|Sandstone Mold Question [message #58136] Fri, 07 December 2012 00:16 UTC
Pre-pologies if this is an old question. I did my best to search. I've got a large part I'd like to eventually cast in rubber/silicone.
Because it's so big, I'm thinking of the following technique:
1.)Print master "positive" in sandstone (for economic reasons)
2.)Create mold of positive using traditional RTV molding techniques
3.)Cast part in silicone.
I fully expected destruction of the sandstone master upon de-molding which would be fine, assuming the mold is successful. I'm imagining a pretty much total disintegration at that point...just so long as it holds up until the mold cures!
My question here is mostly whether anyone would caution against sandstone as a "positive" material for reasons other than its fragility.
Texture-wise, I'm actually hoping for a somewhat rough surface in the casting, so to me sandstone offers that built in
Any advice? Thanks in advance,
P.S. I'm also hoping to take advantage of the 15% off deal ending tonight, so fast answers will be much appreciated.