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Old 12-16-2014, 04:17 PM
Andrew Werby Andrew Werby is offline
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Join Date: Dec 2005
Location: Oakland, CA
Posts: 647
Re: Sculpting with cement

Ditto what AD says about the salt. But a little clay's not a problem; most mortar mixes have some fireclay in them to impart plasticity. Sharp sand is best for building up directly; round sand flows better for casting. A little gypsum plaster will make the concrete "kick" faster, which can be helpful at times. I didn't know Hydrocal or Hydrostone contained Portland cement; if they do it can't be very much, since they act a lot more like plaster than concrete. USG's Gardenstone has quite a bit, so it lasts better outdoors.

Andrew Werby
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