#1
Hello,
So here's the deal: I recieved an old broken acoustic for free, I liked the sound but since I'm a lefty I went ahead with the conversion, new bridge + saddle + nut.
However I was dumb enough to use an electric sander and I took away too much wood (way too much)
The guitar still has it's magic but sounds thin, it's lacking body/bass.

I want to try and add some body back.
Please don't give me comment like it's not going to work, or whatever. I know it will never sound the same but I want to try anyway.
What I want to know: if you're in my situation, what would you add ?
Yesterday I added a layer of wood filler + wood glue + varnish all around the body.
It has helped and I'm liking the sound.
However it's not quite there yet, I still need some more body/bass to the sound.

Now I'm wondering if I can continue adding wood filler + wood glue + varnish (since I'm happy with the current result) or if I should add actual pieces of wood if so, hard or soft wood ?
I don't care about looks, I care about tone.

What do you think ?

Thanks,
Dave
Last edited by gerardi.david at Jul 23, 2017,
#2
gerardi.david  In truth, my best guess is what you're planning would only make it sound worse, not better.

Too thick of a finish is kind of notorious for killing the tone. which is why Gibson & Martin owners are rabidly fanatical about keeping their "nitro" finishes.
Wood filler is not all that resonant, nor is wood glue. What I think you'd effectively be doing, is creating one of the worse laminated tops, ever.

At this point, it sounds to me like you have either the wrong strings on the guitar, or they're not broken it yet. 12 strings sound particularly thin with new strings, that's why I hardy ever change them. The effect is particularly pronounced in twelves, the only reason I mention it. 6 strings fare a bit better, but they seem to lack bass with new strings as well.
 it
As far as your new, "custom thinned top",  I don't think I'd be hanging any mediums on it, it would most likely cause the top to bulge at the bridge.

OK, this post is a combination of "IMHO", and reasonably educated guesses. It's likely best if you sample opinions from the other "craftsman" (AKA, old farts like me), before you do anything.

At this point, if had the same issue, I'd hang a set of "custom lights" (.011 to .052) on it, and try to make the best of a bad situation.
Last edited by Captaincranky at Jul 23, 2017,
#4
Quote by Captaincranky
gerardi.david  In truth, my best guess is what you're planning would only make it sound worse, not better.

Too thick of a finish is kind of notorious for killing the tone. which is why Gibson & Martin owners are rabidly fanatical about keeping their "nitro" finishes.
Wood filler is not all that resonant, nor is wood glue. What I think you'd effectively be doing, is creating one of the worse laminated tops, ever.

At this point, it sounds to me like you have either the wrong strings on the guitar, or they're not broken it yet. 12 strings sound particularly thin with new strings, that's why I hardy ever change them. The effect is particularly pronounced in twelves, the only reason I mention it. 6 strings fare a bit better, but they seem to lack bass with new strings as well.
 it
As far as your new, "custom thinned top",  I don't think I'd be hanging any mediums on it, it would most likely cause the top to bulge at the bridge.

OK, this post is a combination of "IMHO", and reasonably educated guesses. It's likely best if you sample opinions from the other "craftsman" (AKA, old farts like me), before you do anything.

At this point, if had the same issue, I'd hang a set of "custom lights" (.011 to .052) on it, and try to make the best of a bad situation.
Quote by Tony Done
Captaincranky 

I agree with all of that. Remove all the gunk, and use light strings.


Thanks for the input guys, however I would rather hear what kind of material you would add.
The guitar is unplayable because of the thin sound and is already on a light gauge string.

It's either add material or never play this guitar.
Since I have nothing to lose, I want to add material to the body.

Considering the positive result up untill now, I'm thinking I should continue adding woodfiller & wood glue.
But I'm afraid I might lose resonance at some point because of this stiff material.
What would you add ?
I know I will lose resonance no matter what I add, but I'd like to minimize the loss.

I'm also considering a mix of woodfiller + glue + varnish + little pieces of wood/sawdust

Or should I add bigger chunks of wood ?
Last edited by gerardi.david at Jul 24, 2017,
#5
If you continue that process you are adding weight but not strength, so you will be stuck with light strings. If I was really keen to restore it, I would take off the bridge and cover it with veneer. But that's a big job.

I might also try nylon strings to get a thicker, warmer sound.
#6
Quote by Tony Done
If you continue that process you are adding weight but not strength, so you will be stuck with light strings. If I was really keen to restore it, I would take off the bridge and cover it with veneer. But that's a big job.

I might also try nylon strings to get a thicker, warmer sound.


