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Hey guitar gurus this sunday morning i thought i would prep my guitar for final coat. Well as I blowing it off I heard a loud bang, that was the sound of my guitar top popping off the bass side of the guitar. I blew into the neck mortise and since the sound hole taped off the was no where the air could go and boom. Please give me suggestions should I cut the top off or glue it back down, and if I do that will it affect the sound? I can get all of the top sitting back down to its original position, with seam supports under the cracks you think I will be ok? I honestly cannot believe this happened. There was just some extra dust in there that I wanted to get out for final coat.

Please help,
Robbie

It's hard to really see what's going on. Since your binding seems broken, I think the best course of action is to rout of the binding off and see what's happening. It may be as easy as re-gluing the top to the linings and redo the binding. Can you see anything inside the guitar with a mirror? It may be that the linings are cracked as well.
Best way I know to blow off the dust is to hold the soundhole close to a dust collector hose (or a shop vacuum one) and blow air through the soundhole. The dust has nowhere to go but out.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

After further inspection the top is the only thing that lifted not the kerfed lining. Do you think that I could glue the top back down and put some seam supports under the small cracks??

What kind of glue did you use and how long has it been? Looking at the joint failure, what happened? Did the glue fail or did some of the wood tear away with the glue?

Mike

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Mike Lindstrom

If you used titebond or another PVA glue, you'll need to scrape the bonding surfaces back to bare wood.
These glues don't stick to themselves well. If you're using HHG, you can just reglue on top of the old glue.
It may be better to rout off the bindings and pull the top completely off the guitar so you can clean
everything up well, then reglue. It's a shame, but it's a lesson on how high the air pressure forces can
be if you're blowing into a closed volume.

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Gene

Politicians and diapers must be changed often, and for the same reason- Mark Twain

Just glue it all up, add some heat.

Look at it this way, you just invented a new technique for removing acoustic tops!

You need to name it!

Oh, and be careful with the vacuum hose (use one smaller than the sound hole, I have heard of folks imploding guitars that way)

Mike

I bet superglue and clamps would also work to hold that little area back down.

I think it also underscores just how much damage you can do with compressed air....

Think -- 5 psi x 200 sq-inch surface area face of guitar top = 1,000 lbs of force trying to rip it apart!
Just think how much worse it could have gone if that side glue joint would have held.

Same thing for a vacuum -- There are several guys here who have completely imploded a guitar with a normal household vacuum cleaner.... Stick it in the soundhole to vacuum out some swarf.. Let your hand cover that hole by mistake and *Whamo* it just sucks the whole top in...

The other thing I would worry about with compressed air is the "Sand Blaster" effect -- A good blast that picks up shop swarf could scratch things up pretty good or embed junk in the guitar.... I have seen a standard air blow gun shoot a bolt clean thru the wall of a steel "Butler" building by mistake... Guy didn't notice that he had sat it down nose first on a bolt in some sort of freak bad luck.... picked it up and "Pow" -- right thru the side of the building... Found it laying in the yard outside.

Anyway, I hope your fix goes well.

Thanks

John

You're not the first guy to do this, if there's any consolation in that.
It's a wonder the top didn't crack as it deflected upward!
If you even roughly calculate the pressure potential created by an air hose with a 120 PSI top end, the numbers get really scary. Even regulated down to 30 PSI, that's 900 lbs. spread over 30 square inches.
Compressed air can cause an amazing amount of damage, to people & pets as well as inanimate objects.
Many years ago, my father had to deal with a man in the ER who had a ruptured bowel caused by a co-worker in his machine shop messing around with an air nozzle. It's all fun and games.....
Thanks for posting. I can always use a reminder.

Sorry guys for the lack of response. Ok, I glued her up using some titebond, after cleaning off the old glue. I also added some little diamond jobbers to help support the fractures and it seems to be OK. Now here comes my next set of questions.....One should I mount the bridge with some bolts and put some strings on it to ensure that there isn't any hidden issues now with the top?....Now that I repaired the top lift I am not sure what I should do about the finish. I peeled back some finish to get a better eye at the damage and now I don't know if I should strip the top or give her another coat of vinyl sealer and build it back up with the clear? I also want to take this chance to say thank you guys for your help and comforting comments.

It will either be ok or u will have to do another top. Don't fret about it. keep moving. Really.