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How to Solder Pewter


#1
   Oh now for another quesiton...I came accross some sheet
pewter....I know pewter is very soft and it melts very easily, can
this stuff be soldered? I haven't tried and won't until I get the
ok... 

Solders beautifully witn the tin/silver “soft” solders. Perhaps the
best one is Stay-brite, used with the flux made for it, or any liquid
soft soldering flux (this is essentially zinc dissolved in HCL to make
zinc chloride. It’s acid, so treat it as such.) or even with the
milder rosin etc, lead soldering fluxes. These solders are sometimes
even sold in hardware stores, or otherwise, Rio Grande, Gesswein, or
other such jewelry suppliers routinely carry it. Do remember that
pewter is essentially tin, with just a little copper. You work it
like pure tin, and it’s melting point is the same: Much lower than
any silver or copper based alloys, and way too low for silver or gold
solders. Thus the tin/silver solders (which are similar to tin/lead,
but don’t look dull and dark tarnished like the tin/lead solders. You
CAN use tin/lead (like electronics or the old style plumbers solders)
solder on pewter if you like, but the lead free ones look better.

In soldering pewter, remember that it not only melts at a low temp,
but also conducts heat poorly, which means that if you leave the torch
in any single spot for more than a moment, you’ll melt it. Practice
on some scrap to get the feel first. In practicing, intentionally let
a bit melt too, just so you’ve got the feel of THAT too.

One interesting effect is to take silver, copper, or other such
higher melting meltals, place them in contact with or on the pewter,
along with the soft soldering flux, and heat that other metal until
the pewter touching it melts to it. You can “sink” silver or copper
or brass wire into the pewter to interesting effects. With some
practice and torch control, the pewter can even get a somewhat
reticulated surface around that slumped in higher melting metal. Since
the pewter is tin, like a tin based solder, when it melts up to the
brass or silver or whatever, it bonds just fine. You don’t need
additional soft solder, though you CAN use it if you like.

Also, you can also join pewter by welding/fusing without soldering.
It conducts heat quite poorly, so if you leave a slight gap (like
maybe a millimeter or so, in your seam, or angle the edges so the seam
butts up at it’s bottom, but has a v shaped channel at the top, for
you to weld into, you can simply place a row of small chips of pewter
on top of the seam. With the tiniest flame you can manage to coax
your torch into giving you, You fuse them into the seam gap by
quickly “pecking” at the chips then pulling away quickly, then back
again (the idea is to heat the chips, not the sheet, much, and you
pull away to avoid overheating. I little torch works wonderfully for
this, but so do larger torches set to small soft flames. I did this
quite a lot with just a small tip on a prestolite type torch. Even a
Blazer would probably work fine. Try it, and you’ll get the idea.
You’ll end up with a weld bead of successive, joined little lumpy
welds. You then lightly hammer these down a bit, and file flush.
Voila: No visible seam at all. And since pewter doesnt work harden,
but actually softens some as you work it, you end up with a seam that
not only doesn’t show, but has the same working charachteristics as
the original metal. If you’re carful to planish/file the seam to the
original thickness, and not thin it out, you can repeatedly place
these welds over and over into the same areas without problems. This
can be used to form complex shapes too. for example… Bend up a
cone shape, weld the seam. clean it up. Cut a series of wedge shaped
cuts across the cone. Bend the cone to close them, and weld up. If
you can get a stake or something inside the cone to support the inside
while you then planish and smooth, you can form smooth highly complex
curves from the sheet metal this way, all without the work and bother
of “raising” or smithing techniques that might otherwise be needed.
Pewter’s softness also means you don’t need expensive steel forming
hammers or stakes. Homemade hammers made of delrin or nylon, or even
hardwood like maple, are wonderful for forming the stuff, and with
fewer surface marks than steel hammers.

Final surface finishes can range from just a uniformly filed surface,
smoothed a bit with steel wool, on out to a fine polish if you like,
with just about anything in between. But remember that it’s softness
means the less refined surface finishes will hold their appearance
better, as even handling with fingers will damage a fine polish. Thus
the popularity of softer finishes like steel wool. If you want some
antiqueing, dilute nitric acid does a wonderful job. Highlight with
steel wool afterwards.

Hope this helps.

Peter Rowe


Repair Pewter Cup