Tonight I rushed home to attempt melting bronze for the first time. I arrived home, placed my crucible in the kiln and placed a piece of bronze that I estimated was about the volume of my ingot mold into the kiln. I then turned my kiln's two elements on high and closed everything up. Heat recording chart: 4:53 @ ~0030c 6:18 @ 0741c - performed a visual check before melting temperatures 7:06 @ 0918c 8:23 @ 1079c 9:01 @ 1109c - get all equipment ready for pour 9:16 @ 1117c - pour Note I have only opened the kiln once at a hotter temp 1163c according to my notes. I opened it with my fully gloved arm (past the elbo). No noticeable fumes but there was some smoke. The Bronze was flowing and molten. The Bronze was peach with a pearl/opal look to it. There was still at least an ounce visible of borax floating around the edges. Note: I need to clean this out much better. My tongs had a poor grip. I should take 1 turn out of the adjuster, I suspect the coating is burning off the crucible and it is a little smaller. Check fit in AM when everything is room temp. My shank will need adjusted too. My actual pour speed was way to fast. I need to slow down. I underestimated the volume, and over-filled the ingot mold. The ingot is generally poor. Borax worm holes inner mixed with the metal lots of impurities on the edges, but there does seem to be a good core of bronze. If I don't keep this one for posterity as a lesson, I may grind off the impurities and use in a piece. I will need to research how to clean and flux bronze better. Overall, I need to work on my work space I have things that could catch fire in the event of an accident way to close, and I need a rope put up to keep my "spectators" farther away.
Where did you get your bronze or did you home brew this stuff? Seriously, borax is not necessary if you have good quality stuff.
I got it from a scrap yard in Columbus. It is pretty ugly, but tested. I had done a 900c burn in of the crucible (manufacture recommended it) with borax and a lot stuck to the inside like an uneven glaze. Today's test got rid of it.
I saw a picture of your $1K of bronze you got on this forum. Is there a list on the forum for places to buy good pre-made ingots of bronze?
Ah... you got hosed by the crucible manufacturer... SOB. sorry about that. Try to work through it or contact them and raise a stink. Sure, budget casting sells ingots for a decent price with free shipping AND NO SALES TAX! http://www.budgetcastingsupply.com/category-s/1855.htm These are CMX ingots. good stuff. I should have done this instead of giving the state of california 8o some bucks in taxes... BEWARE. The big ones are BIG and won't fit in smaller crucibels... think less than #8. You'll have to cut them down and it's a big hunk of metal.
Assuming Jasons's ingots are as similar to mine as they look in the pic that was mentioned, I found out last weekend that a whole one will fit nicely in a #12 crucible, which holds about 1-3/4 of them when filled about as much as I'd ever really want to fill it. But I would have preferred to have cut up two ingots ahead of time rather than just one, so as not to have to open the lid of the furnace to lower that whole big brick into a raging hot furnace with my pliers-tongs once I had a quarter-ingot sized molten heel to set it down in (It was so close to fitting through the exhaust vent, so darn close)... Let's just say I now have a better understanding of why Jason wears a whole aluminized high temp space suit when casting, rather than just the gloves and a leather apron like mine! Jeff
My fancy zoot suit cost me 2 beautiful back straps off a white tail. No loss, I would have just turned them into deer jerky. (which I'm told would be a crime) lol They are some fat ass ingots I agree. The cheap plier lifting tool is a life saver! THANK YOU!
If you're only going to do an occasional bronze melt, you might get by with your Kiln but I think you'd be ahead of the game building a fuel fired foundry furnace and save your kiln for burn out and baking. If you're just melting aluminum you could get on quite some time with the kiln, though takes a while to come to heat for first melt and opening them hot can be hard on them.....but it is on everything. Best, Kelly
I wasn't going to mention that... 4hrs 20mins for a melt is pretty damn long. I run shells to 1700 in about 40mins and think that's too long. Giant toasters scare the hell outta me. Putting metal tools inside to retrieve a crucible would give me nightmares. Kurtis is in ohio and should be able to get refractory cement easily. Hope he builds a conventional furnace and saves that kiln for other stuff like working shell etc.
