Quick soldering wire question

[bmortell]

I got this roll of soldering wire given to me its 1.3 lbs, the only info on it is its old and says lead free also its still shiny. So must it be 95/5 or is there something else it could be?

[RogerDat]

Lead free is most often very high tin with a little bit of something as an alloy. Two ways I would personally use it.

I would just guestimate it as 90% tin and use it as a pot sweetener when I felt a bit more tin was needed. Working from a known weight for an inch or few inches of solder is an easy way to add small measured amounts of tine. A little bit in a 10 or 20 pound pot for a tin boost the exact percentage of that small amount of alloy won't matter much.

Or I would accumulate it with other solder scrap until I had several pounds then I would melt it all into one big batch cast into mini muffin tin as 1/4 inch thick "coins". Have that batch tested and label all the coins with the amount of Sn the testing found. I have bags or bins with coins having "denominations" of 23 to 63 percent tin, with a some in the 30's or 40 percent ranges. These come from garage sale and scrap yard solder collecting.

If a found or scrounged roll has a decent amount and a readable label to provide the real alloy composition then I may well keep it on the roll if there is enough of it. Otherwise it goes in the big batch I eventually make when the scrounging finds accumulate.

Might find some useful information on lead free solders here. Be aware they can have zinc in them, small percentage, and small amount of solder into a big pot makes it probably not of concern but it could be. https://en.wikipedia.org/wiki/Solder#Lead-free_solder

oops forgot the link the first time!

[marek313]

I salvaged many punds of mystery solder and unless its on a roll with a label you just dont know. Considering the amount is not even worth testing. I got a lot of 50/50 and 60/40 older solder (in 10lb+ balls) but I also got many user spools of lead free as well. Those are usually around 95% tin. Just add some to your pot when you want more tin and harder bullets and use it up for rifle or magnums.

[NyFirefighter357]

Lead free solder can also have copper, silver, bismuth, indium, zinc, antimony, Selenium, nickel, germanium and other metals. It will be mostly tin 90%+. The two most common lead free plumbing solders are 95/5 & Sterling Lead Free Solder. Sterling Solder is lead-free as well as antimony-free. Tin(Sn) Balance, Copper(Cu)4%-5%, Selenium (Se).04%-.20%

[RogerDat]

I salvaged many punds of mystery solder and unless its on a roll with a label you just dont know. Considering the amount is not even worth testing. I got a lot of 50/50 and 60/40 older solder (in 10lb+ balls) but I also got many user spools of lead free as well. Those are usually around 95% tin. Just add some to your pot when you want more tin and harder bullets and use it up for rifle or magnums.

I love it when someone cleans out the "garage" and brings a big ball of solder wire to the scrap yard. It could be as low as 10% tin or as high as 95% tin but 25-30 is common and getting it for scrap lead price is always a win.

Much of my finds is from garage sales and flea markets. People will sometimes have a crummy old tool box for a couple of bucks with a couple of rolls of solder in it. Fifty cents or a dollar will often bring that roll home with me.

[PBaholic]

Probably a high Tin (Sn) Content alloy. I would mix it with some pure lead, and see where the Brinell Hardness (BHN) ends up. There is likely Copper and other things mixed in with it, which isn't a bad thing. The Cu will just increase the hardness.

Tin in itself isn't the best hardening agent to use for boolits. It'll get the job done, but Tin is going for $7/lb, where lead is only $1/lb.

Here is a good chart on what mixture of Tin and Lead will give you a specific hardness:



Realize that this chart is based on pure Lead and Tin, and you are most likely dealing with less than pure metal.

[RogerDat]

And often not dealing with a binary alloy of just lead and tin. Even a small amount of antimony will add more hardness than a greater amount of tin. Some lead free solder has a some antimony in it.