S 100 74 restoration project

[SFIV1967]

I wondered if very, very gentle heat between two metal plates over a long period of time would flatten it with a minimum of shrinkage.

I'd think any warm temperature is bad for celluloid and it would only shrink even more. I think you have to try to cold press it flat between two flat wooden boards and leave it there for a couple of days or better weeks. I might be wrong, you would have to ask somebody who understands old celluloid, I just understood that starting at 60 deg C (140 F) celluloid can already start such decomposing process.
By the way, I got such an overlay from the same seller I think, I keep it between two wooden boards for almost 2 years now as I had no time to do the restoration yet it is intended for. My one was at least flat when it arrived.

Ralf

 

[Ppolfeldt]

I'd think any warm temperature is bad for celluloid and it would only shrink even more. I think you have to try to cold press it flat between two flat wooden boards and leave it there for a couple of days or better weeks. I might be wrong, you would have to ask somebody who understands old celluloid, I just understood that starting at 60 deg C (140 F) celluloid can already start such decomposing process.
By the way, I got such an overlay from the same seller I think, I keep it between two wooden boards for almost 2 years now as I had no time to do the restoration yet it is intended for. My one was at least flat when it arrived.

Ralf

Hi Ralf,
Thanks for your caution and tips.
This "curly" piece of celluloid was a gift, so I´m just happy someone took the trouble to contact me after seeing this thread, and the trouble to mail it to me. I fixed the headstock with a sticker that looks the part prior to having this option. We´ll see what I'll d o, but the "two year" cold-squeeze is definitely an option.

 

[chazmo]

I'll be very interested to know if you can actually fix that overlay. I think that the celluloid actually warps due to "outgassing" over time, and I think that's a permanent alteration to the material. But, hey... Give it a shot, Ppolfeldt. I certainly would. Patience is a virtue!

 

[SFIV1967]

We´ll see what I'll d o, but the "two year" cold-squeeze is definitely an option.

The "two year" was simply the time I have my one already between two boards as I had no time yet fixing the headstock. I don't want to take a risk having it somewhere where it might start to curl. So in your case I guess after a few days, maybe weeks you would already see if the celluloid can be flattened at all. Also probably you have to go little steps in pressing it flat in order to not break it. Like tightning the two boards every day 3/64" or so until you have it clampled flat. (or putting a few books on it and increase the weight of the books day by day a little bit).

Ralf

 

[Ppolfeldt]

New pickguard finally, way too costly, but well made by Chandler music.
Homemade oak frames to be finally shaped and colored…
Gettin’ there…

 

[Ppolfeldt]

No money.
Time to sell the guitar. I’ll post a few pics with sell- ready guitar..