Thread: Australian made moulds

Originally Posted by John Doyle

I am still a little bit confused with this casting and stabilizing caper. Firstly some people seem to cast without pressurizing others seem to want to pressurize everything. It seems to me that it depends on the resin that is being used. ? Are there any hard and fast rules in relation to pressurising and cooking of the blanks. Obviously you cantcook in silicone moulds etc.. it seems to me that you have to do a few experiments and find out what suits you. Any comments or advice on these matters would be greatly appreciated. Cheers for now JD

Breifly John, Stabilising is using liquid compounds under vacuum , to draw the hardener into the material, mainly for softer and porous timbers to make them workable . After the vacuum is released ,they are wrapped in alfoil and baked to set the hardening agent . Normal casting with Polyurethane does not need pressure to work,some do use pressure to remove tiny air bubbles and set under pressure. Pressure casting is usually used to force the polyurethane into cracks and crannies such as pine cones banksia nuts worthless wood etc. So the type of casting you do is relevant to the materials ,for just plain ,or colored blanks ,no pressure is needed , at least this has been my experience with the casting processes . Cheers ~ John