How thin could an aluminum casting be successfully casted with a plaster method?

Question

I'm starting a sculpture projects in which requires sections to be casted with molten aluminum. about .1 inches thin.
would it be possible? Is it fluid enough to flow through a "wire" form of a casting?

Answer 1

that depends how long the "wire" is and how much mass you have at the end of each wire.



I would think 1/8 of an inch feasible depending on the position of the feeds, so I guess you can do 1/10 as well, but it really depends on the geometry and size. You always can have more metal feeds, which means more cleanup. Depending what you have available there is always vacuum casting and centrifugal casting.



Keep in mind that the plaster needs to be perfectly dry and also preferably still hot.

Answer 2

The problem with going that thin with aluminum and plaster is that aluminum loses heat fast and plaster takes it fast, so for thin you want to heat the mold (actually all metal molds should be heated more or less) and plaster does starts to break down when heated as you approach about 900F.

I do not have direct experience with plaster and aluminum as I use investment with it, which is like plaster in some ways but is heated to prepare the mold and make it break up when dumped in water later. I am told that mixing silica flour (avoid breathing dust) with plaster, up to 50/50 makes molds that can be heated to fused glass temps (about 1500F) once. http://www.mikegigi.com/modeling.htm