Removing the Top to Repair loose bracing?

[Tim Mason]

Hi guys, i have an acoustic i plan on repairing, it has 2 braces that have fallen out and id like to re-glue them in. It is actually a friends old guitar and sounds quite nice. This is my first DECENT acoustic repair attempt.

I have a few heat guns and some Titebond orig. and all the clamping i need, but not sure how to tackle this one? Any tips would help alot, after all it is Anna's pops guitar and want to try to do it right,it's a little sentimental to her but she doesnt have alot of money. so i offered to help out.

Thanks for reading

[Bob Connor]

Any chance of posting some pics Tim?

[Allen]

Removing the top would be the last resort Tim. Give us some more info and pictures.

[Tim Mason]

Id love to post pics but i had to register again, with the hit ANZLF has recently taken, so im a restricted newbie

If you can change that for me im happy to post pics, the guitar is actually in fairly good condition, just the glue has become brittle and two of the braces have fallen off, im assuming the rest inside might be the same, just waiting for a good jiggle. The sides and back are held tough as nails.

Im hoping i dont have to take off the top, that would be good news

[Bob Connor]

You should be able to post pics now that you've made 3 posts.

Regards

[Kim]

the glue has become brittle and two of the braces have fallen off, im assuming the rest inside might be the same, just waiting for a good jiggle. The sides and back are held tough as nails.

I don't want to jump the gun but braces generally don't just fall off, especially a couple of them at a time. I think you need to have a very close look inside this guitar with a mirror and bright light. What you are checking for is to see if any of the braces have shifted or slid a little from their original footing, especially the UTB. If they have moved you should be able to see the glue line running along side them indicating where they had been originally. This is a pretty clear indication that the instrument has suffered at least one heat stress episode at some stage usually cause by being left in a parked car on a hot day or the like.

What happens to the guitar in such an episode is that the glue softens because of the excessive heat and string tension then moves the braces from their original position. When the guitar cools again, the glue firms up re-bonding the components in place, but the damage has been done because adhesion is very weak and the braces will come off easy as you describe. Other indicators of a heat stress event are a high action, cracks in the top running with the grain either side of the fretboard (easy to overlook at first), any deformities of the rosette, any deformities in the purflings of the upper bout either side of the FB.

If it confirmed that the guitar had at some stage suffered a heat stress incident severe enough to cause glue failure, it will need re-topping to effect a decent repair. Once apart, the integrity of the neck block, linings, and back braces will also need to be carefully assessed. As a general rule, unless an instrument exposed to heat stress has significant monetary or sentimental value, they are not considered viable to repair.

Cheers

Kim

[Tim Mason]

That's exactly what i were thinking Kim, heat. Hopefully the top, back and sides are ok, but this is a little strange. I cant see any damage using a mirror and a light inside the guitar, but i cant see any other way to correctly re-glue the bracing that has fallen off other than taking the top off

Still not able to upload pictures, i appreciate your thoughts so far guys, ill try post a pic ASAP

[Tim Mason]

[Tim Mason]

[Tim Mason]

Still no pic downloading, i tried adding some posts to the score card, not much else i can do... Well, enjoy the sunshine, i have a stack of Bournes potentiometers to test/compare with the CTS/Alphas excited!!

[Bob Connor]

Tim

Make a new post. Then have a look for "Upload File".

There is no pic upload like in the old forum software - it treats all uploads the same.

Once you have uploaded the file click the button that says "place inline" which will allow you to see where the pics will be placed on the page.

Regards

[Tim Mason]

Hmm...i cant see the "upload" button. Dont worry too much though, i know you guys prob have enough on the plate with the recent hacking. Ill might just try glue it back together by feel without taking the top off.

[Nick]

Tim, the new software version has an area below (if you scroll down) the posting area that says "Upload attachment" with sub headings "Filename" with an associated 'BROWSE' button & "File comment", once you've guided the software to you picture file on your 'puter just click on "add the file". It should upload your picture & display it in the forum as an attachment once you've hit the submit button. A little different than the old version I know but version 3 is a lot more stable platform so we have to make these little sacrifices I'm still feeling my way around it as well.
It should work for you.

[kiwigeo]

Hmm...i cant see the "upload" button. Dont worry too much though, i know you guys prob have enough on the plate with the recent hacking. Ill might just try glue it back together by feel without taking the top off.

Tim,

Lay a mirror on inside of the guitars back and you wont have to work by feel. Im in agreement with the other guys about not having to take the top of....it's a P in the A job.

Cheers Martin

[Puff]

Why not take the back off and work downhand?

[kiwigeo]

I class taking the back or the top off as major surgery and only done as a last resort. The last classical I built had to have the back removed 3 times and it's certainly wasnt an easy task.

[Puff]

Point taken but I would far rather take a back off than a top and far rather work in the open than with mirrors. If two braces have "fallen off" I would have doubts about the integrity of the others.

[Tim Mason]

Ahh... I see it now I should mention the bracing has come from the back, one close to the soundhole and the larger one closer to the ebd of the guitar.

Ok here goes

SDC10274.JPG (224.56 KiB) Viewed 20667 times

SDC10287.JPG (184.82 KiB) Viewed 20667 times

As you can see here the butt joint is looking a little shady
That is the glue line from one of the braces on the backing.

SDC10297.JPG (160.96 KiB) Viewed 20667 times

SDC10279.JPG (173.63 KiB) Viewed 20667 times

Ok, that took me an hour to resize and upload, time for lunch me thinks

[Puff]

Yes the fact that the fallen off bits fell off the back does modify things a bit

[kiwigeo]

Are the top and back ply? If so then are the braces actually necessary??......on alot of ply guitars I've seen the braces seem to be purely decorative in function.

[Tim Mason]

Yes sir, it is indeed ply. I am not sure about it being needed as such, but it will strengthen the guitar a little. It plays well, which really surprised me. Action and intonation were all fine, frets are average at best but the guitar is in good shape really.

Do you think maybe i should just cut some flexi sticks, place the bracing as best i can and wedge the sticks between the top and bracing being glued...

[Ronald_Handmade]

Should is a strong word. COULD definitely, but not sure about SHOULD...

[Tim Mason]

Hmm, lots i could do, but thats why im in here with the questions of how to fix such a problem, perfect oportunity to get some needed experience and i feel good for preserving Annas pops guitar
If i can do it without taking the top/back off that would be great, im more than open for ideas, Insom's last post has me doubting mine

[Ronald_Handmade]

Don't stress over my post - it was more tongue-in-cheek than it came across...

It actually sounds like a pretty smart, practical solution. I'd test-fit the braces and the springy bits dry first to make sure it will hold it steady enough though.

I should really point out that I'm a carpenter, not a luthier - if anyone can shed some more experienced light on this idea, please speak up now!

[Nick]

Hey Tim, if the geetar is ply it's probably a little 'hardier' than a solid wood acoustic so I would try sanding any old glue off where the braces sit then make a 'pad' that sits against the soundboard (to help spread the load) and make up some blocks (maybe 2, one for each end of the brace?) with a notch in that will locate the block on the brace you are regluing. The blocks don't go full height by the way, this gap (between the block & pad) will be filled with a wedge. So glue the brace & sit in place then put the block ontop of it & then gently slide the wedge in. It should only need finger pressure to push the wedge in, we only want to push the brace down on it's seat & get some glue squeeze out not drive the top and bottom plates apart!
That's only one possibility of course, or your idea of 'flexi' sticks (or any sort of 'jack' that's slighter longer than the gap between the brace & top plate) would work also, you are just trying to apply downward pressure, I would still make up some pads where the sticks sit against the soundboard just to spread loads.