Metal Casting Zone

Hi,

New to the forum, and new to the lost wax process. Go big or go home is sort of a motto of mine, so my first attempted casting is going to be a lion I've sculpted out of clay. I haven't made the mold, or the wax copy, etc., but I'm trying to get all my ducks in a row before getting to that point.

I'll be casting in bronze, and I'm planning on using drywall compound for the investment (it is what I have lying around...trying not to spend any more money than I have to). I've got very fine masonry sand that I'll sprinkle on in between investment coats. For a kiln I'm planning on using my casting furnace, which runs off of waste oil (see www.backyardmetalcasting.com ). I figure I can do some quick modifications to make it be able to drain out wax.

My question is about how long I should fire the mold. Just until the wax is completely out? Is there a recommended length of measurable time?

Also, what is a good budget wax? Something that'll capture detail, etc.

Thanks

I've tried a couple types of wax, pure parrafin breaks apart too easily. I mainly use pure beeswax or beeswax with some sterine hardner in it. As for burnout time, the only thing I can say is longer and hotter than I did. Instructions call for a heat up time to melt out the wax and then ramp it on up to around 1200 F, hold it there for a time and then pour the metal in while the mold is hot.

I am using investment for the compound ( dry wall compound is i good idea i will have to try that !

the wax however i have been using ordinary candle wax from the doller store. i melt it down in a crock pot and pore into the rubber molds. I got the odd air bubble or imperfection but touch them up later ( im casting beaver figures for a fire engine bell)

the burn out i do is at 450 deg C ( im canadian ) and bun it out for about 2-3 hours in the kiln. i know it is done when it is has gone white again . it will first turn black and maby a bit of fire will brake out depending on how well you melted out the wax in the crock pot.