Repair on a 1962 Martin D-28
George Leach
At first glance, it was obvious that this repair would be a lot of work. The guitar looked like it had been sat upon, with its top partially caved in, and lots of cracks. This wasn’t the real problem however, since top cracks are something any repair person fixes all the time. In fact, it would have been preferable to leave the top on the guitar, since it could still be “all original” after the repair. The real problem was that this guitar was in a very serious accident shortly before its current owner, a friend of mine, bought it for $75.00 (more on that later). Upon examination, I found that the scale length of the instrument was just over 1/8 inch too short. The neck had somehow gotten shoved forward, toward the bridge (see photo #1), the top was caved in, with braces severly cracked, and everything had been glued back into place (with epoxy) by some repair facility in the distant past. It became obvious that the best repair for the guitar (the owner wanted a playable instrument, not a collector’s item) was to remove the neck, remove the existing damaged top, and put on a new top.
Photo #1:
It can be seen that the soundboard wood under the fingerboard has been split from the rest of the board, and shoved forward. As it turns out, the scale length has been shortened by about 1/8 inch, and the instrument isn’t really tuneable.
First of all, I don’t do a repair like this on a guitar like this without the owner knowing that We're not the local Martin repair facility. Though the guitar would never again be “original” with a new top, the owner didn’t care about that, he just wanted the guitar to be playable again.
The first step in removing a neck is to separate the tongue from the top. I use a small (2” x 6”) heat blanket.
I hold the heat blanket on the fingerboard with a radiused block, and use a small knife to separate the fingerboard from the top.
Photo #4:
Next step, remove the 15th fret with a pair of fret nippers, then drill a couple of holes through the fingerboard, into the neck joint.
Photo #5:
Next, steam is injected into the holes in the fingerboard. This is done with an old cappuccino maker, with a tube attached to the steam nozzle. The other end is attached to a basketball nozzle. I use a water trap between the steamer and the nozzle, to catch the water and allow mostly steam to go through to the nozzle. The idea here, is to soften the glue in the neck joint, and allow the neck to be pulled out of the dovetail headblock. I’ve done this many times, in doing neck resets. However, this neck needed something extra.
In this photo, I made a small jig out of mahogany to fit around the fingerboard. It is held in place with the two outer clamps. The middle clamp puts upward pressure on the neck joint, and the cutout in the jig allows room for the neck to move up when the glue joint becomes loose. Steam is still being injected, but for some reason, the joint refuses to loosen. Finally, after about an hour of injecting steam, and no real sign of the joint loosening, it’s clear something is wrong, but what? I start applying more pressure to the neck by hand.
Photo #7:
With a little pressure, the neck snaps off, right in my hand. Clearly, this neck had a couple of fractures in it, and a little further inspection showed that there were more cracks in the heel—waiting to cause a problem.
Photo #8:
Here’s the rest of the neck heel, right where it used to be…It’s still being steamed and pressure applied vertically, but it won’t move. It all needs closer inspection.
It’s time to remove the top and take a look at what’s really going on with this guitar. I use a putty knife with a knife edge ground into the end. It is sharp enough to slide into a joint like this, and thick enough to separate the top easily.
Now it becomes obvious what’s going on. Clearly, this guitar has been dropped, and cleanly split right down the headblock, and around the sides. The repairman used epoxy to hold it all back in place, but was pretty sloppy with the application, and epoxy has squeezed right into the dovetail joint. Time to inspect the joint—since we can see it better now.
It’s hard to see in the photo, but just below the break-off point, the joint has epoxy in it. No wonder steam wasn’t loosening the neck. The next step will be to try and clean this epoxy out of the slot, so the steam will do its job.
A long drill bit is used to drill through the epoxy layer—and see how thick it is. As it turns out, it’s about 1/8 inch thick. It shouldn’t be too difficult to chisel out.
Photo #13:
A good 1/8” chisel is used to clean out the slot in the dovetail block. Once all the epoxy is out of the way, steam should have no trouble penetrating the glue joint. It is doubtful that enough epoxy really got into the dovetail itself to be a problem.
Again, it’s hard to tell from the photo, but the shine down in the slot this time, is the bottom of the dovetail joint—clean of epoxy. We’re ready to steam—again.
With only a few minutes of steaming, the rest of the neck heel pops out. Now it can be seen that the crack went right through the neck heel. Everything was epoxied back together. It can be seen from close inspection that there are a couple of more hairline cracks in the heel—waiting to cause a problem later.
