I was curious about using green soap tincture to reduce surface
tension on wax models so I dipped my wax models just before filling
the flask and it went pretty badly.
After casting there was a very black and crusty-distorted surface.
After this disaster, I checked the bottle and it says "Green Soap,
and Ethyl alcohol 30%… purified water, and my current suspect.
So was it the lavender oil that did not burn out and I assume there
are green soap tinctures that are pure without the lavender oil? I
didn’t have much bubbles to begin with on my castings so far so I
may just abandon this idea unless someone can share what brand they
use. Or do people make their own?
I did a standard 5 hour burn out for a small flask.
The brand is called “Cosco” and it seemed to be very basic green
soap for hospital cleaning. I wish they put the words “scented” on
there so I would have known it was not pure green soap.
Forgot to mention I don’t use vacuum assisted casting or
debubblizing at this time, would love to build that next though. It’s
definitely worth it and relatively simple to build a debubblizing
table. As soon as I have time off I will build one for the next
project. I’m currently building a shop press and will put the
debubblizer for the next task.
When I vibrate the investment before pouring and then vibrate the
filled flask when using Satin Cast I’m getting only a few bubbles
every now and then, just wanted to try the green soap method to see
how close I can get my castings to near perfection with my current
I will try the dishsoap method next since the purchased green soap I
see has additives that don’t burn out.
Kathy- Even if you sonic off the cornstarch you may still have a
slightly textured surface. I find that if I use too much parting
powder aka talc or cornstarch that the texture is imbedded in the
wax surface. I find that if I chill my molds a little between
injections that I don’t need as much parting powder or silicone spray
to get my waxes to come out. We have a small upright freezer in our
basement studio that I use.
Use the sonic to get your excess cornstarch off but just be sure to
rinse it with water after so that what ever is in your sonic doesn’t
react with the investment.
A few drops of washing up liquid in distilled water is all you need,
dont use neat or you will get a carbon residue. Just dip your wax
tree and let it dry before investing.
Debubling the investment is much better, you can vacuum deair it
using a small hand pump used by garages for setting carburettors and
a desiccator. Then pour carefully and tap the flask to remove any air
you may have introduced by the pouring. Never pour the investment on
to the wax, always into the bottom of the flask and let the level
rise. Alternataively you will have to debubble after pouring by
using a vibrating table or a lot of tapping on the flask. the latter
is always the last choice as you may dislodge your waxes with
disastrous results if centrifugal casting.
Would this work to get cornstarch off of waxes? I have some fussy
molds that *must* be powered or I can't get the waxes out.
Have you tried silicone mold release spray? I find it leaves waxes
with a much better surface than talc or cornstarch, and makes the
molds release the waxes very nicely. One touch is to very rarely
powder the molds, taking care to get a little of the powder into any
vent cuts in the rubber. Then throw out the first couple waxes. This
cleans the mold cavity of the powder, but leaves traces of the powder
in the vents, allowing them to better aid in getting air out of the
way of the incoming wax. then a light spray with silicone to help
release the waxes from the mold. Doesn’t need spraying before every
wax, just when it starts to stick again (several waxes. how many
depends on the mold and the type of wax, and the wax temp).
The other issue could be that investment, if not mixed up near the
time of gloss off (8minutes ish) will sperate back to solid and
water. I didn’t look at the pic before, it looks more like the water
streaks I get if I rush the process and the flask sat too long
before it sets up. Need to be mixed more near to time of pouring. Use
some debubbleizer and you should be good. It is a bit dark as someone
mentioned which is to short a time or insufficient temp. Good luck