Alumina soldering block

Quick question here…do any of you use the soft alumina soldering
blocks sold everywhere. Not to be confused with firebricks. If so,
how do you find them to work? Do they last long, are they a
troublesome heatsink, etc. Any feedback would be great. Thanks. Danny

Danny, We use the alumina blocks at our school and they work
reasonably well. The students tend to tear them up rather quickly
but guess that’s to be expected. They like them because they are
soft and easy to anchor items into. They are not a heat sink…they
reflect quite well. I would say they are a nice addition to a shop.
I have one in my personal shop as well but only use it now and then.
I have an old refractory brick I got in Taiwan about 30 years ago and
it is still going!! Besides that, I ‘air solder’ most of my items if

Cheers from Don at The Charles Belle Studio in SOFL where simple
elegance IS fine jewelry! @coralnut1

do any of you use the soft alumina soldering blocks 

Hi Danny, Yes, I use them. As with a charcoal block they’re best when
they are in new, pristine condition. Unlike a charcoal block, they
don’t help create a reducing environment, reflect rather than absorb
heat, and they don’t burn.

When I find the alumina blocks to be indispensable is when I need to
pin work down to prevent shifting during soldering. I take some
straight steel pins, cut off the heads, and form a hook on the end
with pliers. I can then insert the pin all the way into the block and
hold wires in place securely. Much easier to pin than a charcoal

This works best, as I mentioned, when the block is new. After some
use, the heat seems to fuse some of the surface, giving it a harder,
somewhat glassy texture. The well used surface becomes crackled and
develops a bit of a depression where material has fused together.

They do last a long time, and don’t tend to crumble like charcoal.
Their suitability for a variety of purposes diminishes with use, as
the surface deteriorates.

All the best,
Dave Sebaste
Sebaste Studio and
Carolina Artisans’ Gallery
Charlotte, NC (USA)