[Amps] current threads about silver solder and resoldering

[Gene May]

Some discussants in this have mentioned buying old solder at hamfests, etc.  I do the same, but it is important to read labels carefully.  The solder that has the lowest melting point is (by weight) 63% tin (Sn), 37% lead (Pb).  This ratio also has the same temperatures for "starts to melt" and "completely melted"; i.e., no temperature range with "pasty" solder.  Note well the greater amount of tin, not lead, because tin melts at a lower temperature than lead.  Note also that tin is more expensive than lead.
 
60Sn/40Pb melts very close to 63Sn/37Pb, and has only a small pasty range.  Unfortunately, I have occasionally seen "60/40" solder for sale that, upon reading the SMALLER print, is 60Pb/40Sn.  This stuff melts at a significantly higher temperature than 60Sn/40Pb and has a large "pasty" temperature range, and IMHO, is a pain to use.
 
Of course, I'm sure that no one is trying to mislead anyone in order to save a few cents.

Gene May
WB8WKU