I have a question regarding the use of pumice blocks for soldering.
I live in a small coastal town in Venezuela and often cannot easily
get the bench supplies and materials that I need. For example,
Charcoal soldering blocks. they don’t use them here, or at least I
have been unable to find them. I normally use a white soldering
board, however my current project, a filigreed Paua shell brooch
needs something I can press into (like charcoal). I have found a
pretty porous block of Pumice down at the local Chinese emporium. It
looks as though it will do but I would like to know if the pumice or
embedded mica chips will affect the integrity of the welds or
anything else. I would appreciate any comments or feedback on using
pumice in this way.
It looks as though it will do but I would like to know if the
pumice or embedded mica chips will affect the integrity of the welds
or anything else
One of the old techniques is to take several pieces of pumice,
arrange them close together of flat surface and pour on top slurry
made of plaster of paris and powdered refractory brick. ( Nowadays
casting investment is a good substitute ) When set, turn it around
and you have a very durable, long lasting soldering surface. We have
several hundred years of practice to prove that it is perfectly safe
to use pumice for soldering.
Charcoal soldering blocks. they don't use them here, or at least I
have been unable to find them.
Many years ago, a friend in a remote location used many substitutes
in his silversmithing. For charcoal, he obtained charcoal filters
used in aquariums. Perhaps these (or other charcoal filters) are
still available.
Or just a piece of deply charred wood. Hardwood for preference.
Or you can make your own charcoal blocks by heating wood in an
enclosed container. The home-made kind probably won’t be charcoal all
the way through, but it will provide a surface to work on.
(I don’t know what kind of wood commercial charcoal blocks are made
of, but I have my doubts.)