied over the entire instrument.  We had agreed to go with amber to dark cherry for the sunburst and dark cherry for the rest of the instrument.  I wanted to go quite dark on the edges and sides to try and hide some of the severe damage to those areas.  One note, I had put in the pearl dot at the center of the scroll, as per all the pictures I had seen, and when I sent the pictures of this guitar for approval on the finish color, I had forgotten about the conversation we had about omitting the dot. It was a quick fix, but also a reminder to write everything down.

After scraping the bindings I sprayed 6 coats of KTM-9 (before anyone howls, I’m severely allergic to lacquer and don’t have that much experience with varnish) sanding every two coats.  I tinted the finish with a slight amber color to tone down the new ivoroid, and to blend it in with the existing pieces. Although I’m not sure that was necessary because only the heel cap, soundhole surround and the tip of the Florentine cutaway survived.  I also saved small jars of the colors so if I went through the burst I would have a match to the previous colors.  It probably would have been smart to document the ratios, but if I were smart I wouldn’t be building guitars for a living.

On the Gibson HG I repaired I didn’t finish sand the final coat of finish, just buffed it out to a gloss leaving all the imperfections.  It is an 85 year old guitar and it was decided that it should look a little lived in.

The tailpiece had been broken and Jim had that fixed but the plating had been compromised, so he found a place to get it re-plated.  The holes for the bridge pins were way oversized by wear, so I used some celluloid pickguard material to line the holes of the celluloid tailpiece, and cement them with acetone. The hardware was installed next, followed by a level crown and polish of the frets and cutting the nut slots. It was interesting to me to see that in most of the pictures of Artist O’s the three in line machines were installed upside down, the knobs being below the posts.  Since the back of the peghead was now free of any holes I thought it best to put the Waverly’s with the name up as on a modern guitar.  I was concerned that they might not hold up as well upside down since they weren’t designed to be used that way.

I only had light gauge strings on hand and even though I thought they’d be a little weak in tone, I was anxious to hear how the guitar sounded.   After bringing the guitar to pitch I was thrilled with the sound.  It was much more alive than I had thought it might be, very rich, even with light gauge strings.  Unfortunately, it became obvious I was not finished with the job. After only five minutes the top on the treble side had started to cave in.  A depression was forming around the foot of the bridge and I immediately detuned the guitar before I had a catastrophic failure.  Apparently, my predecessor had been a little too overzealous in his working of the top and it was way too thin.   I didn’t think to check the top’s thickness before I installed it on the body.  This is another mistake I will not make again.  I thought the best way to handle this was to make a “bridge plate” much like a flat top.  I used a piece of cross grain Indian rosewood at .09” and formed an arch approximating the arch on the Gibson with a heating iron.  Then I used the topography created by the new braces to give me an approximate bridge plate size and cut and fit the rosewood so that I had a friction fit between the braces.  I figured that with a tight fit to the braces that the top under the bridge wouldn’t deform as much if it had support.  Once that was done it was a simple matter to make cauls and glue the plate in.  I was lucky that the Artist O has an oval sound hole that I could fit my hand in.  If this had been an L-4 the “f” holes would have been a much harder job. 

After letting the glue overnight it was time to string it up again and hope for the best.  The good news was that after a couple of hours there was no more deformation and even better news was that the bridge plate didn’t affect the tone at all.  It held tune and was actually louder than it had been without the plate.  Only time will tell if it was a complete success. 

Would I do it again?  Probably not at this price.  Was I sorry I took the job on?  Absolutely  not.  It was a challenge, but I feel that I got quite a bit out of it, and transformed a bag of kindling into a guitar again, a guitar that would be played and not just hung on a wall.  Jim Richardson may not look like Big Bill Broonzy, but he might someday be the coolest guy in the nursing home.