Originally Posted by
kevin c
Well, I just tried out the aluminum strips on my 1100 watt coil, with the bread pan mold garage. The garage I went a little crazy on: it's two bread pans nested, sandwiching a layer of pink Fiberglas insulation, with one end cut off for mold insertion.
TOO HOT!!! A few minutes between medium and high (I used to use the maximum setting before) had the mold smoking when I rubbed a two stroke oil soaked swab over the sprue plate, and the first pour of 720° alloy (PID controlled pot) the sprue would not solidify at all; it just ran off the top of the plate and left little puddles in each sprue hole. The blocks and plate were so hot that even after a minute and a half the lead in the sprue channels was liquid, and when I relaxed my grip on the handles I discovered the lead in the cavities was the same as it drained from the cavities out between the mold faces.
Starting with another mold cold, even medium heat settings caused smoking and little frosted BB's. This is going to need more work...