How Can You Fix The Bubbly Mess That Occurs When Nitro Meets Rubber?

A pro-level fix will require sanding, filing, sealing, restaining or painting, numerous clearcoats, and buffing. Surprisingly labor intensive for what seems like a small fix. Not sure what luthiers would charge, I'm sure it can vary quite a bit.

If you're interested in doing a quick and dirty fix yourself, get a couple of grades of dry sand paper, maybe 250, 400 and 1000. Sand VERY lightly, especially with the heavier grades, until it's smooth.

If it's down to the wood: Apply a little sealer, sand off lightly. Touch up with stain or paint as appropriate. If paint, you may need to apply a couple of coats, and lightly wet sanding between (1000 grade). Then spray several coats of clearcoat, very lightly wet sanding in between (1600 grade). Let dry at least a week. Buff up with Meguiars or similar.

If it's not down to the wood: Jump to the part where you spray several coats of clearcoat, very lightly wet sanding in between (1600 grade). Let dry at least a week. Buff up with Meguiars or similar.

How much time you put into sanding and respraying will determine how well it comes out. Other guys who have done this might have other finishing schedules. Many ways to skin the cat here.

Note: Any sealers, paints or clearcoats you use must be nitro or nitro compatible. Get them from either Stew-Mac or Guitar Reranch if you're not sure your local hardware store carries the right stuff.

 

You MUST get rid of all the affected lacquer, right down to the wood. The problem is that plasticiser from the rubber (neoprene, not real rubber) has 'migrated' into the nitro. It can't be removed, dried out, cured or fixed in any way unfortunately. If you don't remove all the contaminated lacquer, the plasticiser will simply spread back into the new finish.

Luckily new nitro blends very well with old (precisely because it never quite permanently hardens, which is why this problem occurs in the first place) and you should be able to repair the damage fairly invisibly if you're lucky, depending on the finish colour.

Last year I saw two Custom Shop Gibsons - a Historic ES295, and a Catalina Les Paul - ruined like this by being left on neoprene A-frame stands... in a shop . Each one had two 'stripes' across the body edge and a huge spot in the middle of the back. Very hard to fix in those sorts of colors.