what do i have

[kbstenberg]

I have read before about floor sweepings from a radiator shop. But what would the lead alloy be considered as solder? I smelted some tonight an am wondering what i have. Boy was there a lot of crud with the lead.
I don't have a hardness tester.

[MtGun44]

Should be eutectic solder, 67 % tin and 37% lead, once you get the crud out. A lower
probability is 50-50 solder, but it has a higher melting point and is not as popular. Either is
a great source of tin. If you have a pot full of metal, say 20 lbs and think it is short on tin
because you aren't getting good fill out. If you assume zero tin is in the mix (unlikely, but
a worst case) and want 2% tin ( a good level to get good fill out) you would add 6.4 oz of
tin. Since your solder is either half tin or 63% tin, you would add either 12.8 oz or 10.2 oz
of solder to the mix. This is a tad off since it does not account for the extra 6.4 to 3.8 oz
of lead that you are adding. SInce you probably have at least 1% tin in actuality, I'd start with
around 5-6 oz of your solder to a 20 lb potfull and see how it casts.

Bill

[randyrat]

Very nice stuff....Just put it all in a smelting pot and melt away , watch all the crud float to the top, skim it and put it to some kind of ingots( small ingots).
Now you have some nice Tin to use in your alloys. As MtGun44 said Most is between 50/50 and 63/37.
Don't worrie about crud it will all float.

[kbstenberg]

Thank you. That is what i thought but i wanted to confirm it .
sincerely Kevin

[high standard 40]

I don't know that you can assume anything about the solder except it is a good source of Tin. It is what I use. I was lucky enough to build a good relationship with a local radiator shop near my home and scored about 125 lbs of ingots from solder drippings. You can only guess at it's composition, it could really be anything. The shop I get mine from uses 40/60 solder. The drippings I get from him would include this and whatever was used beforehand in the radiators he repairs. Really could be anything.....40/60....50/50.....60/40.....63/37......or whatever. For my purposes to keep it simple since we really are guessing here, I call it 50/50 and don't look back.
It doesn't matter much if you are only adding enough for good fillout. What I did after smelting all mine into ingots, I used and old 50 cal maxi-ball mold and cast a bunch of solder slugs. They weigh out at 300gr. I add one to each pound of wheel weight metal I add to my furnace and it gives me roughly the 2% I was aiming for. I'm grateful to have it.

[runfiverun]

i'm in the 40-60 camp... i got some from the salvage yard as scrap lead for .40 a lb and just call it 50-50 and throw a one lb ingot in with 60 lbs of ww's.
i save the known tin alloy for stuff that matters.