styrene burnout tips?

I, like many of you I'm sure, have experimented with casting all kids of
stuff: insects, plants, small fish and lizards, etc. , but I don't have
much experience in plastics. I assume that there are types of plastics that
are not at all suited for this, ie: leftover soot, cinders or ashes, gas
formation
problems, etc.

Does anyone have any experience with the burnout (for lost wax casting) of
"hobby" type extruded styrene strips and forms as you will see he
http://www2.towerhobbies.com/cgi-bin...?&I=LXDYB9&P=7

.....or any other types of plastic that you've found "burn-outable" (or not).

Thanks for any and all tips or personal experiences

BR

vj found this in rec.crafts.jewelry, from "br"
:

]....or any other types of plastic that you've found "burn-outable" (or not).

generally, we don't try to burnout ANY type of plastic.
the dangers are just too great to worry about!


--
@vicki [SnuggleWench]
(Books) http://www.booksnbytes.com
(Jewelry) http://www.vickijean.com/new.html
(Metalsmithing) http://www.snugglewench.com
yahooID: vjean95967
-----------
"Only Irish coffee provides in a single glass all four essential
food groups: alcohol, caffeine, sugar, and fat." -- Alex Levine

On Sun, 02 Jan 2005 06:28:44 GMT, in rec.crafts.jewelry "br"
wrote:

I, like many of you I'm sure, have experimented with casting all kids of
stuff: insects, plants, small fish and lizards, etc. , but I don't have
much experience in plastics. I assume that there are types of plastics that
are not at all suited for this, ie: leftover soot, cinders or ashes, gas
formation
problems, etc.

Does anyone have any experience with the burnout (for lost wax casting) of
"hobby" type extruded styrene strips and forms as you will see he
http://www2.towerhobbies.com/cgi-bin...?&I=LXDYB9&P=7

....or any other types of plastic that you've found "burn-outable" (or not).

Thanks for any and all tips or personal experiences

BR

None of the plastics I've tried burned out quite as easily and well as waxes,
but I did have decent results with styrenes from plastic models. Often there
would be a little more ash, and the castings often had a slight
discolored/yellowish film on them that took a bit more cleaning/pickling. But
overall, they worked. So does plexiglass, which I've sometimes used in place of
wax when I needed to be able to carve or machine highly precise parts. In both
cases. I'd double the amount of time the burnout ran at it's high temp, and make
sure that this was right at 1350F, to insure complete burnout. The main issue
is that plastics in general produce more waste gasses when burning out, and they
are considerably more toxic. So before doing any plastic burnout, examine the
ventillation system you have in place that can remove burnout/combusition gasses
to the outside rather than allowing them to stay in your workspace. It need not
be complex. Mostly, I was doing it in summer months, and placing the burnout
kiln under a window fitted with a good exhaust fan proved effective. In another
instance, in the shop I worked in during the 90s, the burnout kilns were placed
under kitchen exhaust hoods that also effectively kept the toxic gasses from
remaining in the shop, plus we were using programmable furnaces that allowed the
burnouts to proceed overnight while we were gone, again reducing risks of
exposure. In my current shop, I'd probably not do it, as the venting is a lot
poorer.

Peter Rowe