Impossible to take the bridge off since I used superglue on this new lefty bridge I installed.
Yes I know another newbie mistake.
Luckely it's positioned just right, intonation is fine.

Nylon strings not an option either, I know it will not be played if put nylon on.

The mix of woodfiller & wood glue is really strong actually. I could smack it with a hammer and it wouldn't chip.

So in my mind it's actually the other way around, I'm adding strength but maybe I need to add some mass.
But what.. and how..

I do have another old acoustic I'm willing to salvage for wood, but it's cheap laminated wood..

Guess I will have to follow my instinct on how to proceed..
Last edited by gerardi.david at Jul 24, 2017,
#7
I can't quitems envisage what you mean. Adding wood filler will not improve your guitar. Post some pictures.
#8
Quote by Johnny_H
I can't quitems envisage what you mean. Adding wood filler will not improve your guitar. Post some pictures.

Basicly I've got an acoustic that I sanded WAY too much.
It's a pity because it has a great tone, but currently it's lacking volume/bass because of all the wood I took away from the body.
Currently I already added a few layers on the whole body, first woodfiller then woodglue then veneer all over.
I did this to make up for the loss of wood.
I'm liking the result, the tone has got some more volume & bass now.
I'm ready to take it a step further and add another layer so I can come even closer.
I don't give a **** how it looks.
I'm trying to decide what material I should add now.

I think I will need thin sheets of resonant wood now.. I can't keep adding woodfiller..

Thanks
Last edited by gerardi.david at Jul 24, 2017,
#9
gerardi.david  Well Junior, from personal experience I can state beyond a reasonable doubt, when we screw something up bad enough, life doesn't always provide the opportunity for, "a do over".

One of our members, EWCorduroy, is a luthier, and I imagine he would tell you that it's almost easier to build a guitar from scratch, than to go about repairing the one you have now. "Adding wood" to me, means laminating another guitar over top of  the damaged one you have now. But , if we're dealing with adding veneer to the body, the sides in particular. That wood would have to be steam bent,, then applied under pressure, using a guitar body mold . You've managed to make every mistake you possibly could, especially in using CyA to install the bridge. "Crazy Glue" is more or less forever, and now we have to laminate around it.

I have no way of knowing whether you're broke, or wildly headstrong. but it seems , at this point, you're, (again IMHO), against self interest.

FWIW, there are a lot more decent and fairly priced left handed guitars around now, than there were when I was growing up. (No that I"m an actual  grownup now, by any means).

So, were I in your shoes, I'd take my medicine, and start saving uo for a new guitar.

Keep in mind, I'm not going out of my way to discourage you, just stating the facts in a pragmatic manner
Last edited by Captaincranky at Jul 24, 2017,
#10
Quote by Captaincranky
gerardi.david  Well Junior, from personal experience I can't state beyond a reasonable doubt, when we screw something up bad enough, life doesn't always provide the opportunity for, "a do over".

One of our members, EWCorduroy, is a luthier, and I imagine he would tell you that it's almost easier to build a guitar from scratch, than to go about repairing the one you have now. "Adding wood" to me, means laminating another guitar over top of  the damaged one you have now. But , if we're dealing with adding veneer to the body, the sides in particular. That wood would have to be steam bent,, then applied under pressure, using a guitar body mold . You've managed to make every mistake you possibly could, especially in using CyA to install the bridge. "Crazy Glue" is more or less forever, and now we have to laminate around it.

I have no way of knowing whether you're broke, or wildly headstrong. but it seems , at this point, you're, (again IMHO), against self interest.

FWIW, there are a lot more decent and fairly priced left handed guitars around now, than there were when I was growing up. (No that I"m an actual  grownup now, by any means).

So, were I in your shoes, I'd take my medicine, and start saving uo for a new guitar.

Keep in mind, I'm not going out of my way to discourage you, just stating the facts in a pragmatic manner


Since I have nothing to lose but my spare time, I want to try anyway, even if it doesn't work out.
I like to fix things ever since I was little, so if nothing else atleast I gave it a shot. Giving up is not my attitude, even if all the odds are against me.
It's because I really love this guitar sound, even more so than my Martin & Guild.
Maybe it's that 60 year old wood that's giving me that sweet mellow tone.
This guitar was completely broken when I got it, cracked and detached all over the place.
I fixed the cracks but the sanding was a terrible idea.. too late
Live and learn.

