plaster silica

[Dick]

HI all. I usually use r and r but the new forms will get so much cold working I can get by with plaster silica. I know mixes like r and r have a shelf life. How about plaster silica? does it matter if they are mixed or separate? I have an old bag of silica and would like to mix it with new plaster but would like some info first

thanks

[Don Burt]

I just used silica that's at least five years old with some new #1 pottery plaster, 50x50 and it set and dried nicely. The silica was stored in pretty stable conditions in a plastic bag.

[Don Burt]

Plaster relief molds

[Dick]

Thanks Don, I appreciate the info.

Dick

[Nikki ONeill]

Speaking of old plaster, I have a sealed box of C & R Loo MM 522 from 17 years ago, that I never got around to using (or opening). I have no idea what the mold mix is but would like to use it...part of finding and clearing out obsolete stuff and starting fresh. What else to do while hibernating? Does anyone remember back then? C R Loo is no longer, and I can't find anything about this MM on the internet. My R&R mixes are still good (tested 910 and 465), as are two plasters, olivenes, silicas, and Castalot. I'm jump starting getting back into casting, trying to stretch the mind a bit in a revived direction, and taking Richard Whitely's Coring Zoom class. . thank you for any insights.