What are pewterwares soldered with?

[lwknight]

Most of the things are obviously cast in separate parts then soldered together with something.
Could it be a low temp solder like with bismuth in it?

[runfiverun]

could be, bismuth alloys will melt as low as 140*.
but with all that tin around i would think thats more likely whats used.

[fryboy]

some percentage of bismuth could be in the pewter as well .... i always figured it was tin/lead on tin on the parts that didnt matter and tin/bismuth where it did ( ie; food implements ) i've seen a couple of seams that were darker leading me to believe it was lead tin but most the time they are hard to tell

[sagacious]

Common pewter is soldered with ordinary Sn/Pb solders, such as 60/40 rosin core. I have seen the "dark seams" on some soldered pewter, and that's almost surely Sn/Pb solder. More expensive pewter is soldered with Sn/Ag solder, which stays very bright.

[lwknight]

Would a little silver in the solder make the melting point low enough to solder the mostly tin pewter without melting the pewter? I always thought that ant silver would be harder to melt.

[sagacious]

Would a little silver in the solder make the melting point low enough to solder the mostly tin pewter without melting the pewter? I always thought that ant silver would be harder to melt.
Yes, sure seems like it would raise the melting point. But any alloy addition less than or equal to the % at the eutectic point will reduce the melting point below that of the base metal.

For example, Sn96/Ag4 solder melts at 430*F. The addition of 4% Ag drops the 'melting point' of the alloy by 20*F, since tin melts at about 450*F. If your pewter melts at 450*F, Sn96/Ag4 will solder it.

Silver melts at about 1763*F. Adding .5% copper (melts at 1984*F) to the Sn96/Ag4 alloy will actually lower the melting point a few degrees more. That the addition of silver or copper can decrease the melting point of tin seems crazy, but this is a thermodynamic property of intermetallic bonds and alloys.

[MtGun44]

63-37 solder is the lowest melting point possible with tin-lead alloys. Most likely that
is what was used.