My New Spectacular Mats Needs Some Help...

I have a thread going over in the Mats forum ( LINK ) but I thought I'd cross post here as well and tap the grey matter of the membership.

Short story: I obtained a gorgeous Vantage 12 string acoustic, circa 1982. Got it for relatively little money which is good, along with a few minor dents. The bad news is that she suffers from a swollen soundboard behind the bridge making the action unbearably high past the first position.

She's mahogany back and sides finished in antique cherry burst with solid spruce top and Indian rosewood fretboard. You can see detailed shots of the soundboard in the original post, but here are some pix to get you started:

The Beautiful Back!



And here are the sides...note the arched back




And a couple more for good measure



I've had some terrifically detailed advice from the boys over there but I'm no craftsman, and I'd hate to bugger this up as you can imagine. Have any of you had experience flattening out a raised soundboard? What did you do, and how did it go? I appreciate all input.

Hi Barry,
That is a gorgeous guitar. I have a SIGMA (cheap half of Martin) fro the early 80s i.think with exactly the same issue. i did wonder about removing the saddle , shaving the bridge and refitting the saddle lower but not sure if this is a good/recognised way to repiar it.

Will be watching with interest

Ian

I had a Takamine 12 string where the bracing under the top became seperated just under where the bridge sits. This also caused terrible action and basically was unplayable. See if you can get a mirror in the sound hole to see if that may also be your issue. It only takes a little bit of separation to ruin it.

I have no experience repairing acoustic bracing but I imagine it is no easy task. I think the proper repair in that case is to remove the top completely to get the repair done.

GULP!

Ian, if you read the Mats post you'll see a detailed description of how to reduce the top of the bridge (no removal). But that's something I'm still thinking about. I don't have the tools so it would have to be done by hand, a bit problematic.

Sarc, I actually have an inspection mirror on it's way to me. And, it has a built in light! That will answer the loose brace question one way or another. If there is a loose one there's no need to remove the top. You can get at it from inside. Ain't easy but it can be done.

bridge doctor, works everytime, can't go wrong, you won't know its there. i know i have used them. don't shave, sand or anything else on that guitar, it will be a headache in the future when it gets worse! bridge doctor, a permanent fix, or replace the bridge plate, which can be a headache! personally, i'd have the bridgeplate and forget the bridge doctor, but is you are not familiar with doing it, and don't know what to use to remove it, reinstall a new one with etc etc etc, just use a bridge doctor. all the bridge plated i've replaced hold up perfectly. shaving bridges etc is just vandalism!

bridge plate! bridge plate! bridge plate!

then keep it tuned to d, and use a capo @ the 2nd fret if you want e

BRIDGE PLAAATEEEEE!!!!

Um, ya think it may be the bridge plate then?

Funny thing in the first page in reviews @ JLD Bridge Doctor someone mentions:

" Through research I found it would help to humidify the box and to stack a weight on the top for about a week or more to stabilise the flattened
position prior to installing the bridge dr. ".

Bellying of guitars often occurs when guitars are kept in too humid conditions I read elsewhere (pics) http://www.taylorguitars.com/sites/default/files/10_SymptomsofaWetGuitar.pdf Not everybody seems to like the bridge doctor according to other comments. Drilling! Will it fit this bridge plate? Further the site mentions that for a twelve string the brass pin mount is advised and of course you'll need 12 bridge pins instead of 6. Costly? Can't find a 12 str version with 12 pins or what it will cost!

there is no drilling with the ones i bought, you can call the guy and tell him you need one for a 12 string, and thoese brass bridge pins make a difference to the tone some. for better or worse, thats up to you, but most like it, that i have spoken too. i called the guy that makes them, abd before i sent him a cheque it had arrived! no cod, no nothing, very trustworthy, his wife was very hospitable as well. Like you've been advised already, it could be the bracing, but in most cases it is the bridge plate, really not that hard, you dont have to remnve anything but the bridge plate under the bridge. the main problem you may come across is that some bridge plates run under the bracing a little. while you are waiting for your "periscope" to get to you. find a small mirror and a flashlight, lay the guitar on its back, ubstrung and put the mirror in the soundhole, under the bridge and look, sometimes laying it(mirror) on its backbraces can be a good way of doing it. you'll see the bracing of the top and bridge plate, then you'll know if the bridge plate goes under the bracing. only awkward thing is, if it it the bracing, it may have gone back into place as there are no strings pulling on it. but thoese bridge doctors do work, use the phone number on the website, if you don't feel good about fixing the bridge plate your self, use a luthier. i think that you use the 6 string version of the bridge doctor on a 12 string. just don't buy the cheap one that requires drilling your bridge!

christoyoyo wrote:...i think that you use the 6 string version of the bridge doctor on a 12 string.

Correct. But it's recommended to use brass pin style since there is not enough room on the bridge to drill; the octave set runs just where you would normally attach to the bridge doctor.(Wouldn't want to drill anyway)

You then have the option to replace just one or all six of the pins with the brass ones. Aesthetically I think may look odd to have 6 normally pinned strings and 6 strung thru the brass pins (ball ends showing). And I'm still not convinced there will be a proper break angle generated by this method.

