Any know if you can zinc into rtv rubber moulds ? Also could epoxie be
cast into the same mould later on ? What kind of life does the mould
have ? Doo i need parting powder?
What kind of foam is used for lost foam casting? All the foam ive seen
has pours , any way to seal them up?

"aws" wrote in message
...
Any know if you can zinc into rtv rubber moulds ? Also could epoxie be
cast into the same mould later on ? What kind of life does the mould
have ? Doo i need parting powder?
What kind of foam is used for lost foam casting? All the foam ive seen
has pours , any way to seal them up?
^^^^^^^^^^^^^^^^^^^^^^^
Since noone has responded, perhaps a glossary of terms would help:

Moulds = molds
Epoxie = epoxy
Doo = do
i = I
ive = I've
pours = pores

Hope this helps. G

"Leo Lichtman" wrote in message
...

"aws" wrote in message
...
Any know if you can zinc into rtv rubber moulds ?

Zinc is cast in rubber molds all the time in spincasting. But the silicone
used for that is not common household RTV. It's a very hard composition made
for the purpose.

Also could epoxie be
cast into the same mould later on ? What kind of life does the mould
have ?

'Don't know if you can successfully cast epoxy after using a mold for zinc.
The zinc is a little rough on the surface of the mold, but it will last for
hundreds of shots. There even are higher-temp compositions that will allow a
few shots of aluminum.

Doo i need parting powder?

For epoxy, not with silicone. For zinc, you'll have to look it up. Try
searching on "spincasting."

What kind of foam is used for lost foam casting? All the foam ive seen
has pours , any way to seal them up?

^^^^^^^^^^^^^^^^^^^^^^^
Since noone has responded, perhaps a glossary of terms would help:

Moulds = molds
Epoxie = epoxy
Doo = do
i = I
ive = I've
pours = pores

Hope this helps. G

"aws" wrote in message
...
Any know if you can zinc into rtv rubber moulds ? Also could epoxie be
cast into the same mould later on ? What kind of life does the mould
have ? Doo i need parting powder?
What kind of foam is used for lost foam casting? All the foam ive seen
has pours , any way to seal them up?

Yes, zinc can be cast in rtv. You might want to use a
lower melting point zinc like ZA8 to extend the life
of the mold. Rio Grande www.riogrande.com sells
a high temperature RTV that can handle temperatures
to 1100 degrees F.

You might want to contact customer service for the
RTV you plan on using to see if it's compatable with
the resin you plan to use.

No parting dust is needed, however, mica or graphite
will likely be needed.

We prefer white beadboard for lost wax casting. The
blue and pink high density insulation is likely to have
fire retardents. We like low melting sprue wax to seal
the holes. My projects page has a couple of demos
about hot wire cutters and casting zinc with styrofoam
www.granthams.com/Projects .

Rod

chips-'n-swarf wrote:

We prefer white beadboard for lost wax casting. The
blue and pink high density insulation is likely to have
fire retardents. We like low melting sprue wax to seal
the holes. My projects page has a couple of demos
about hot wire cutters and casting zinc with styrofoam
www.granthams.com/Projects .
When Rick Chownyk did some lost foam pours at the 2007 CNC
Workshop, the foam exploded in HUGE billows of black smoke and
plenty of orange flames. It looked just like awful hollywood
movie pyrotechnics. If there are fire retardants in it, they
were no match for 800+ F aluminum.

Jon