‘65 GIBSON SG, Pt. 2
March 16, 2007
After the truss rod threads and nut are waxed, I use a drop-fill toothpick and hair dryer to apply the System Three epoxy.
Greetings to all of you Premier Guitar enthusiasts! Last month’s issue left off listing the top ten reasons our clients give for broken headstocks on their most treasured guitars, as well as assessing the damage of a ’65 Gibson SG headstock break.
Clearly, this was not one of the more straightforward headstock breaks that we usually encounter. This kind of clean break is the most difficult and timely repair. Many years ago, the neck was stepped on and now would not go back together very well for the rebuilding process. I used my exacto knife to trim some of the splinters on both ends of the break, till the seam line would pressure fit closed.
A special fixture – more commonly known around the shop as a jig – will be relied on to get the proper clamping angle (17 degrees) and pressure that is needed. Our custom jig is made out of hard rock maple wood, cork, wood screws, a strip of carbon fiber, and two turnbuckles. Before applying any glue, you first want to dry assemble this project. It’s very important to put the jig in place and clamp it up to full pressure, as if you were clamping it for the last time with glue. This will give you one last opportunity to work out all the bugs, if anything isn’t quite working according to plan, before you glue it up for real.
It is very important to wax up the truss rod threads and nut before applying the System Three industrial epoxy. I’m using Turtle Wax, which I purchased at my local auto supply store. This will reassure us of any possibility in damaging the truss rod. If glue does get in the truss rod nut area, the wax will allow us to break the epoxy loose and will also work as a sealant so the epoxy will not penetrate and absorb into the surrounding area. Warning! Do not get any wax on surfaces that you want to glue together, as this will work against a solid and strong glue joint.
After the truss rod threads and nut are waxed, I use a drop-fill toothpick and hair dryer to apply the System Three epoxy. I went with medium hardener curing time, so that I could get the glue to sit where I wanted and have it work as a filler as well; otherwise there would be an overwhelming amount of thin epoxy ooze seeping through the glue joint and gaps.
Using the drop-fill toothpick to gracefully apply glue, I then use the hair dryer, set to warm, to channel the glue through the damaged cavities. Once there is glue applied to both ends we are ready to jig it up. The snapped headstock is inserted into the headstock support box. The neck block portion of the jig is secured by tightening down the fingerboard clamping arm and Cclamping to the guitar neck.
Evenly finger-tighten the turnbuckle clamps until you get a snug fit. Allow the glue to set-up for 48 hours before removing the clamps.
Now that the System Three Epoxy has cured to a very hard and strong texture, the headstock repair jig can be removed. At this stage of the repair, I like to use superglues from stewmac.com to fill in the concaved areas where the damaged break seams are. I drop-fill using #10 thin and #20 medium cynoacrylate with accelerator to speed up the curing process. I first level the glue to the original finish with a razor blade and then finish off with 600 grit sandpaper. This is the final stage to strengthen the break before routing for the reinforcement splines.
Next month, we will be jigging up, routing out two sections of the neck/headstock and inlaying two reinforcement splines.
You can view past articles on “Restoring an Original” at premierguitar.com or brownsguitarfactory.com
John Brown, of Brown''s Guitar Factory, is the inventor of the Fretted/Less bass.He owns and operates a full guitar manufacturing and repair/restoration facility, which is staffed by a team of talented luthiers. He is also the designer of guitar making/repair tools and accessories that are used today by instrument builders throughout the world.