At 8:46 AM -0700 12/7/99, Wayde Allen wrote:
>On Mon, 6 Dec 1999, Pollmeier Klaus wrote:
>
>> harden and dry. You will then need lead plates ca. 3/4 to 1 cm thick. With
>> a press, that provides a pressure of ca. 500 kg per square centimeter, you
>> now press the relief into the lead.
>
>This is true if you restrict yourself to 19th century equipment and
>materials. However, someone on this list mentioned replacing the lead
>plates with a plastic casting resin. I don't remember who said that, but
>I thought is was a very clever idea. I don't suppose that the person who
>offered that idea is still here and would like to comment further?
>
>- Wayde
> (wallen@boulder.nist.gov)
Plastic casting resin is a good way to proceed. I worked with making
Woodburytype molds for several years using many such products originally
slated for various other applications from dental repair to bowling ball
materials. What needs to be used is a product that produces very little
heat in curing as too much heat will crack the gelatin relief. The other
main component must be a zero coefficient of expansion or contraction while
curing. I got some products to work well, and then the manufacturer would
alter the formulas. At this moment I don't know the name of the best
product out there to use. I hope this helps.
James Hajicek
School of Art
Arizona State University
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