Hi David, I'm ngoing to answer below each of your questions
I just picked up a very inexpensive 6 ton hydraulic press. I know
it's not as spiffy or as powerful as a 20 ton Bonny Doon, but at
about 1/18th the price I'm willing to give it a try to see if it
meets my needs!
I think you'll quickly want a 20 tonner, because 6 isn't much when
you get into forming. You'll be able to puff simple shapes in thinner
metals, and possibly the 18g you want, but I suspect you'll run up
against the limitations of 6 tons very soon.
I make jewelry and smallish metal items out of copper, brass,
bronze or silver. Typically working in 24g to 18g. Want to be able
to press things up to 1/2" deep, but more typically, 1/8" to 1/4".
I've used a hydraulic press exactly once and with minimal
instruction. Urethane sheets are expensive and come in a variety of
"durometers". So, I have a few questions:
1. What "durometer" should I be aiming for?
In the Shore A scale, which is probably what Potter and Rio Grande
useautomatically without the distinction between Shore A and Shore D.
I just checked Rio's catalog and sure (shore ?) enough, they list the
urethane as the number followed by a small d, with the d standing
for 'durometer', but the urethane IS (Shore A scale) 85d, or Shore A
90d. I've bought pads from MSC Industrial Supply in the past, and
they will list it in a slightly different way, where the letter
after the number indicates the shore scale, NOT 'durometer. In MSC's
catalog, d will mean shore scale d, and a will mean scale a, so be
careful. Shore scale D is a harder range, so if you order '75d' from
MSC, it will be HARDER than the ' (shore A) 95d ' from Rio. If you go
to Potter USA, check with Kevin about this.
So (shore A assumed) I suggest getting 60 and 80 duro pads for your
setup. 95 is harder, and better for picking up surface detail (and
75d d-shore is even better but it takes more than 6 tons), but for
simple puffing 80 and 60 are going to work
2. How thick a sheet do I need to go 1/4" deep? 1/2" deep?
minimum would be 1/2" and 1", respectively, but the official line is
to use thicker, I believe.
3. Can I just stack two of the sheets I need for 1/4" deep to go
4. Good sources for inexpensive sheets of the above?
MSC, Potter, then Rio, lower to higher. Lee Marshall (original Bonny
Dooner) had 'the best'
5. What material do you usually make your pattern (dies?) out of?
Limited runs for me, so durability over 20 runs is not important
at the moment.
pattern dies.... pattern dies.... short runs.... brass, aluminum,
nylon, Lexan (not acrylic/plexiglas)e?
6. How thick does the die need to be get a 1/4" deep item out of
1/4" plus a hair