Yes, you can solder pewter. I friend of mine taught me how to use
pewter for making master models for casting. I use a soft flame -- a
SMALL soft flame -- on my torch. I use flux-free 60/40 solder,
forging or rolling it to a very thin strip. I then cut snippets from
this strip. If I can't get flux-free solder, rosin-core from an
electronic supply will work. Acid core as used by plumbers and sheet
metal workers does not work well. For flux, I use a mixture of
glycerine and hydrochloric acid. The hydrochloric acid can be bought
from hardware stores in the US under the name of muriatic acid, an
old name that we Americans have yet to abandon! Add the acid to a
small amount of glycerine until the mixture turns amber or brown
Fit all seams just as you do for other metals. place small snippets
of solder next to the seam, and flux. GENTLY heat with a small, soft
flame. Remember that pewter alloys, either old pewter or modern
lead-free pewter melt between 450 and 500 degrees fahrenheit,
depending on the alloy. Seams will run by capillary action, just as
with other metals. Pieces can be sweated together. Other components
can be attached to a base piece. All this just like other metals,
but much more delicate in reaction to heat.
One technique that my friend uses, but I have yet to master, is to
FUSE pewter into rough forms for models. He uses pewter instead of
wax to build his model for casting items. He rolls a pewter wire,
and uses the torch flame to build up areas on the model, and later
files them to final shape and finish. He is encouraging me to build
models from pewter because I seem to have a problem visualizing the
surface of a wax model in the same way that I see metal. I don't
seem to be able to get the finish as clean as I do when working with
metal, so I am learning pewter!
You will collapse a few pieces before you learn just how hot you can
get the metal. Pewter doesn't glow when heated. It just gets too
hot, then collapses. I say this to encourage you. After you
collapse a few trial pieces, you will get the hang of it!
Good luck ...