Kurt - I found the material described on Polymeric Systems web site. This is the same company that makes Duro or Kneadatite/Greenstuff. The formulation of Quikplastik is based on the same chemical activator:resin as Kneadatite, bisphenol a + epoxy resin. I only have guesses about why it didn't harden correctly. (1) Old materials that were on the shelf a long time? (2) Cool temperatures when you put the two parts together? As Janne says, a moderate amount of heat speeds up the chemical reaction. A lot of the sculptors use heat lamps, toaster ovens, etc. I use an old Crock Pot. Don't try a microwave oven unless you are interested in converting the interior of your microwave oven into ugly modern art.
(3) An olefin based material which slowed down the reaction. Was there any polyethylene or polypropylene on the surface you repaired? (4) Some kind of glue or adhesive under the 2 part putty?
Sorry I can't help more. Incidentally - the company materials show and talk about handling this without gloves. If you are going to use it once or twice and wash up thoroughly afterwards, that's probably OK, but if you are using any 2 part resin with a chemical activator every week (like me!) use thin rubber gloves and use it with good ventilation. The activator chemicals in 2 part putties are allergic sensitizers and will cause dermatitis, etc. Keep your putty-covered hands or gloves out of your eyes also.
All the best,
Dan
