Injection wax recycling process

As a manufacture in the business for over 20 years I have seen
literally tones of spent injection wax in the form of defect wax
patterns, wax spill, over shoot waste and more. Today I called many
of my suppliers as well as an injection wax manufacture. And no one
has heard of or recommends any kind of recycling process or program.

Hmmm well we all know one reason why. If you recycle your old wax
patterns, that means you will be calling them less to order new wax.
Its an age old marketing technique. If you can get away with it why
not…

Is there anyone with a recycle program? And if not who of the wax
injection manufactures will step up to the plate and be the first to
implement a program or a process?

If your reply is : “Its not worth it” well it isn’t unless you make
it worth it. I could go into the how, why, and where. But I’d like to
hear some feed back.

Thank you,
JBF

Is there anyone with a recycle program? And if not who of the wax
injection manufactures will step up to the plate and be the first
to implement a program or a process? 

When I was in grad school (Tyler school of art in the late 80s), we
recycled the old or scrap injection wax by mixing it 50:50 with plain
microcrystaline wax. The latter is a softer, lower melting light
color, almost like beeswax in feel, though of petroleum origins. And
we’d also made an extruder, using a piece of pipe, a poured lead
“plunger” into the pipe, and a pipe cap drilled to accept plugs that
had various sized holes in them. Pretty simple. it fit into an
ordinary industrial type (the kind harbor freight sells for
straightening axels or similar things…) hydraulic press. To use it,
you’d put in a plug with the desired size hole, which you’d block
with a bit of paper towel. Then fill the extruder with the melted mix
of microcrystaline and used injection wax, leaving maybe a half inch
space unfilled. Allow to cool till the extruder is warm, not hot, to
the hand, and the wax inside, likewise is warm, not gooey. A few
strokes of the press handle then gives you lots and lots of sprue
wax. Since we also did some casting that was fairly large stuff, and
used center trees and the like, we had use for sprue wax up to about
3/8 inch in diameter, maybe more. The mix of microcrystaline and
injection wax gives a mix that is softer, more flexible, and melts
lower, than the straight injection wax, so it made great sprues.
Could be used as a sort of soft sculpture wax as well. As well, a
certain portion of the used injection wax was considered clean enough
to go back into the pot. The spills and drips especially were like
this, as well as bad heavier injections if they were made in molds
that had no mold release or powder to contaminate the wax. Some of
the silicone rubbers we used (the original contenti brown moldex was
one that comes to mind) worked quite well with no mold release at
all, if the mold was well cut and the parts not too complex, so those
injections would be good clean wax still, and incomplete ones could
go right back in the wax pot.

Peter Rowe