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Leaking plaster mold? Answered

Hi All,

I have a six-part plaster mold that leaks. It is so time consuming to make another one and I would like to fix it. During construction I  slightly over shaved some lines that during casting it leaks. I can use it but it creates more work.
Now I want to make a master mold from that but want to fix it first.
Does anyone know how to fix such problems on molds? I really appreciate the help.

Thanks and hope to hear




Best Answer 6 years ago

Make a putty like mixture of plaster of Paris with a 50/50 mix of water and white PVA glue. Apply like ordinary putty to fill in the low places and let it cure. It will bond to the old plaster and can be trimmed and sanded as necessary afterwards.

Dear Buff and Rick,

thank you for your prompt help.. I will try them today.
However do the mold needs to be soaked and fully wet before I do that

Thanks again


Or indeed seal the gaps with putty or play dough.