1150 Pottery Clay sealer?

by Rob Donaldson
(Peterborough, Cambs, UK)

1150 Pottery Clay sealer? Query: Hi Peter. I used to work for royal doulton and m.b.i/ coalport, wedgwood a few years ago and i still prefer working with 1150 but as i want to do silicone mould making would you or anyone else know of a good seal to paint or spray onto the leather hard figurine? i have used button polish but its a bit scary if you know what i mean. thank you, Rob Donaldson

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Reply by Peter (admin) to "Unfinished Piece 1150 Pottery Clay sealer" Query

Hi Rob

I'm back after the Xmas / New Year break. Sorry for the delay in replying. First I'd like to say what a bonus it is to hear from someone of your repute. When I was starting out (with Welsh Porcelain and Heredities etc) yours was one of the names talked about as one of the top men. I can see by your unfinished piece you have incredible skills. You reputation is well deserved. Hopefully, the top guys are all still making a good living form doing what they love. Feel free to email me anytime on any subject.

Now onto the 1150 pottery clay query. As far as I know, you don't need any sealer for 1150/silcone casting. At least, I have never heard that you do. Problem is, I am NOT one of those technical sculptors. I have always passed technical stuff like that onto specialists. However, I am friendly with a couple of top technicians, so I have emailed today and await a reply. Watch this space - I'll publish the reply in full right here asap.

Best regards

Peter (admin)

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Reply by George (technical adviser)

Re: silicone over pottery clay - no release is needed. Rob could coat the clay with shellac first but when you lay up the clay wall to create the first side, the clay wall usually does SOME damage to the (soft) original when you go to remove it - after you create the first side of the rubber mold - rubber and rigid mother mold - so if you DO coat the sculpture with shellac and it tears off when you remove the clay wall, ready to do the second side, it is near impossible to smooth out the clay in those areas and the silicone will pick up the micro-steps of the missing shellac.

George