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I've got a plywood topped guitar with the bridge coming off in the shop. When I removed the bridge it was apparent a large portion of the top layer of plywood came off with the bridge. It actually seems more like a thin veneer than it does a substantial layer of wood. I'm not sure if that's normal? Anyway I cleaned finish off of the perimeter and it looks like it should be straightforward from here on out, but was wondering if there's any reason to feel hesitant about getting good adhesion once its cleaned up?

Epoxy is your friend.

New username, same Pat Mac

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Pat

I've had adhesion issues with epoxy (Sys III) on some Chinese plywood tops.

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Steve Smith
"Music is what feelings sound like"

Another thought occurs to me, should I worry about the fact that this new surface has the grain oriented opposite from how it would normally be oriented? I imagine the grain running parallel to the bridge would be a little weak with the torque of the strings?

Conor

I think with the enough epoxy in there it shouldn't matter, however you could put a piece of veneer or something the right thickness in there. Epoxy thoroughly slathered all around of course.

New username, same Pat Mac

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Pat

If you use epoxy please put a label inside stating this and leave your info so I can make sure it comes back to you for the next reglue! May as well use CA if your going to epoxy it and be don in 5 minutes instead of 24 hours....

I typically leave the layer of top wood on the bridge and as long as there is a haze of that spruce left on the center ply wood glue will work well and the wood grains lock right back together. Attention when removing these will help avoid this situation.... I typically charge extra for bridge re-sets on laminate tops for this reason.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

LoL! My standard guarantee in that situation is "I guarantee you that sucker's not comin off!"

Good advice about leaving the wood on the bottom of the bridge.

New username, same Pat Mac

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Pat

The was a classical guitar that had a bridge fail and was "repaired" with some sort of epoxy. It failed a second time. I charged an extra half hour of labor getting that crap off so I could glue it porperly.

Good to know Brian. To take into consideration the plywood top never occurred to me at the beginning. It will from now on that's for sure.

Well, I had "cleaned" up what I thought was mostly finish with some wood fiber attached to it, so there isn't a lot of the original wood fiber from the top layer left. It is very clean now though. It did seem like maybe this bridge had been re-glued before, there were gobs of clear glue all over the bottom of the bridge, it looked like somebody ran a thin bead of clear silicone all over the bottom of the bridge. I don't like the idea of using epoxy, as I feel I'd rather not create any more of a situation that can't be undone. I'm having a hard time telling if the center wood is actually bare wood or if it still has glue from the lamination all over it. On a solid top guitar I'd just be gluing at this point...

Any thoughts?

I can't imagine a plywood top guitar with a popped bridge could be worth more than $50. A quickie epoxy glue and even just an ultra basic set up it's going to be that much. I've only done a few like this, and they were usually some kind of sentimental guitar.

New username, same Pat Mac

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Pat

I suspect this guitar falls into the category of inexpensive offshore guitars that people pay $450 at the store for, they look overly fancy, and 10 years later the customer remembers paying $1000 for it, which is an exorbitant amount of money to pay for a "guitar"...

Another luthier I talked to suggested that very rarely (he said maybe 1 in 75) he'll put a couple machine screws through the bridge and then cover them with a pearloid or wood dot if he feels like the bridge really needs the extra insurance...

I usually put screws, washers and nuts through the bridge and top. Then put a wood plug covering the screws. It’s the only way to be 100% sure it will hold.


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Damit Jim, I'm a doctor, not a luthier!

New username, same Pat Mac

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Pat

I don't see anything wrong with epoxying a cheap guitar back together either. Having said that Titebond is some pretty incredible stuff and is forgiving too. I usually just sand and scrape everything back, sometimes you go through the cheap ply's but who cares. It looked like you did a good job cleaning it up, I would use Titebond on that.