First broken headstock repair question

[Mack McDonald]

I've been a fledgling luthier for awhile now, and only do it a few hours a day and mostly on inexpensive instruments.  It's a break from playing really, and gets my second love of tinkering satisfied.  I refer to Frank Ford's frets.com for info frequently.  I've gone to Frank once in the past for info, but now he refers those with repair questions to this site.

 

Just got my first broken headstock on a Epiphone acoustic.  I got the glue up done alright, but infortunetly the owner didn't save the missing pieces.  So now I need to improvise.  I haven't done the "is it lacquer or is poly test?" but since it's a newer guitar from Asia I'm assuming it's poly.  By the way, I have filled poly finishes in the past with tinted super glue, but as you might know it leaves that "drop of oil in a bucket of water" opaque look.  Not that it really matters on this guitar, but that I'd get some more experience.

 

Here's the front of the headstock with missing chunks of finish and wood.  I thought I'd try epoxy this time with Behlen burnt umber tinted to get the color close then scrape, sand, and buff.  Then I thought I would paint in the darker grain where it would be missing.  I know, but I have to try it for the experience.  Thoughts from anyone?  Finish to put over the top of the painted grain?

 

 

 

 

Now here's a photo of the back of the neck.  Yeah, it's a huge hole and I'm really not sure about this one.  Unless someone says something differant, my thoughts are;  cut a rectangular hole using a knife (what kind & where?)  dremel or saw.  Leaving a slight inward taper on the cut.  Then take a mohagany dowel and and mirror the taper, cut a groove for the truss rod to move, leave it proud and again...scrape, sand and buff ???  What kind of finish can I put over the bare wood that would work well with the poly?  Anyone?

 

 

 

 

I know this seems like a lot of work for this guitar, but I'd hate to try it on a more expensive guitar for the first time.  And, the kid that owns it probably wouldn't buy another guitar.  There's not a lot of discussion about matching poly finishes including frets.com, and maybe for good reason.  Except for the UV dentist tool and that's not going to happen for me.

 

Just want to get it as close as I can, thanks ahead for any help anyone can offer...

[Russell Vance]

Have enclosed a few of our things for inspiration - new peghead facings are easy, look new and add strength to the damaged area - if you're up to woodworking I'm a great fan of laminating over an existing break after removing the shattered wood - it's strong, stiff and blends into the existing grain pattern fairly well. Laminations also cover our proprietry carbon fiber reinforcements which bridge and secure the major damage areas.

Other wize just glue it up, fill it with bondo, scuff the neck (key it) and spray a dark nitro shader over the whole affected area and then finish coat the whole neck - I don't blend poly, especially in wear areas like this.
Rusty.

[Happy Builder]

hey mack

first the top

after glueing you could laminate with 1 mm of wood venear since it is flat it should not be a problem you may also remove 1 mm of old wood if thickness is important

then the back
cut out some extra oval shaped wood from the back then match and join on the back -- oval should be book matched with the centre

then spray a dark shade over the head till the joint you grafted and the top

prefferably give a final coat to the whole neck

or you could just give it a new neck - more hassle but its new -- trust me making a new neck takes as much time as repairing a broken one -- only difference being cost of wood- dont have to bother about matching wood grain , matching the finish , matching the colour etc.

[Rick Gentry]

As a serious hobbyist, I would want to overlay the front of the headstock also. I like doing that anyway, and it adds a ton of strength to the repair. I would carve a long oval out of the back and fit a new piece. Definitely not square.

I remember an article by Charlie Hoffman in a Stew Mac publication where he glued the broken headstock back, carved half the neck joint out, added wood, shaped it, AND then did the same to the other side. It looked amazing. Maybe he could re-post it? As I recall that was a traditional Les Paul break, a little closer to the joint and shorter than the one on your Epihone, but it could work if you elongated it.

[Pierre-Antoine Roiron]

Considering the guitar, I'd go CA for the headstock plate as you said. Epoxy is a mess to deal with in that situation.
For the back of the neck, it's a real problem : I would'nt make it the way you suggest : too much endgrain involved for a simple re-glue. I would thin the area using a cylindrical wood cawl and glue a cylindrical piece of mahogany in place of the wood sanded. I'm not sure if my English is good enough for describing that process. For the finish touchups I usually use nitro lacquer on poly for touch ups : that's the best way to leave minimal witness lines. So i would fill the grain, seal it with lacquer, then sand the whole area lightly. Then I'd shoot some black to mask the repared area, then clear lacquer then buff.

