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Plaster/silica thickness??
Posted: Mon Feb 02, 2004 1:48 pm
by gthomson
Hi all,
What's a reasonable thickness for a plaster/silica mold? 10" plates and shallow bowls, that sort of thing.
TIA,
Glenn
Posted: Mon Feb 02, 2004 4:29 pm
by Tony Serviente
I usually aim for a pretty even 3/4". Less than that and I lose them in handling. I also try and keep the wall thickness as uniform as I can, to prevent uneven heating which the mold and glass does not like. I have not had a problem going thicker, it just wastes the plaster.
Posted: Mon Feb 16, 2004 1:54 pm
by gthomson
Thanks, Tony. I've made up some patterns to these numbers.
I've gone through the archive and settled on a simple 50/50 hydrocal white/230 flint blend. I'me assuming the water requirement is based on the plaster content and that the flint just goes along for the ride, right?
Cheers,
Glenn
Posted: Tue Feb 17, 2004 12:08 pm
by charlie holden
rdguy wrote:Thanks, Tony. I've made up some patterns to these numbers.
I've gone through the archive and settled on a simple 50/50 hydrocal white/230 flint blend. I'me assuming the water requirement is based on the plaster content and that the flint just goes along for the ride, right?
Cheers,
Glenn
The flint, (or silica), still has to get wet. I use a 1.75 to 1 ratio of premixed dry ingrediants to water by weight when I'm making strong, open faced molds. For softer plugs I go down to 1.65 to 1, dry to water.
ch
Posted: Tue Feb 17, 2004 1:13 pm
by gthomson
OK, thanks, Charlie
Glenn