Repairing a crack and shrunken pickguard on 1970’s Martin D-35

A beautiful D-35 walked in the door, I repaired some unattached binding- then it came to my attention the shrunken pickguard had actually cracked the soundboard.. I had not planned on blogging this repair, so I didn’t take pics of the original binding repair or the heavy warpage of the pickguard. The project was challenging, but the outcome was worth the effort..  😉

Since the pickguard had let go around the edges and curled upward, it was pretty ugly. At the bottom edge it had curled up almost 3/8″ and become perpendicular to the top of the instrument. Where the glue was still intact, the shrinkage had pulled so hard against the wood that the wood cracked. This necessitated removal of the pickguard to unload the tension, as well as attempt to reverse the warpage,  repair the cracked wood beneath, and reattach it properly. That’s where this story begins..



I successfully removed the pickguard without damage to the substrate or the original finish.



The crack below the pickguard (right along the edge) was raised and unsupported from below.. the extended tiny crack was raised a bit, but is backed by the internal bridge plate, thus ugly- but stable.


This is the problematic area, right below the pickguard. Below is a shot of the same area with a high-power flashlight shining through the wood..


I then traced around the pickguard and made a template from 1/4″ Lexan- a smooth, fairly sigid plastic that will support the entire surface of the pickguard during glue-up.

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I raised the grain with a damp rag, to open the pores of the wood and allow the glue to penetrate deeper into the wood.20140626_051137


Then made sure the Lexan caul was a perfect fit to the body.


I cut pieces of thin card stock until the shape fit inside the instrument and avoided all the bracing. The pressure I need to get everything aligned and flat during gluing requires support from inside- there is no other way to get a flat, strong, permanent repair. Eventually, these shapes were cut from 3/4″ MDF and covered with waxed paper to keep the cauls from being glued inside the guitar (if glue seeped out).


Then I filled a hypodermic needle with wood glue, and injected/pushed glue into the voids. I worked from the interior and the exterior, using a flashlight, camera, and mirror.

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Once I was satisfied there was enough glue coverage, I applied the interior caul, a temporary Lexan caul, and a couple of clamps. Left that to dry completely.



As nicely as it turned out, I didn’t feel it was a strong repair. Yes, the crack was fixed, but further shrinkage of the pickguard over time would likely open up the repair- and it can only be glued one time. Cured glue will not stick to itself. Basically, do it right now.. One chance at it.

So I machined a little cleat from maple, with the grain running in the opposite direction, fitted it, and clamped/glued it in place. It is a very thin slice (about 1/32″ thick), but the crossgrain orientation and the natural strength of the maple will reinforce the top without significantly altering the sound of the instrument. Nice fit, tight, light, and strong. Mo’ better.. lol

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Pinpoint accuracy is key- don’t want anything rattling inside when I’m finished.


Once the cleat was in place and all excess glue had been cleaned, I painted the underside of the pickguard with Titebond glue and placed it carefully in its original footprint. Then I set the Lexan caul on top of the guard, and carefully fitted several clamps and interior cauls- adjusting the position along the way. Eventually, the entire pickguard was in place and flattened. Obviously, I try to clean up and excess glue as I go. The reason I chose Titebond as opposed to a solvent based glue is that Titebond is water based and will not damage the original finish. Wood fibers were still bonded to the underside of the pickguard- leftovers from the original attachment. The Titebond works great on wood, but not great on plastic. Since there was a coating of wood fibers stuck to the underside of the guard, the Titebond had plenty of wooden surface to create a durable bond.

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I let the assembly dry for about 6 or 7 hours, pulled the clamps and cauls, then cleaned off the remainder of the excess glue with a slightly damp rag. Then I hand polished the finish and the pickguard to restore the original shine.

I then polished the fret tops, cleaned the gunk off the fretboard, oiled the ebony, checked the inlays, and installed a fresh set of Martin strings.

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I’m very happy with the result, this is a great guitar. Looks better than if I had just squeezed some glue into the open crack and stuck a new pickguard on it- it looks, sounds, plays and feels “right”.  Gorgeous.  😉







Construction of Rice Custom Osprey 205

I started out with some claro walnut, trued it up and clamped/glued it-

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Once the glue was completely dry, I sanded it down to a consistent thickness and set it aside to rest, under pressure.. I wanted to make certain it was stable before proceeding. The photo isn’t that great a quality, but the wood is breathtaking.


