Warped archtop guitar pickguard

[Eric Adler]

Does anyone have any experience in flattening a warped pickguard on an archtop guitar? I think the pickguard is celluloid.

[Jim Bancroft]

I can't say I have ever done this, but I'd probably try it if I needed to flatten one.

Take a large pan of water, big enough so that the pickguard easily fits in it.
Heat the water to boiling or near boiling, immerse the pickguard until it gets flexible, remove and quickly clamp between a couple scrap 3/4" thick boards. Or, you could possible bend the warped spot until it cools and hardens, which is just a few seconds. Wear gloves.
Being I have never tried it, this is only an idea that I think will work without cracking or damaging the guard.

Jim

[Eric Adler]

I decided to try something somewhat similar. I sandwiched the pickguard between two pieces of glass and placed this into the bottom of a metal roasting pan. Then I placed weights on top of the glass until the pickguard was flat and poured boiling water over this until the "sandwich" was immersed. When the water cooled to room temperature, I removed the pickguard. The result is much flatter than before the treatment, although there is a slight bow remaining.