But, I haven't been able to locate a supplier. Anyone know where to
If the one you're describing is the one I think it is, look at page
380, item 'C' in 2006-2007 Rio Grande catalog.
They list a 713/16" x 5 1/2" x 1/2" block for $11.50.
Another item that works very well for the job you're describing is a
magnesia firebrick, also called a silversmiths firebrick. These are
soft enough to push pins in any place you want, but hard enough to
stand up to years of service. If your jewelers supply doesn't stock
them, check out a home supply or a brickyard. One brickyard that I
know has them is the Phoenix Brickyard (phxbrickyard.com). They're
not listed on the site, but if you contact them they'll ship them to
Usual disclaimers, just a satisfied customer..