<html> <body> Wim - I'm sure there are a number of charts such as the one at the following link available: <a href="http://www.labsafety.com/refinfo/ezfacts/ezf164.htm" eudora="autourl">http://www.labsafety.com/refinfo/ezfacts/ezf164.htm</a> I like their catolog. The following chart refers to one type of acrylic, which is what keytops are made from: <a href="http://www.rothermelassociates.com/chemicals1.htm" eudora="autourl">http://www.rothermelassociates.com/chemicals1.htm</a> David Skolnik Hastings-on-Hudson At 12:08 PM 4/25/2003 -0400, you wrote: <blockquote type=cite class=cite cite>Melting Plastic, SOT, (Slightly Off Topic.) For hammer juice, I use acetone and keytops. I keep this solution in a plastic bottle. I'm no chemist, so how come the acetone dissolves the plastic keytops, but doesn't  dissolve the plastic bottle in which it is kept? Wim  PS. Before I get blasted for using this stuff in the first place. please be assured I use it very sparingly only on Steinway hammers when I voice. These Steinway hammers are first given a liberal dose of lacquer and lacquer thinner, as per factory specification. I don't use any kind of juice on other hammers. (I keep the lacquer mixture in a plastic bottle too, (a mustard bottle), and it doesn't dissolve either.) </blockquote></body> </html>