For what it's worth, I found a source of Cerrosafe (or it's equivalent) that is cheaper than Midway and Brownells. I think Midway wants $20 for 1/2 lb and Brownells is even more. The place I ordered from is $11 and change for 1 lb.

They list it in 2 places on their site with a little price difference (which is a typo).

http://www.rotometals.com/Low-Melting-Alloys-s/21.htm

http://www.rotometals.com/product-p/chambe...loy_1_pound.htm

The second page lists the expansion/contraction specs which looks identical to Cerrosafe and the element content ratios are the same.

Here's the Cerrosafe MSDS for reference - Click to view attachment

Just thought I'd pass it along.