So back to the question, what DIY material could I add to this project guitar to TRY and give it some more volume/bass ?
Last edited by gerardi.david at Jul 24, 2017,
#11
In your position I'd just leave it alone and accept that I fucked up big time. What you're doing to the guitar is horrendously barbaric from the perspective of a guitar builder. I can't really recommend doing anything else since any sane builder faced with the same problem as yours would just peel off the top, back and sides, throw them in the fireplace and build an entirely new body again from scratch. Simply because there is no other way to (properly) fix it.

If you think adding more body filler to the guitar gives it more bass and you want more bass, then maybe add more body filler. But I can't recommend doing that in good conscious; suggesting to someone to perform a massive bodge job just isn't in my nature. I'd rather do whatever it takes to get the job done properly, whatever that may take. Or if that's prohibitively expensive or impractical, buy a new guitar. 

I appreciate that you want to fix this, but you also need to remain realistic about the extent of the problems you can fix. And this is not one of them.
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#12
I don't know if you just sanded the top too much or the back and sides too.  It's almost impossible to sand a guitar that much EVENLY, so there may be low spots.  And I have no idea what make guitar this is, critical info on this forum.  Your best bet is to replace the top.  There goes the sound you like so much.  Barring that, sand off the filler & stuff and add veneer ( I might recommend Cedar for the top) with a light coat of recommended wood glue.  I use Elmer's wood glue or Titebond.  Laminate is usually run crossgrain but I would go ahead and run it longgrain.  Filler does not have grain which is figured into the guitar's strength related to bracing.
If the back and sides need thickening the veneer can be soaked to soften it for bending the sides then dried and glued on.
Then there's the matter of binding.
Best bet is to leave it like it is and hope for the best.
#13
Quote by skido13
I don't know if you just sanded the top too much or the back and sides too.  It's almost impossible to sand a guitar that much EVENLY, so there may be low spots.  And I have no idea what make guitar this is, critical info on this forum.  Your best bet is to replace the top.  There goes the sound you like so much.  Barring that, sand off the filler & stuff and add veneer ( I might recommend Cedar for the top) with a light coat of recommended wood glue.  I use Elmer's wood glue or Titebond.  Laminate is usually run crossgrain but I would go ahead and run it longgrain.  Filler does not have grain which is figured into the guitar's strength related to bracing.
If the back and sides need thickening the veneer can be soaked to soften it for bending the sides then dried and glued on.
Then there's the matter of binding.
Best bet is to leave it like it is and hope for the best.


I sanded the whole body too much and yes there are indeed low spots.
I will indeed have to add wood veneer.
Yesterday I coated the back of the guitar just as a test with more wood filler to hear the result.
I lost too much resonance, atleast now I know it won't work and I need some actual wood.

I have another old acoustic laying around which I will salvage for it's wood.
The next thing I want to try is take the back from that guitar and glue it to my project guitar, just to hear the result again.
Trial and error untill I get acceptable results
#14
gerardi.david it's probably just sounds different as you've taken the finish off. Add stuff on it NOT the way to go. Let's see some pictures.
#15
I'm very surprised that the thin wood isn't providing better bass response...not less. Less wood means the body can resonate better. Adding wood filler should damp the whole thing.  Are you certain you aren't mistaking loss of treble for added bass? If anything, I would have expected the bass to be so strong that it over-vibrates the top and distorts. 

Anyway, my thought is that you've learned an expensive lesson, but there is no real fix.   If you sanded the wood as thin as you've indicated, the body is eventually going to deform under the string tension. Nothing other than replacing the thin wood will restore your tone and strength to the body.  Wood filler and glue are not as strong as you seem to think they are. They are adding mass to the top which will dampen the treble, but no real strength.  

If you glue (and clamp thoroughly) a layer of veneer onto the top, you *may* add a little strength.  Of course, the bridge will need to be removed to do it correctly, and I don't know how you'll deal with the edge  binding. In the best possible outcome, you could have the equivalent of a laminate top.  But at what price in material and labor? Anything you do is really throwing good money (and labor) after bad. 

If this was my guitar, I'd probably get it back to bare wood and paint it with fiberglass resin. Then string it with extra light strings and resign myself to playing a guitar with crap tone until I could afford a new one. 
#16
tommymc 

Yes, thinner should mean stronger bass, it also leads to a "looser" sound that you might or might not like.

Another option you could try to add strength and permit the use of heavier string and possibly tighter response is a flying brace of the JLD Bridge Doctor type. I make my own, much more lightly constructed than the JLD, and I have had one in my very old L-00 for several years to stop further belly bulging. It seems to be working, and in this instance it sounds pretty good.