cerita red casting wax and floating scum

I melted some cerita red casting wax slowly to the proper temperature and
found a light brown scum full of bubbles floating on the top. I tried to
mix it in, but it rose to the top again, so I skimmed it off. The remaining
wax is free of bubbles and dark red. I like that because my waxes have
bubbles here and there and perhpaps that step will rid my waxes of bubbles.

Is that a mistake? I'm thinking that the scum is an additive necessary for
proper burn out or some such. Clearly I fractionated the wax in some wayby
heating. I hope the remaining wax will burn out properly. Am I alone here?

PW

On Sun, 30 Oct 2005 14:55:01 -0800, in hõ "Paul Wilson"
wrote:

I melted some cerita red casting wax slowly to the proper temperature and
found a light brown scum full of bubbles floating on the top. I tried to
mix it in, but it rose to the top again, so I skimmed it off. The remaining
wax is free of bubbles and dark red. I like that because my waxes have
bubbles here and there and perhpaps that step will rid my waxes of bubbles.

Is that a mistake? I'm thinking that the scum is an additive necessaryfor
proper burn out or some such. Clearly I fractionated the wax in some way by
heating. I hope the remaining wax will burn out properly. Am I alone here?

PW


I suspect you eliminated whatever residue might have remained in your waxpot,
or perhaps surface contamination on the wax from packaging, or from whatever
molds might have been used to form the wax chunks, if any. I doubt you
eliminated anything essential to the wax's performance. Some air bubbles are
common. I find most of the injection waxes I've used also need a bit of time to
just sit molten, for the air bubbles incorporated in manufacture, to fully rise
out. Since in the wax pot, they sit at the surface, well away from where the
injection nozzle taps the molten wax from the pot, I usually don't pay itmuch
attention.

Peter