Laminated guitar repair research project

[nkwak]

I have a little research project that I'm doing. As much as I would love to get practiced enough with building to maybe do a commission I feel like I need to take on repair projects. This was one that I literally had laying in my basement. I was wondering how some of you more experienced folks would do this.



The guitar is a 50 year old all laminated Japanese-made "lawsuit" Takamine that suffered from heat stress at some point in its life before and during my ownership of it. The bridge came up and took part of the laminated top with it. I contributed to it by sawing off the neck poorly after discovering that it wasn't a dovetail joint. The saw bot through the outer veneer and even well into the next layer, but the heel covers most of it. I confess it looks pretty ugly but I see it as a challenge.

Here is the scope of the project. I realize that it is not representative of any single repair/restoration project. I see this more as 4 projects in one and even if I don't completely restore this guitar at least I will have at least (possibly) picked up valuable skills. I'm looking forward to the tinkering aspect of it.

1: replace the top/binding/purfling. I just did something similar on a scratch build. I was hoping to save the binding but I look forward to improving my skills in that area as well.
2: repair damaged side veneer around the neck joint. I have black veneer to overlay the affected area but the cosmetics will be the challenge.
3: convert to a bolt on butt joint. Aligning the neck will be the challenge for me but I already have the jigs and I've used threaded inserts before - just not with so long of a bolt.
4: replace the fretboard. I've seen it done with a clothes iron and a Japanese pull saw. I probably won't replace it with another rosewood fretboard.

This won't be a high priority project but I need to do something with this other than to hold my wooden cauls under my workbench. It would be nice to hear this guitar sing again since I made a lot of progress as a player on it. I may even try to find it a new home if one of my kids doesn't want it.

[tippie53]

its a good learning experience , since the guitar is not valuable I like your try and learn attitude

rememeber to take your time work it through , and do. As you make mistakes you know what to do and what not to do. Reading and watching videos is great but getting the experience is what makes it the best for learning,
post lots of pictures. and do it this way

make one part of the fix the procedure you do at a time don't try to to it all at one.
as you do this , ask questions post pics and discuss , once you have a plan proceed

[Stray Feathers]

Neil, I am almost done a similar job, retopping a 1970s Yamaki - in fact, they look eerily similar:

viewtopic.php?f=53&t=9796

The construction parts went quite well, though I created a mortise-and-tenon neck joint rather than a butt joint, which worked fine. The biggest problem has been in the finishing. After replacing the bindings and purflings, I had to sand the sides flush, and that removed finish from some areas, down to below what looked like stain in parts of the laminated mahogany sides. I spent a lot of time with stains and fillers and pigments trying to even the things out appearance-wise, but not very successfully. I've been struggling with spraying a water-based finish (because I didn't think lacquer would stick to the original plastick-y finish) and I'm not sure how well it will level and buff out, and how bad the blotches will look. I have come to think it might have been better to strip the old finish entirely. But like yours, this is not a valuable instrument! I hope to get the last two coats on tomorrow, then wait for the recommended four weeks to level and buff. Bruce W.

[nkwak]

Neil, I am almost done a similar job, retopping a 1970s Yamaki - in fact, they look eerily similar:

viewtopic.php?f=53&t=9796

The construction parts went quite well, though I created a mortise-and-tenon neck joint rather than a butt joint, which worked fine. The biggest problem has been in the finishing. After replacing the bindings and purflings, I had to sand the sides flush, and that removed finish from some areas, down to below what looked like stain in parts of the laminated mahogany sides. I spent a lot of time with stains and fillers and pigments trying to even the things out appearance-wise, but not very successfully. I've been struggling with spraying a water-based finish (because I didn't think lacquer would stick to the original plastick-y finish) and I'm not sure how well it will level and buff out, and how bad the blotches will look. I have come to think it might have been better to strip the old finish entirely. But like yours, this is not a valuable instrument! I hope to get the last two coats on tomorrow, then wait for the recommended four weeks to level and buff. Bruce W.

Wow! I read through your thread and the similarities are eerie. Here I thought I was going to get talked out of it but you've given me some hope for the old boat. It's actually sat in this condition for a number of years but this year I've really tried to kick things into high gear so that the lessons I learn stick and I don't forget them!

First things first, I need to tally up all the materials I'll need to acquire. At first guess, I'd say:
- a new spruce top
- most likely a StewMac rosette because I've done 3 this year and I'm pretty comfortable doing them
- braces for the top
- possibly new lining for the top; what's there looks too thin for my tastes
- plastic binding
- a new bridge
- a new fingerboard
- fret wire
- a nut
- a saddle

As for what to do first, I think I'm going to try and tackle the exposed area around the neck joint. Or maybe I'll see about removing the fingerboard. I need to think more on what to do next. I'm also in the process of building a mold for it.

[Stray Feathers]

Neil - I did not address your patch near the neck heel. Has the outer veneer layer been removed? If not, you may be able to stain what's left. If you have to put in a patch, you can try to match it of course, but maybe also put in something contrasting - a "design element" patch. And as I said, for me, preparing the old sides, with some bare wood, some scuffed old finish, and some sanded transition zones between, has been a challenge. If you are using plastic binding you may be able to more closely match the remaining binding, and not have to rout it out - a whole lot less work. Bruce W.

[nkwak]

Yes, the outer layer has been sanded away to expose what looks like poplar beneath. I also had a section of ivoroid binding come off, exposing the channel so that could measure the depth. I have some veneers of dyed maple (I was considering on using either black or a mustard telllw)
and undyed mahogany and maybe tinting it dark brown. I’m also probably going to have to take off the rest of the binding.

I like the idea of making a mortise/tenon but would still use brass threaded inserts.

I’m also in the process of removing the fretboard, but I hit a snag and broke the fretboard. It split along a grain line.