[Mack McDonald]

Lots of ideas from you guys that I would never have though of. I like the idea of a replacement veneer for the top. I'm thinking the original is rosewood but can't tell for sure. I'll lose the decal though, already tried it.

I also like the idea of the oval in the back. But, what tools do I use to accomplish this? Remember the surface of the neck oval pattern is likely to be below the truss rod. Will the glue surface be flat the entire pattern, then lay the patch over proud and finish the contour? I'm somewhat confused on this one...

When everything looks like it's going to work I plan on sanding the entire neck and finish with nitro...more questions then.

[Len Biglin]

as a side issue does anyone have a name for that species of wood seen in the neck above? It looks like wavy mohog. but has almost no strength and will snap straight across the grain. I guess its an Asian tree as they seem to use it most? Len

[Rob Mercure]

Hey Len,

I believe it's one of the "Luan's" - can't remember the genus right now but they range from almost balsa wood to some that are much harder and denser than mahogany - with the true kicker of being sujected to local variety in color, "grain" (not real annual rings), and strength. Luckily it's one of the easiest of the SE Asian trees to identify - I've got a whole box of "sort of likes" and "almost could be.s"

Rob

[Happy Builder]

hey mack

for the back -- take a computer print out of an oval form -- stick it will plain glue over the hole -- now chisel away at the edges -- 45 degree angle to the base -- now print out one more paper oval -- take a pice of wood with curve like the back and chisel off outside of the oval -- now try and match this piece to the neck -- sand or file some more till it fits-- i have tries fitting without an outline and it is always not perfect -- with an outline you are stuck to go by the line -- sometimes the grains on the wood are misleading illusions for a perfect symetrical oval -- stick to outline -- send some snaps when done-- good luck

[Mack McDonald]

Thanks Happy Builder... I've already started and found the damage doesn't go below the truss rod. I had followed Russell Vances suggestions and photos, except I'll be doing the oval. I'm sure there'll be enough surface wood for a good glue up.

I don't know if everyone caught my concern about spraying nitro over poly finishes. The best I can tell so far, is that I'll need to strip the neck to finish it with nitro. I've also heard that there is no stripper that will work on poly. So I'll be sanding and trying not to disturb the wood too much. Am I thinking right?

[LARRY KLOSE]

I don't think over-spraying nitro on poly is a problem.

I had to have some repair work done to a Brazilian bandolim headstock overlay--it had been worn down below the finish on an edge for some reason I can't recall. It was finished with Poly. The luthier over-sprayed the overlay with nitro with no problems and it was impossible to tell the difference. Might show more on a patch area on the back but if you're refinishing the whole neck it should work fine after roughing the poly.

My issue with nitro on necks is that it gets soft under some people's body chemistry. I worked on a friend's guitar and the neck was so gummy that a fingerprint would show. He could destroy a set of uncoated strings in about 3 hours, too. On my own (nitro) guitar, I get some white bloom on the top if I play a lot in humid summer conditions and the neck finish also softens a little. I'd go the other way--poly on necks even if the rest is nitro.

The builder of the bandolim I mentioned told me that he uses mostly poly because it is stable in the almost constant high humidity environment around Sao Paulo. He started out using French polish but said most of his customers preferred the poly because of the environmental factor, which caused a lot of damage to more tender finishes..

[Pierre-Antoine Roiron]

See the last 3 lines of my message higher in the page.

[Ned Knepp]

Amateur Ned here.
I definitely would follow Rusty's instructions except that I would have filled the hole with a rectangular block of wood that was relieved to fit around the truss rod, if needed. Cutting the opening into an oval then fitting a oval plug to it just seem to be too much work.

The neck could be preped for a block by squaring up the opening with the "with grain" sides of the opening cut flat to the plane of the block and the "cross grain" ends cut with a 45 degree taper towards the center of the hole (like a scarf joint). Cut like this it should be possible to make a wooden block that was cut with 45 degree angles on each end that would drop into the area. laying flat on the edges that are parallel with the truss rod and being cut at 45 degrees to fit the cross grain edges of the hole. The block would only need to be the thickness of the cut depth. If relief was needed for the truss rod it could easily be cut the length of the block before gluing it in. The block could then be shaved to fit the contour of the neck and the whole thing could be reinforced and hidden via Rusty's instructions.

Ned