Rosin core/ Acid core solder?

[crabo]

The hardware store is going out of business and there are several 1 pound spools for 60% off. I couldn't find a notation on what the makeup was. Any good for adding tin?

Crabo

[Baron von Trollwhack]

It will work fine, you just have to know what the alloy is for it to be of use. BvT

[mto7464]

probably a Lowes, homedepot, or manards near by right, you can never find help in those places and they put all the small ones out of business.

[JSnover]

If the alloy composition isn't on the label, try contacting the manufacturer or a distributor and give them the part number. You might even be able to search online by part number for an MSDS.
If it's even remotely toxic, somebody has a material safety data sheet for it. I bought some solid carbide tooling last year and the MSDS warned me that toxic fuumes could be created if I raised the temperature of the tool beyond its boiling point; something like 3500F. Holy Crap! Not much to worry about there!

[Typecaster]

I've picked up full and partial spools that were so old that the spool was too rusty to read. It's unscientific, but old 50/50 will oxidize and turn gray; 60/40 (like is used for most stained glass work) doesn't seem to oxidize even when it's old because of the extra tin.

Most of the real old stuff I've found is solid. You can always use a soldering iron to check whether it's rosin core or acid core—if it's rosin, you'll smell it. I even seem to remember that the acid core tasted sort of sweet if you cut the solder wire. It''s amazing that I survived childhood.

When in doubt, I just calculate tin content as 50/50. If it's 60/40 or so, it'll just make the mix a little richer. In 30+ years of collecting, I've found 1 roll of pure tin wire.

[Huntducks]

50/50 number one plumbing solder for years also 80/20 and 95/5 just picking up a roll weight and bending it you new the differnce.

[Harry O]

I just bought a bunch of solder at a garage sale today. Got 3-1/2 lbs for $2.50. Looked and could not find the ratio on them or on the box one of them was in. They were old, though. I have done the same thing in the past and have assumed it to be 50-50 unless otherwise noted. Melted them down (including the rosin core ones) and cast it into 4oz ingots. I assume that it is 2oz tin and go from there. Works well.

I believe that anything more than 50-50 is marked to justify a higher price.