Sanding down acetone damaged plastic

December 26, 2014 3:31 PM

I ruined a vintage celluloid ring by spilling acetone on it -- the finish is now rough and cloudy where the acetone ate into the plastic. Could this be repaired with sandpaper or similar, or should I consider it a lost cost?
posted by noxperpetua to Home & Garden (12 answers total)

I don't know a thing about celluloid, but if the choice is between throwing it out and trying a repair before throwing it out, you've got to try.

Other possibilities: smoothing with a hot knife or partially melting the plastic..unless it's the explosively flammable kind of celluloid, in which case be really careful.
posted by Sunburnt at 4:02 PM on December 26, 2014

Sandpaper is going to leave the surface cloudy even if it wasn't before.

If this is really important to you, I would suggest you visit a jeweler.
posted by Chocolate Pickle at 4:07 PM on December 26, 2014 [1 favorite]

Best answer: Before throwing it out (if there are no better suggestions, and if the jeweler gives up), I might try a thin layer of clear nailpolish.
posted by amtho at 4:21 PM on December 26, 2014 [2 favorites]

Best answer: I'd try getting a four or six sided nail buffer on it. Don't start too rough though. I use them to give silver a nice polish and get rid of small scratches so it may work on the plastic.
posted by Ranting Prophet of DOOM! at 5:36 PM on December 26, 2014 [2 favorites]

before giving it up as a lost cause you might try a plastic polish. the only one i have any very limited experience with is by Novus. (the Google will help here). i don't remember exactly what i used in on but i do remember that it worked.
posted by Conrad-Casserole at 5:50 PM on December 26, 2014 [1 favorite]

What about the plastic polish kits that they use to clear up fogged headlights on cars?
posted by slateyness at 6:35 PM on December 26, 2014

Agree that you could consult a jeweller. When I was in the plastics shop back in art school, we'd polish plastic with rouge and buffing wheels, the same as metal jewellery but with softer buffing wheels and slower speeds (after smoothing it with super fine wet sandpaper)
posted by bonobothegreat at 6:40 PM on December 26, 2014

You might also check fountain pen forums. Many old pens are celluloid and they might have repair advice there.
posted by oneear at 6:46 PM on December 26, 2014

I would try something very fine like the aforementioned polish for headlights. A home dig version is to use toothpaste which seems to have the right level of abrasive.
posted by koolkat at 2:37 AM on December 27, 2014

Celluloid is an extremely delicate type of plastic, especially as it ages. Acetone is a highly effective solvent for plastics. You couldn't have spilled anything much worse than acetone on the celluloid.

I agree with others that you should probably talk to a jeweler about restoration. I wouldn't try any sanding on your own unless the jeweler recommends it. If it's deemed ok, I suspect you'll have to use jewelers polish, rather than any sort of fine sandpaper.
posted by Thorzdad at 7:19 AM on December 27, 2014

Agree with Thorzdad except that you do need to start with sandpaper. If you start buffing a rough surface you'll just polish up all the bumps. Fine wet sandpaper will smooth the surface first and actually make polishing faster and easier.
posted by bonobothegreat at 8:15 AM on December 27, 2014 [1 favorite]

This may sound really weird but my nail shop uses a very fine abrasive polish cream with a buffer to put a shine on my nails when I don't have polish on them. Maybe something like that?
posted by tamitang at 10:28 AM on December 27, 2014