I then acquired a hefty slab of black limba.. Cool piece of wood.


I cut it to size, and machined it to be proper thickness.. DSCN1407 DSCN1408 DSCN1409 DSCN1410 DSCN1411 DSCN1412

Once everything was perfect, I mounted it on the CNC machine, and cut the chamber and wiring slots.. DSCN1415 DSCN1418

I then cut the walnut top to exact dimensions, and laminated it to the limba slab.  I used a second slab to keep everything stable, and 18 clamps. That should do the trick. Now I’ll leave it in the clamps and let the glue cure.  Worked out beautifully. 😉 DSCN1420 DSCN1421 20140613_191927_resized

OK.. I pulled the clamps early in the morning, and block sanded everything for a couple of hours. I don’t want to go too far, but I like to have the bulk of the block sanding finished before running the next steps.. Just seems to work out better this way for me.   I put the blank on the CNC, and did a whole bunch of work there..

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A trip to Mr. Bandsaw and edge sander.. DSCN1426 DSCN1427

And a bit of hand sanding- Leaves it here for the moment..

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I recessed the neck bolt holes, then did a deeper-than-normal radius around the front and back.  Feels real nice against my belly.. LOL DSCN1432 DSCN1435 DSCN1433 DSCN1434

————————————————————Beautiful mahogany! I prepared and sized/squared it up, and got it fitted for the machining.. 20140701_100011[1]

Then got everything going on the machine.. 20140702_075736 20140702_120817 Once it had been rough shaped and had the truss rod channel cut in, I separated the excess and hand shaped it. Much more refining to go, but the basic carving and shaping is roughed in now.

20140702_124638 20140702_124729   Hand fitted the neck to the neck pocket. Nice, tight fit.. 20140702_132238 20140702_132325 20140702_132317 20140702_132255 Next I’ll start carving the neck/headstock transitions- always done completely by hand- I’m very particular about the way that transition fits my hand.. 20140703_085320

Roughed in for the moment. I’ll refine it after the neck is complete. Pretty good start, though.. The next sequence are random shots taken along the process of truss rod channel prep and fitting the truss rod.. 20140703_091912 20140703_092024

Stepped hole drilled for the adjustment nut.. 20140703_092702

Fitting the rod

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Good fit now. 😉 I cut a filler strip from rock maple- very tight fit- and installed it. 20140703_113556 20140703_114549 20140703_114612 20140703_114724

Once the filler strip was in permanently, I mixed up a dollop of epoxy for the anchor point.  Not really necessary, but it always makes me feel better. I’ll grind off the excess and plane the strip flush prior to installation of the fretboard. 20140703_121754

OK.. the glue set up, I pulled the clamps, and whittled down the maple strip.. Takes a while..  😉 20140703_145351

I protected the edges when the strip got close- don’t want to disturb that surface. 20140703_145403 20140703_151404

Scraped it just about perfectly flush with a sharp blade.. 20140703_151652

Then sanded the surface flat on a big granite slab. Now it will sit for a day or so, to get used to being a neck (as opposed to some pieces of wood and metal).. I like to let it stabilize for a while, and will give it one more minor leveling right before attaching the fretboard.


The pistachio fretboard blank arrived, so I trued it up on the jointer, wetted it, and clamped it between two stout pieces of rock maple to allow it to equalize temperature/moisture. Leaving it loose would allow it to warp.. extreme pressure will help force the moisture into both flat sides..



After it sat for a day, I pulled the clamps and dimensioned the blank on the thickness sander..

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Measured the thickness, checked for warpage, then re-wetted both flat surfaces and clamped it up once more.

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It’s a gorgeous piece of wood. It will stay clamped for a few days, just to be certain it is stable, then be machined into a fretboard.



Machining the board..20140807_101749


Roughed in for radius, fret slots marked.

Hand sanding 16″ radius. This is very pretty wood…




Marked and drilled face dots..

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Installed the pearl face dots and sanded everything flush..




Outdoors shot for better color..



Prepped the fretboard and neck, aligned everything, glued and clamped it home..  Looks great!




Front of body with bridge pickup set in place- nice fit. 😉


Rear of body, sealer coats sanded and first coat of semigloss lacquer applied..