Sanded too thin

[kingarex]

So i'm working on a cheap les paul special 2 and I have been experimenting with finishes and techniques. I have sanded through the veneer to the natural wood which looks great, but I've sanded it so many times in my experiments that wood over the knob cavity is so thin that you can flex it with your finger.... Not something I anticipated. Is there any hope for this? I thought about making a plate out of metal but I think it will look stupid. I thought about fiberglassing or gluing the back of the wood cavity to add rigidity but I want to know the "Right" way. I REALLY don't want to chuck this body as I need to sell it, but I also don't want to sell junk. 

[sumgai]

Put the metal plate inside the cavity. Then be honest when a potential buyer asks "what's this for?".

Don't do any more sanding, period. Make it all look as nice as possible, then sell it. You were going to anyway, now's not a bad time to off-load your 'experiment', and start over with a new one.

Good luck!

HTH






sumgai

[ssstonelover]

Actually you can buy wood veneers which are typically 0.5mm thick. To build up thickness you can take such veneers and glue them into the cavity to thicken up the weak points.
Simply trace out the shape you need on paper and trial fit it. Then using that pattern cut the veneer to the same shape and glue it in the cavity. Since the veneer is so thin, you can cut it with a scissors or exacto blade (of course take care as it is fragile). You can also take a Dremel and sand remaining difficult edges to shape (since the veneer is fragile and 'directional').
It sounds like you might need to use 2 or 3 veneer layers to build up the thickness enough.
After you have all the veneers in place, go back in with your drill bit and reopen the pot holes to the right size. The existing partially closed hole help keep the drill bits centered and with some care you can get great holes back on the body.

In case you haven't guessed, I have some experience in this. Once or twice in a control cavity, but also when adding veneer to a neck headstock (such as rosewood on a maple neck) after which I have to drill through to reveal the tuner holes again. Forstner bits, Brad point type, etc, help give a clean cut to avoid splintering, as does having a support piece of scrap wood on the other side of the hole so that when you punch through the hole it is 'clean'. After all use all the tricks at your disposal to avoid mistakes or ugly execution...and pre-planning is part of that.

If you are really tight for money, you can even take a paint stick (usually some cheap pine and ~3mm thick from Home Depot available for free) glue it up in the pattern shape you drew (typically wider than what a paint stick is), then sand it down to the thickness you need, then insert it into the cavity and then redrill the holes.... easy-peasy. I've used that technique too in guitar bodies to fill voids, and it would work perfectly well here too.

Oh, final point. The ideal way to place the veneer (or thinned out reshaped paint sticks) is in opposing grain direction (like a plywood).... The flex will be gone.

This will give you some idea of what you can do with glue sticks, where I had to cover even bigger areas and some manufacturer's errors. (process shot)


If you do it right no one will know or care... (after shot)

[kingarex]

These are both fantastic ideas, thank you so much, and also thank you for not taking the very low hanging fruit and flaming me... I'm doing that all on my own!!!! I'll remember the stir stick idea, that looks unbelievable, and DUH put the plate on the inside... Sometimes my (what's the opposite of genius?) surprises even me! I love this site. It's a shame, after I sanded through the veneer and glue on this les paul, the body wood is SO good looking, I have ZERO idea why they covered it... It's baffling. I experimented with different paint types, and some mica powder/alcohol mix and then with different clear coats. If I'd have known just how little room there is to play with, I'd have spread my experiences out over all 8 bodies that I have rather than doing them all on this one (My thinking was, choose the cheapest guitar, get good at Dye, stain, paint and clear with that body then take the refined knowledge and practice to the higher end wood bodies that I have). Anyway, 8 or 10 full sands later, I'm comfortable enough to do a "final" finish. So I put black dye on it, let it dry and sanded it back just enough so the deep grain is dark but the top grain is natural color. The contrast is phenomenal it's beautiful! Anyhow, a valuable lesson learned. In addition to this boner, I also took a super strat body, and on my first day in my new wood shop many months ago I ran it through my planer hoping to smooth out the body (someone before me sanded the original finish off, spray painted government vehicle matte white and decided it looked awful, so they impatiently tried sanding THAT off with what i'm assuming has to have been an angle grinder with a welding flapper disc, or what looks like 36 grit... They did not "keep it moving" so there were lows and highs EVERYWHERE.) Anyway, by the time I got it flat, it was like an inch and a quarter thick... I test fitted the parts and now the trem block sits higher than the back plate, and the neck sits high like a cello. I could cut down the sustain block, but I don't want to route the neck pocket deeper as I believe it would certainly compromise the structural integrity. So I'm probably going to cut it in half so I have two .75 inch full guitar shaped pieces and use the two slices as body and cavity templates, respectively. Ugh....Thickness is a bigger deal than I anticipated. You see a guitar body and think "Look at this slab of wood!" In reality there's little margin for error. I know this now. Good news is, I've been able to make the other 6 bodies look great. I have a 71 Univox bass that my buddy's uncle left him. He used it for live shows when we were in our band in our teens and 20's... It had a lot of road wear and was a chipped and cracked sunburst finish, Using my experience from ruining these two bodies, it's now it's a Nuclear green stain with beautiful wood grain!!!! I can't wait to give it back to him and see his reaction. (I've had this bass for like 15 years... It sustained a neck crack and he felt awful. Not knowing how easy of a repair that is, he was going to trash it. I offered to take it and use it as a wall hanger in memory of our gigging days. I don't even think he remembers that he gave it to me broken all those years ago) He's going to poop. 

[ssstonelover]

I still learn (and make mistakes) all the time, but it's all about recovery and not repeating the same mistakes, so that you are building on the experience, but you already are set to avoid repeat boo-boos, so at this point you are on your way forward. Better days ahead! And, yes, dimensions are VERY important for intonation, tremolo fit, action adjustment range, strings not 'falling off' the fretboard and pickup placement. My first partscaster had lots of rework and burned indelible memories into my brain on the process of controlling critical stuff, and accepting things could/and would go off the rails if vigilance relaxed at any time. A good rule of thumb is to fix anything 'dead-on' with necks/bridges first and build around that.

Here is one way to start setting that up....making sure the neck is not crooked and the bridge is in a good spot for intonation range -- then do the drilling.

[kingarex]

Oh very nice. I haven't cut my own blanks yet but this looks like a great way to approach alignment setup. I'll be using this.