When I was studying repousse at Cerritos College, we mixed pitch with
Plaster of Paris to add body and lard to soften the pitch. We made
the hemispherical pitch bowls and regardless of the weather the pitch
does not cold-flow off the edges of the bowl.
I have removed pitch from the bowls by chucking the bowl in my bench
vise on end and used a heat-gun to melt the pitch into an aluminum
pan underneath it.
Avoid using a torch on the pitch as it can ruin the pitch, ignite and
can give you a really bad burn, it sticks to the skin, and does not
cool for what seems like hours and takes the skin with it when it
I got tired of making a winter and a summer bowl by melting and
reformulating the pitch twice a year so I bought several bowls and
just formulated hard and soft bowls.
We filled the bowl with lead wheel weights, melted in the bowl so the
steel clips were extracted. The bowls were filled to within an inch
of the top for weight and stability. Then the pitch was added.
The class was a year long activity with a lot of time spent making
the Japanese style chasing and repousse tools and hammers. Check the
Internet “MENUKE” to see some of the Japanese style of repousse.
Bill in Vista