On Saturday night I was at Christmas party with some of the glass blower friends and found out an iron pour would be held the next day the crafts center. One of them was running it and some of the others had prepared molds for the pour so I decided to drop by and watch. I'd been to one pour at San Diego State University a few years ago and it’s pretty interesting to watch the process- fire, heat, white hot molten metal and beer (for the spectators). Since I’d left to Singapore they’d started up the equipment for iron casting at the studio here and have been holding a few per year following a mold making class. So all the prep work for the molds is done in advance then when the day comes they’re filled with molten iron leaving you with a chunk of iron in the shape of your design that will last literally almost forever.
A fire is started in a special furnace using coke as fuel which is continuously stoked by an air blower. Eventually the temperature gets high enough to add in scrap iron which will melt and flow down to the bottom of the furnace. At this point a port is broken out from the side and the iron flows out into crucible at about 3200 degree F – at that temp the color is literally white hot and it flows out just like water. The crucible is carried over to the prepared molds and poured. After the iron had cooled and solidified the molds are broken apart revealing the cast pieces- not having seen and of the mold making it was fun to see what came out of all the molds at the end of the day.
It’s really amazing to think people were doing this over a thousand years ago and basically the only difference is they didn’t have an electric air blower to stoke the fire. The air stream was supplied by hand pumped bellows! In this world with everything moving towards higher technology and virtual representations of reality it’s remarkably stimulating to participate is this kind of low tech activity and to actually make something real with your own hands.
after the metal cools the molds are broken apart to release the form
