There are a couple of brands of vinyl molding compound on the market, Gelflex from Bayer, and another called Vinamold. I've no experience with Vinamold, but I've used Gelflex. There are three grades, ranging in melt temperature from 130° to 155°. The material can be cleaned, cut up and remelted when the mold gets a bit ragged, so it's more economical than RTV silicone compounds. I can see two uses for reprap: to RP a casting mold, which would help make reprap more "rapid" than 15cm³ deposition is, or as a support material for a two head version. Current plastics used would melt it locally and stick, but when they've both cooled, they'll separate easily. The only drawback I can think of is that it's a gel and might be hard to persuade to melt through a nozzle.
Murray