Photo #16:
Here, the neck heel is being reglued.
Photo #17:
The heel is being drilled to take a dowel. Since the heel has a couple of cracks, I’m going to epoxy a ¼” dowel into it for stability.
The dowel, inserted, epoxied, basically, ready to go….Now, it needs a new heel cap.
Now, we’ll put the neck aside for a while, and finish the new top. The photos start after a new top of AAA grade
Carving the braces: I use a curved-sole plane to carve my scalloping pattern into the braces.
The finger braces are carved with a chisel.
After carving, the new top is glued onto the guitar body.
The new purfling and binding slots have been cut, ready to glue.
The purfling and binding have been glued. The rosette can also be seen. I chose these patterns, because they’re very simple, and very clean.
Photo #24
Here's another view:
Photo #25:
Now, after sanding and scraping, it's time to spray lacquer. I stuff the soundhole with newspaper:
Photo #26:
In this shot you can see my portable spray booth. The spray booth uses an explosion-proof exhaust fan. A lazy susan holds the guitar body, so it can be turned in any direction for spraying. I'm using nitrocellulose lacuer for this job, because that is what the guitar was originally sprayed with.
Photo #27:
I will typically spray about 3 coats, then sand to level the finish. This job took about 10 coats, with 3 between-coat sandings, then a final coat and final sanding.
Photo #28:
In this shot, I have fit the neck, and am using a sharp blade to scribe the finish where the fingerboard will be glued to the body. I always use the back of the blade as shown. This gives more control. When the front of the blade is used for this job, it will be more likely to wander and not stay right where you want it.
Photo #29:
Here, I'm using a laminate trimmer, with a 1/8" cutter, and the blade depth set to only a few thousandths deep to get through the finish. I use this technique to scrape away most of the lacquer.
Photo #30:
Next, I use a chisel to scrape away the lacquer right at the scribe edge.
Photo #31:
Here is the final result: a clean wood surface to glue the fingerboard to the soundboard.
Photo #32:
Now, it's time to work on the neck. After re-gluing the heel, you can see an ugly crack line. It can bee seen that after the last crack, the repairman painted the heel black to hide the crack. I will be using that same technique here. Since the black color is already on the heel, I will re-color it, and blend it over the crack to hide it.
Photo #33:
First, sand the crack and the area around it.
Photo #34:
Next, pour some lacquer into a jar for mixing.
Photo #35:
The black pigment is added to the lacquer.
Photo #36:
Now, the black lacquer, is poured through a filter into the spray cup. I use a smaller spray gun for this kind of job--for 2 reasons: First, I don't like to put colors into my main spray gun. Second, this smaller gun gives better control for spraying a small area.
Photo #37:
Now, the heel is sprayed.
Photo #38:
Now, the neck gets glued on. I noticed that I had left off the heel cap, and put it on before gluing on the neck.
Photo #40:
Now, it's time to work on the bridge. First, I need to remove it from the original soundboard. I use a small heat blanket, about 2" by 6". I use an artist's pallette knife to slide under the bridge as it starts to lift, and a block of wood to hold the blanket down without getting myself burned.
I work my way across the bridge, heating and sliding the knife under to separate bridge from soundboard.
Photo #42:
After a little sanding, the bridge is ready. I remove the lacquer the same way as before, by holding the bridge in place and scribing around it. I also drill 2 holes--through the two outside peg holes to put in screws to align the bridge while gluing.
Photo #44:
Here is the bridge, clamped in place. The alignment screws remain in the peg holes until the bridge clamps are removed.
Photo #45:
Next, the saddle slot needs to be cleaned out. I use an old Stew-Mac jig with a vacuum attach for this job.
Photo #46:
From this closer photo, it can be seen that the saddle slot is very dirty. The previous saddle was not original. It was cheap plastic, which broke away and left a residue as the saddle was being removed.
Photo #47:
Here is the jig with the laminate trimmer attached, and the slot cleaned out. This jig was originally made for a dremel tool, but I have found that a laminate trimmer is a much better tool for routing into ebony. It makes an excellent, clean slot.
Photo #48:
Now, the 15th fret slot gets a brief cleaning out with a fret saw--and a new 15th fret gets inserted.
Photo #49:
After a little fret work, buffing and stringing, here is the guitar, and my customer. The wait is finally over! My shop is in the background, along with my partner, Diana Huber.
Photo #50:
And finally, here is my customer, about to smash his newly repaired guitar, after getting my bill.
