Yeah, the R&G ResinL + GL2 will fully cure at 20c, but it takes a while(by design)... i've tried to demould casts after 48 hours and that is too fast, it's still not "crisp"... the tests i've done with demoulding after 3-5 days works a lot better... the consultant i talked to at R&G also said that they'd recommend start postcuring after around 4 days...
/Thomas