Stinky wax

[Peter Angel]

I was doing some lost wax kiln casting and there must have been a some victory brown wax residue left inside the mold.

There was only a tiny amount of wax residue but the fumes were so smelly! It absolutely stank. I had to switch off the kiln.

Has anyone used natural beeswax for last wax casting? Is it less smelly than victory brown?

Peter

[Morganica]

Victory brown is a petroleum-based wax and its combustion products are supposed to be toxic. I know if I burn out even small amounts of victory brown I must do it with as much ventilation as possible. Otherwise, the smoke that fills the studio is extremely acrid and makes it difficult to breathe. It also leaves crud all over the place and gives white walls a kind of mustard-like glaze. (So I'm pretty good about steaming it out or otherwise getting rid of most all the wax before the mold goes in the kiln.)

I don't think I've ever tried to burn out pure beeswax in the kiln, but I have burned out "wax bondo," a mix I make with 50% lard and 50% beeswax melted together. I use it to fill in gaps between a glass inclusion (or a faulty casting) so I can build another mold and refire. Bondo also produces fumes and a brown, oily smoke that can stain, but it's nowhere near as obnoxious as victory brown. It will burn out pretty cleanly; if you use a lot of it in a mold the glass will develop a grey-brown oily ash that can be wiped or scrubbed away.

Beeswax isn't cheap; it might be rather expensive to do the whole model in beeswax, and you'd probably want to be diligent about reclaiming as much as possible. I'd also think about how I was building the model--if you do a lot of wax carving/shaping outside of simply pouring it into a mold, beeswax isn't as effective as waxes made especially for that.

At some point I want to do some testing with soy-based waxes. If they're solely of organic materials they should burn out in the kiln, so they might also be an option.

[Peter Angel]

I have burned out "wax bondo," a mix I make with 50% lard and 50% beeswax melted together.

Cythnia, Are you able to steam out the wax bondo from the investment mold? Also, does the unused portion go bad because of the Lard?

Pete

[Morganica]

I've never had it go bad; it's a kind of soft, waxy, pale yellow mass that feels a bit like butter but doesn't melt so fast. It's fairly hardish at room temperature but goes soft with any kind of handling. I generally have to chill it in the freezer for a few minutes to be able to harden and polish it.

And I don't steam it out at all--usually it's between the glass and the mold itself so there would be no way to steam it out. I'll use it, for example, when model+mold+reservoir are too big for my kiln. I'll divide the model into multiple parts at unobtrusive spots, cast each separately, and coldwork the pieces down to final form. Then I join them with wax bondo, chill them until the bondo is hard and smooth it down so it's seamless and polished.

At that point I can encase the whole assembly in refractory, with a tiny reservoir at each of the join points for a little additional glass to fill the gap. It now fits in the kiln, and I fire it. The bondo burns out almost perfectly clean, usually deposits that oily brown fine ash on the surface but it's easy to remove.

http://www.morganica.com/bloggery/2009/ ... dio-needs/

[S.TImmerman]

Just what I was looking for! For my first lost wax project what is the best wax to buy? i want to burn it out. It will be a fairly small project - I made a flexible mold and used glass powders but it fell in the kiln =producing a flat blossom -I need to add a little dark paint in the whorl of stamens in the center of the poppies.

I will be using Castalot and need a good wax, would beeswax be best? these are about 2 inches

Thank you

[S.TImmerman]

Is it 1/2 and 1/2? Beeswax and para-wax?