On occasion, I have seen plastics pieces which I would like to
cast and later mold.
For example, recently, I have obtained a small birthday cake
ornament which I would like to cast, mold, etc.
How do you identify the correct plastics which can be used???
Will they preform as ‘lost wax’ does…
MORE IMPORTANT, WHICH SHOULD YOU STAY AWAY FROM???
Thanks, Jim R.
On occasion, I have seen plastics pieces which I would like to
cast and later mold.
For example, recently, I have obtained a small birthday cake
ornament which I would like to cast, mold, etc.
How do you identify the correct plastics which can be used???
Will they preform as ‘lost wax’ does…
MORE IMPORTANT, WHICH SHOULD YOU STAY AWAY FROM??? Thanks, Jim R.
Most plastics will burn out successfully. If transparent they
will do so well. Other plastics may contain inorgainic filler and
thus need to be sprued so that any ash or incombustible residue
can drain (or be blown out with a judicsious air blast thorugh
your sprue system).
Take a small piece of the plastic, place on a clean brick and
put a flame on it from a torch. When you are done if there is any
residue you need to provide good ash drainage in your spruing. If
there is no residue the plastic has a ‘flash point’ and may in
fact burn out almost instantaneously without residue. Some
plastics do well with extra long burnout cycles.
Charles
Brain Press
Box 1624, Ste M, Calgary, Alberta, T2P 2L7, Canada
Tel: 403-263-3955 Fax: 403-283-9053 Email: @Charles_Lewton-Brain
Metals info download web site: Learning Center - Ganoksin Jewelry Making Community
Product descriptions: http://www.ganoksin.com/kosana/brain/brain.htm
Links list hosted at the Metal Web News:
http://tbr.state.tn.us/~wgray/jewelry/jewelry-link.html
There Are 2 basic types of plastics: Thermoform, and thermoset.
The later will give you great grief if you try to do a burnout.
These are generally resins and epoxys. thermoform plastics (like
plastic bottles, model cars/airplanes) will behave just like wax
when burning out flasks, just be sure to use plenty of
ventillation.
Tim Goodwin