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View Full Version : best paint that hot plastic won't stick to?



drcrash
09-11-2007, 09:40 AM
I'm looking for paint that I can use on a platen surface, for some small platens that won't see heavy use. (Or I'd cover them with metal.)

I'd like something smooth and durable that can take the heat and won't do anything funny. I want to be able to put tape on the platen and take it off without it peeling up, and to clean any residue off without damaging the paint.

I've read that some epoxies will outgas something that fogs some clear plastics (PETG?) when they get hot. Does anybody know anything about that? (I figure that I could probably fix that by postcuring the epoxy---maybe just leaving the platen in a hot car---but I'd like to avoid needing to do that.)

At the moment I'm leaning towards regular Krylon gray sandable primer in a rattle can, just because it seems to work fine on MDF-and-bondo tooling.
I'd prefer something glossy (very smooth) but that will probably do.

Any suggestions would be appreciated.

Paul

spektr
01-29-2008, 09:02 AM
GE Silicone II House caulking. Glob it on, smooth it out with a putty knofe. Good to at least 550 F. Scott

trophy
03-10-2008, 01:37 AM
I am bewildered as to why you want a smooth platen.
Can you tell us why?
I use MDF without any coating, it works fine.

High Seas
03-10-2008, 05:18 AM
First think that came to mind - Kiln Wash. It comes in various "grades/grits" and mixed with water. Badger (wide) brush and good to SEVERAL 1000 degrees. Used in ceramic mods and warm/fuzed glass molds. Its cheap and easy to apply and simple brush work to reapply.
Otherwise I'd post cure the epoxy - use your thermoforming oven - 200F for several (maybe up top 24) hours may do it - but thats off the back of my brain and I'd check the best post cure times before doing it too.
Interested in why the paint on platten?
:cheers: Jim

cod
03-18-2008, 01:37 PM
how bout enamel stove paint ?


or something I've been experimenting with is 100% silicone caulk, spread out on the platen by hand. Use rubber gloves wet with soap and water. The water will help neutralize the acid that the silicone is suspended in - hastening drying and allowing smooth application.

I know that silicone is considered a big no-no, but I hanvent had a problem with it- granted I'm not planning to try and paint any of my formed parts- I'm not sure if this particular silicone application would be a problem in that regard.

fatal-exception
03-18-2008, 06:14 PM
Krylon makes a glossy paint that's temperature and nitro fuel resistant. It's used on model airplanes. Most hobby shops carry it.

Paul

LeeWay
03-18-2008, 07:04 PM
Powder coating should do what you want. It outgasses as it's being cured, but then is pretty stable.
They also have high temp PC. I cure the normal stuff @ 400 degrees for 20 minutes.
The stuff you apply on headers though can take a bunch of heat.
Polycarbonate melts pretty high temp, but Pet G is much lower. Regular PC should handle Pet G with no trouble.