I've just come back from a week's frolics up at the excellent Bullpen Arts Center, working on a series of pieces which have been cast in iron. As I type, three of them are sat alongside me awaiting wire brushing, fettling, chasing and tidying up. Another piece, weighing a good 100lbs, is sat outside as I'll trash the floorboards if I try and bring it in on my own!
Although I didn't really try much new in the way of technique, I learned quite a lot this week. The first conclusion to draw is about the limitations of sodium silicate as a mold binder: large mold elements which get handled regularly are extremely soft by comparison with the equivalent made up from Alpha Set. In fact, some of the mold elements which people were working on would have been simply impossible using sodium silicate. All of the other artists on the course said that they'd had bad experiences using sodium silicate at one time or another, so I'm wondering about investing in a tub or two of Alpha Set. Another clincher for me was the way in which Wez and co. mix theirs up: Unlike the laborious and drill-knackering technique used up at Coalbrookdale of running a drill/plasterer's paddle in the mouth of a bladeless cement mixer, The Bullpen crew simply add a few irregular lumps of iron to the sand and chemicals - these bits flopping around seem to mix everything in wonderfully well. The other top-top picked up from a chap called Casey was to add the catalyst BEFORE the resin. This (despite the John Winters instructions) seemed to result in a much stronger and more even mix which set fantastically solid.
I'd really recommend the Bullpen to any potentially interested parties, be you an artist or a backyard caster - Wez and Helen are lovely people with a fantastic set-up.
More thoughts and tales of what went on - but in the meantime, here are some pictures, expertly snapped by the hand of Mr John Hardy: