toppy said:
texasSlick said:
comnoz said:
Aircraft type paint stripper will take it right off. Jim
Spray on gasket remover does a pretty good job too.
+1 Methylene Chloride is the active ingredient...look for a stripper that has maximum concentration of it. Clean up any residue with MEK
Slick
It seems you can get Methylene Chloride on its own (don't you just love ebay) but paint striper containing it is only for professional use and not to be sold unless you can provide prove of being professional user. So if i used neat Methylene Chloride would it remove paint better than modern paint stripper which is rubbish.
Hate to get off the titillating conduction, convection, radiation conversation, but after all, the thread is about powder coats and effective means of their removal.
With respect to methylene chloride-based paint removers, in the US these are as common and as near as the closest big box store. Here are links to strippers at Menards and Home depot, and the MSDS documents for the subject strippers showing they are methylene chloride-based.
http://www.menards.com/main/paint/c...fast-power-stripper-1-qt/p-1963283-c-8157.htm
http://www.menards.com/msds/101357_001.pdf
http://www.homedepot.com/p/Klean-St...-Stripper-QKS3/100180773?N=5yc1vZc5bmZ1z0t8la
http://www.homedepot.com/catalog/pdfImages/f8/f82aaef5-2d09-4054-bff0-da5949970222.pdf
Methylene chloride is an extremely volatile molecule, and as such, is often mixed with other polar molecules (alcohols, ketones, etc) and non-polar molecules (toluene, xylene, mineral spirits, etc) to reduce the volatility of the stripper so it remains on the painted surface for a longer period of time before evaporating, thus you don't see pure methylene chloride-based strippers. It's also a nasty molecule so be careful with it and use adequate ventilation when using.
Strippers function by either dissolving or swelling the paint film they are applied to. In the latter case, swelling the paint film ruptures the bond between the paint film and the surface it is attached to, thereby allowing removal. This is elementary stuff, but I mention it because there are many powder coats that are extremely difficult to remove because they are not readily swellable by the paint remover. There is not one powder coat out there, but rather myriad powder coats based on a wide variety of chemistries (epoxy, polyester, acrylic, nylons, silicone, and all conceivable hybrids thereof) and within each chemistry there are thermoplastic versions (powder particles fuse together with heat, but do not cure) and thermoset versions (powder particles fuse and chemically cure with heat). The former class is more easily removed, whereas the latter class is much more difficult to remove, because the solvent can not swell the cured coating. Swelling is inversely proportional to the degree of paint film cure (the cross-link density of the paint film), so the more cured the coating, the more difficult it is to swell.
In light of the foregoing, don't be surprised if you run into a powder coat that is very challenging if not impossible to remove with appropriate solvent-based strippers. A friend is redoing a Rotax engine right now and finding the only way to remove the factory powder coat on the cases is to bead blast it off. If you run into a tough paint removing situation and aren't in a hurry, slop up the part with stripper, bag it in a heavy plastic bag for days or weeks (let the solvent do the work, not you) and if the paint doesn't budge in a week, conclude it isn't swellable with your stripper and head for the bead blaster.
