MIMF

by **Randy Roberts** » Sun Aug 17, 2014 4:29 pm

I'm considering making a guitar, smallish, maybe Martin size 1'ish, for a friend who is slowly retiring and increasingly sailing the Carribean.

I was considering a Formica/ epoxy/ something but would really rather have it look like a real guitar.

I'm looking for suggestions materials, glues etc. from any of you that might have dealt with the problems of humidity, salt air, etc.

Maybe teak, epoxy/ SS frets, Nylon strung?

Thanks in advance.

by **Matthew Lau** » Mon Aug 18, 2014 2:07 am

Why not plywood?

There's also wood looking formica too.
I may recommend music maker's ply (haven't used the stuff.)

It'll be interesting to see what you make.

by **Clay Schaeffer** » Mon Aug 18, 2014 10:18 am

If you can find some alpicord you can have the best of both worlds. A prefinished wood veneer bonded to HPL. I would consider using WRC for the soundboard, because of rot resistance and I think it moves less with humidity changes ( I could be wrong - anyone have any hard data?)
I like the size one guitars and have been considering building one out of those materials with the removable neck "travel guitar" design I've made before. For the limited spaces of a sailboat it might be just the thing.
Epoxy might be a good choice for gluing things together, or perhaps titebond III.

by **David King** » Mon Aug 18, 2014 9:56 pm

What about marine plywood? I've seen some very high quality 1/8" sapele plywood used in model boat kits so I imagine it must be available somewhere. There are lots of glues that will work well in this situation. CA would be tempting as would polyurethane or West systems. I used Titebond II on a lot of instruments in the 90s and never had any trouble with it. My recollection is that it's a little harder than the TBIII.

by **Clay Schaeffer** » Tue Aug 19, 2014 9:32 am

http://www.alpiwood.com/en/Alpikord_Collection

But plywood won't give you faux wenge, macassar or zebrawood. The piece I scrounged looked somewhat like cypress.

by **Craig Bumgarner** » Tue Aug 19, 2014 1:38 pm

My day job for the last 40 years has been boats, so I have a little experience. Boats get VERY hot inside in the tropics, especially when closed up when not in use. The insides of a boat can easily be over 120 degrees or more when closed up at noon in the sun. Humidity levels are very very high. Salt air coats everything with salt which holds the moisture and is murder on hardware. Lightly built wooden things go nuts in that kind of environment.

Many sailors I know have carbon fiber guitars, like the RainSong, on board. These seem to work well except for steel hardware and strings. If I was going to build a wood guitar for this environment I'd laminate as much as of it as I could, using epoxy resin only for glue and seal all surfaces, inside and out with epoxy resin before finishing. Modern wooden boat builders have been doing this with WEST and other brands of clear epoxy for 30 years and it works very well. Try not to use steel hardware. Steel strings are going to be tough to keep from rusting, so a nylon string model might be in order.

Keep in mind even with all this, long term life might be limited.

by **Bob Menzel** » Tue Aug 19, 2014 2:24 pm

You might consider Richlite for the board and bridge (ala Martin).

I'd probably go with a high grade Finnish Birch ply for the neck, and would use a Hysol epoxy for the joinery (one with high temp attributes).

One of these days I'm gonna try my hand at laying up a Kevlar body to use up the leftovers from a canoe build, but doing it well calls for a vacuum pump and bag system, and there's just no room on my plate right now for such an endeavor.

Kevlar might not offer the acoustic properties of carbon fiber, but it would be more durable. And, if you played as poorly as I do, shielding your vitals with Kevlar could be a big plus... :)

by **David King** » Tue Aug 19, 2014 6:30 pm

Just for the record, formica curls up like a dead leaf when the humidity changes very much. The back gluing surface must be quite hydroscopic.

by **Bob Menzel** » Wed Aug 20, 2014 12:07 pm

It may be slightly hygroscopic, but it curls because the finished surface is less hygroscopic. This probably isn't much of a problem once the sides are bent and mated up with a braced back and top. Does Martin seal the inside of X Series bodies? I suppose that for a guitar to be kept on sailboat that one could seal it.

by **Clay Schaeffer** » Fri Aug 22, 2014 2:11 pm

I've taken WRC topped/formica bodied dulcimers backpacking and had them rained on with no ill effects. I've also taken them to the beach. I also question the ultimate longevity of HPL, but haven't seen it fail yet (10+ years).
One guitar I built I interleaved carbon fiber cloth between rosewood veneers. On the veneer laminates I make I experience some "bleed through", but since I use an epoxy fill it isnt a problem. If a person went heavy on the epoxy they could essentially impregnate the wood fibers with it and have an epoxy/ wood composite material that should be fairly impervious to humidity changes (first dry the veneers in an oven to drive out any moisture then immediately laminate with plenty of epoxy).
Home building a carbon fiber guitar might also be a possibility, but wouldn't look like wood.

by **Mark Parker** » Wed Aug 28, 2019 3:37 pm

Clay Schaeffer wrote:. On the veneer laminates I make I experience some "bleed through", but since I use an epoxy fill it isnt a problem.

Why isn't it a problem? What is your technique for grain filling?
I just did a set of side laminations with West System on some curly maple and got lots of bleed through. I thought maybe applying a coat of epoxy to the sides to 'grain fill" would even things out, but it didn't. The bleed through spots are still prominent and, of course, it didn't bleed through all of curl so the spots it did stand out.

by **Clay Schaeffer** » Wed Aug 28, 2019 5:29 pm

Hi Mark,
I posted a reply in "Glues and Finishes" but also check the archives for other peoples experiences with epoxy pore filling.

by **Barry Daniels** » Thu Sep 05, 2019 7:07 pm

I use a chopped polyester fiber additive in my West Systems epoxy layups and it helps to lessen bleed throughs.

The bleed through areas are probably a lot more filled (due to packed pores) and this may be the cause of the different look. You could try letting the non-filled areas sit for a couple of hours under wet epoxy to give it maximum time to soak in.

by **Mark Parker** » Thu Sep 05, 2019 7:34 pm

[quote="Barry Daniels" You could try letting the non-filled areas sit for a couple of hours under wet epoxy to give it maximum time to soak in.[/quote]
That's what I did and it worked. I used the slow hardener and left it fairly thick for a while before scraping it down and now things look quite nice. I am relieved.