Do I need to seal an unkilned clay original before putting silicone on it to make a mould?
It is possible dependant upon scale of the work, try sealing it in a undiluted pva glue this will provide some protection against the odd knock however you must apply this when the clay has started to dry out not when wet and once you have sealed it you will not be able to fire it, putting a covering of any sealant upon an unfired medium will cause water retention in the clay when you come to fire it it will blow i take it that you are going to make a plaster cast mold,then if you are i use a covering of dental mix its a kind of substance that dental techs use to make impressions for false teeth,it goes off pretty quick then apply the molding plaster over the top this gives you a colour change so when you come to seperate and remove the wet clay you can see were the plaster begins the clay starts its never failed me yet.
