How to remove cork residue?

[Rob Gerety]

I have a teens Gibson A. Original finish. I have been using an arm rest clamped to the rim mostly to protect against my arm sweat damaging the finish. I like it quite a bit. I removed it the other day. When I removed it the surface of the cork pad on the bottom part of the clamp stuck to the back of the mandolin. The cork pad basically split - top part stuck to the mandolin. Bottom part stuck to the clamp where it is glued.

I was able to remove most of the cork stuck to the mandolin with careful use of my fingernail. But, there is rough area remaining. I cannot be sure whether it is residual cork from the pad or whether is actual minor damage to the finish.

Any suggestions how to try to remove this? Is there a solvent that would dissolve the cork material but not the finish? Should I just live with it and replace the pad with leather which worked fine on the top part of the clamp?

[lenf12]

Try a bit of lighter fluid or naptha on a soft cotten rag. Should work like a charm!

Len B.
Clearwater, FL

[Paul Hostetter]

The old Gibson spirit varnish finishes soften with heat, and it's very likely the impression of the cork texture is there for keeps. I wouldn't advise reheating it to smooth it out, needless to say, and there's no solvent that'll do much to soften it. If there were, I still wouldn't try it at home. One could (providing one had the skill) French polish over it and build it a bit until it was level.

My 1917 A spent a long session in 100 degree heat (in the shade) once and after the last note was played, I found my tee shirt welded to the finish on the back. That weave is still in evidence.

Before naphtha, I’d try water or something like Simple Green to get any remaining cork particles and adhesive munge off. Naphtha can't hurt either.

[Rob Gerety]

I've done nothing yet. But I can report this. The clamp has two sides, obviously. Once side (the bottom) had a cork pad about 2 inches long. The other side (the top) had a leather pad about 4 or 5 inches long. On the leather side there was zero problem. The problem only appears on the cork side. Looking at my mandolin closely the area underneath the original pick guard clamp looks and feels very similar to the area under the armrest clamp.

I will try the suggestions - but I think this is probably permanent. Given the damage I am sure I would cause with my sweaty forearm resting on the top without the arm rest I guess using an arm rest is a decent trade off? I wonder if the bottom pad had been leather would same thing have occurred?

[Paul Hostetter]

The cork absorbs moisture, and it's also more inconsistent in its structure. Makes sense that the leather side worked better. The stuff synthetic wine corks are made of is better than either: no chemical reaction, no moisture or sweat absorption. I make violin chinrest pads out of that all the time. There's still nothing you can do about the old Gibson finish that softens so easily with heat.

[Greg Mirken]

The stuff synthetic wine corks are made of is better than either: no chemical reaction, no moisture or sweat absorption.

Thanks for a great idea, Paul.

[Rob Grant]

With an FP finish, if it's thick enough, you can lightly buff the mark out with a bit of 0000 steel wool and then polish with something like Meguiar's #7.

Of course, the steel wool will actually remove finish, so it is possible to go down to the wood. If this is the case then you'll want to bone up on how to apply and repair French polish...not really a difficult process to get a basic handle on.