Still, others do not seem to be having any issues, and if it's restricted to the octave set perhaps it won't matter much since they are somewhat drone-like anyway??

i've used nail polish to match my bridgepins before, there are so many shades you'll find one that is the right match, you wouldn't know unless i showed you, it lasts forever, and is easy to find. it works on brass too. personally i loved the difference the brass pins made. if you only used 6 on your 12 string it may suprise you, use your old pins and match up some nail polish. you can find the bridge doctors on feebai from time to time cheaper than new, just make sure they didn't cut the dowell

as far as the ball ends showing, i've never been that petty

christoyoyo wrote:as far as the ball ends showing, i've never been that petty

Sheesh, "petty"?
I just think these don't look right:

honestly, i like it!

when you're playing doesn't your forearm cover them? instead of a closeup, why not a pic of the whole guitar?

christoyoyo wrote:when you're playing doesn't your forearm cover them?

Ah, no. Only Johnny Cash could do that!

well then, i'll tell you my next secret, pop the balls out, run the string through the pin and the loop the ball used to be in... whats the problem with that? alot of people use brass pins, essentially then your colorful balls would be gone, and you would upgraded your pins and fixed the bulging bridge????

Hmmm, interesting idea, I think.


But if I'm understanding correctly, I'm not sure I'd want the string kinked so sharply especially the twisted portion. It's kind of like a locking machine head except there's no clamping action to stabilize it.

it would be as stable as stringing it regularly, try it and see. eventually it all "shores up" as it always does

I'll file it away for later reference.
Cheers.

hope it helps

mini update:

I received my inspection mirror today and took a few pictures, with mixed success. (It's harder than it looks).
Updated pix

believe it or not,its an easy fix,it is going to need a new bridgeplate period. and that is a cheap ply bridgeplate, at least it goes across the grain of the top(dont quote me but it looks like a cheap as hell ply top too).... replace it with an ebony bridgeplate, and before you think you're finished, check your bracing... string it up for this! look for separation.... remember no matter what you're told, humidity is not the only enemy, cheap guitars did not come with expensive bridgeplates! like solid wood going across the grain of the top.. as you seem a novice, fork out some $ on a luthier and have a permanent fix, or get a bridge doctor, or don't get it fixed at all.....

PM sent....

Admin

geez now we need the naughty chair for this thread as well.
I think it's time for a bit of a time out from this

[quote="christoyoyo"] check your bracing... string it up for this! look for separation..quote]

I agree, you want the strings on and up to tension. With no strings if there is any separation, then without the tension it may not be visible. Still it's above my head for repair advise - I haven't tried to work on any acoustic repairs yet.

Sure, putting it under tension sounds ideal, but then you have to pass an inspection mirror past 12 strings and then try and get a clear view of the inside. You simply cannot manoeuvre this or any other tool inside the guitar (a snake LED camera probe being a possible exception).

Normally, the bracing components are 'explored' with a brace wedge to determine how well they are attached. What you cannot see in my pix is the quality of the (hide) glue which appears clear, clean, and to be well applied and holding quite tightly, as you might expect from a Mats era guitar. The pics showing the white powder are the exception and found only in one location. Jury's still out on what that is but I'm thinking now it may be polish residue from a long ago (sloppy) cleaning.

addendum: In case you missed it on the original Mats thread, this is a flamed spruce top with mahogany back, sides and neck. Definitely not plywood, and not a cheap guitar.

Looks like solid woods to me and cant see any cracks in the glue joints (but of course that doesnt mean they arent there). Can you get a hand in the soundhole and dig your finger nails into the joints?
I guess if the bowing is still apparent with the string tension off then its there whatever, no?
In which case I would go with the clamping across the top (or a weight like a book) while moisturising the underside, steady eddy on this tho, take weeks, container of water in body with sound hole blocked?
Problem could well recurr in which case additional bracing required such as the bridge dr..

grogg wrote:...I guess if the bowing is still apparent with the string tension off then its there whatever, no?

Yup.

...steady eddy on this tho, take weeks, container of water in body with sound hole blocked?

Something like that, yes. Just being in a high humidity environment is not having much of an effect. Trevor, over in the Mats forum suggests, dampening the underside directly with a moist towel.

Can you get a hand in the soundhole and dig your finger nails into the joints?

No, not really. Not a very good idea anyway. Hard to see, even with the mirror. Tapping the soundboard does not reveal any rattling, buzzing, or dramatic changes in sound so the assumption is that all bracing is solid.

Problem could well recurr in which case additional bracing required such as the bridge dr..

That's the current plan. Flatten her down as much as possible then further reduce and/or stabilize with Bridge Dr. I don't really wish to spend another $50-odd dollars for one but...

BTW, I did a little look about on the subject of bridge plates and apparently rosewood was used by Martin on many top models so I'm in good company! It's the choice of a lot of custom builders too. Rosewood is somewhat harder than Maple which makes sense since it must resist the rip and tear of 12 strings in this case. Tonally, it's perhaps not as bright as the often used Maple, but more so than Spruce which is the most commonly used bridge plate wood. Those are the ones you normally see chipped and cracked because they're so soft.

Well, I bit the bullet and decided to order the Bridge Doctor.

I read a lot of first hand accounts on a lot of acoustic guitar forums, and the overall result was way more positive than negative, especially for 12 string guitars which tend to suffer more so with bridge rotation and bellying up.

The worst accounts I heard was, "it didn't work". But most important, I did not hear of the BD causing any damage. And, since I'm using the brass pin version rather than the drill-thru-the-bridge version, it's easily reversible if needed. The original nut has a small chip in it so I'm also going to replace it, as well as the saddle and the pins while I'm at it.

Film at eleven...waiting.