I have been casting with Delft clay and have started running into
problems. The compacted strength of the clay is not what it used to
be and it is getting crumbly and I am having problems seperating
moulds (molds in the US). I have been using talc as a seperator on
all exposed areas.
Now, I suspect it may be:
a) A problem with trapped moisture in the clay as I quench the mould
in a bucket
b) general contamination - while taking care to remove the burnt
clay, there is always something, plus the talc gets in there too.
c) General change over time with repeated casting.
d) It has become too dry as it uses something like an oil as it’s
What I want is to rejuvinate it as on the whole, it seems fine and
it’s quite expensive and I’d like to get as much out of it as I can.
I was wondering if anyone had any ideas?
How about baking it in the oven to dry out the moisture? If it’s
crumbling perhaps adding some olive oil might make it sticky again?
Finally, has anyone tried lost wax casting with Delft clay? i.e.
make a wax model, melt it out in the kitchen oven? then refilling.
That way I could do items with undercuts. I haven’t tried it as I
thought it might be dangerous - especially if the wax was absorbed by
the clay rather than burning out and then exploded when silver was
Regards . . .