Celluloid repair

[Dave Richard]

Not exactly a guitar question, but related: a friend plays and repairs accordions, the kind with the body covered in luscious various colors of celluloid. He asked me about repairing cracks or splits in the material on these instruments. I told him about the different solvent cements( ie as sold by Stewmac) for gluing celluloid, and cautioned him to 'try it on scrap' first. Anyone have other suggestions for experience with such repairs?

[Robbie Collins]

Weld-On melts the two sides together and usually requires filing and sanding to level and polish the seam. It is also difficult to get the glue only on the edge, even with good access.  When the edges melt the overall width of the material is reduced so he might need to melt some spare celluloid in acetone and use it as a filler.  Unless the cracks are structural the accordion may look better without repair. If he could get at it from the rear he could use celluloid cleats to hold it together and forego gluing the seams. Clamping the seam together while it dries would require ingenuity and it takes a day or two to fully harden.

[LARRY KLOSE]

For attaching celluloid to wood I like LMI's binding adhesive.  It's a contact type cement but without the heavy "rubber" component.  Easy to apply with a brush, cleans up with acetone and a great bond.  The label says it works well on any plastic to wood bond.  I don't know how it would work on cracks or splits but I don't see why it wouldn't work as well as DUCO or other solvent based celluloid cements although it won't melt the patch together with the original surrounding material.  One advantage is that it has no squeeze out when used as directed--apply to one surface, wait, attach.

I recently re-attached a Loar-style mandolin pickguard to it's ebony backing with the LMI adhesive and not only was it a better bond than the original DUCO (I think), with clamping it allowed me to flatten out a slight warp in the celluloid.  Works extremely well on loose binding repairs, also.

Larry

[Paul Verticchio]

Hi Dave.

If you're talking ONLY about cracks and the material is what we call Mother of Toilet Seat, have him try Acetone. That's what instrument makers use to soften the sheets of celluloid to allow them to conform to the instrument's shape.

I used it to repair a crack in the covering of an Oahu amp...or was it a Magnatone?. Anyway, the Acetone will turn the celluloid into a pudding that can be reshaped. Judicious application is the key word.

You gave him good advice about practicing on scrap.

Consulting an accordion repair form is also highly recommended.

Hope your friend is successful.

[Dave Richard]

Thank you all for the replies. I have sent my friend a link to this discussion.