Metal Casting Zone

So the next question is this... If I were to add crushed pumice (lava rock to the clay/sand refractory mixture. would it act more as insulator and take the higher tempratures of the bronze melting tempratures? I was once in a volcano so it can take the heat? Also is refractory a "wear item" that eventually Ill be chipping it out of the shell and recasting it with new every 100 pours or so, or is it the more you abuse it with cast iron temps the faster it breaks down or "C" all of the above.

It varies according to temp and the refractory used. Sometimes you can just clean it up and reface it.

Here's a link for a weight calculator. www.indmetals.com/tools_mtl_wt_calc.asp

if you are planning such a big pour ,a tilt furnace is what you need. however..... for a large pour you will need at least 4 semi skilled helpers to assist! and a crane as well! molding is more important than melting! i think starting from scratch it will take at least 100 or two hundred molding and pouring jobs (these dont have to be big things but do have to be different shapes and sizes.)before you would be able to think of such a large pour...after all at that size a miscast would be disaster!imagine having to cut it up by hand with a hacksaw just to remelt it!for your project i would suggest a steel bed and cast the smaller parts as dave gingery does in some of his books... "build your own metal working shop from scrap" perhaps shelve your drum for now and pick up something like a large propane cylinder. check out aonemarines "elcheapo furnace" you wont get much better than that "elcheapo"

When you say a "tilt" furnace are you reffering to a type of reverber type or something like a cupola that then dumps into a ladle that tips or yes to both. I have a 10 gallon oil drum that is about the size of a 100lb propane cylinder but half as tall. That should get me closer to what we are doing as far as casting in the beginning. I have a list of stuff that I would like to cast. Stuff like blower fans, cope and drag boxes. plaques, paperweights, pictureframes and whatever my kids can carve out of the pink foam sheets that I found lying around at work. By the way can you use super glue to bond more than one piece of pink foam together when doing lost foam and still have it vaporize like it should without leaving a scum layer or scabs?

Regular old hot melt glue works fine. And the lava rocks don't work well, believe it or not they won't stand up to the heat. It's what they make perlite from (a lava-like rock, in any case). What you need is one of a few things, either a clay-foam bead mix, insulating castable commercial refractory, or kaowool (which is supposedly the best stuff to use, if a bit pricey). You can make regular dense castable refractory insulating by adding as much shredded foam or foam beads as it can take and still support itself. The foam burns out as the refractory is fired for the first time, creating air spaces that insulate quite well. I have used the clay/foam mix myself with reasonably good results, although I wound up adding quite a bit of grog to the mix to get it to not collapse after firing.

a tilt furnace is basically a furnace which swings in a frame. it has its melting pot inbuilt so by the use of a lever you tip the whole furnace over to pour the metal. they are used mostly for pouring bronze statues..another idea for your furnave might be to make one like model l www.foundry101.com/search.htm