Old refrigeration lines

[Barefootbandit]

Have a question on old lead refrigeration lines, maybe you guys can help me out. Not too long ago a very very old plumber called me up because he had a big basket full of old refrigerant lines. According to the old codger these lines were 50-60% tin because of the way they "crackel" when you bend them. My buddy and fellow caster doesn't believe it. I myself have no idea what these old lead lines were made of but imagine a pure lead line would be too soft for the pressures of a commercial amonia refrigerant system (I assume it was ammonia but didn't ask). Does anybody have any experience in these old lead based coolant lines? They were free to me for helping move a few heavy objects out of the garage for him, so it was a win no matter what, just curious.

[Drm50]

I have never seen a lead refrigeration line. I seem to remember some zinc or galvanized lines,
they must have been steel.

[bumpo628]

I think tin is the only metal that 'cries' when thin sections are bent. So maybe the old timer knows what he's talking about (they often do).
Melt it up, check the melting temp if possible, and check for a gold color to the ingots.
Or you could get it scanned and know for sure. You could also cast a boolit and compare the weight to lead.

[Jeff Michel]

Refrigeration solder is actually silver brazing alloy usually 15% silver alloy, the balance is different metals to act as wetting agents or as flux. Temperatures are right up there, you have to use acetylene to fuse your joints

[William Yanda]

Tin will cry when bent, allegedly it was used for refrigerant lines. Check the melt point. You may have a treasure. Just a little will alloy with a lot of lead at 2%.

[6bg6ga]

Quote: Refrigeration solder is actually silver brazing alloy usually 15% silver alloy, the balance is different metals to act as wetting agents or as flux. Temperatures are right up there, you have to use acetylene to fuse your joints Absolutely correct. believe most are nickle silver. I still have two or three sticks left.

[farmerjim]

45 years ago, I bought old refrigeration lines from the scrap yard that were tin. They worked good in my boolit alloy. I did not have a casting thermometer back then, but it easily melted into my lead.

[6bg6ga]

Funny thing....I have worked on refrigerators and freezers from the 1930's on up and have never seen these tin lines mentioned. I've worked on very old central air units and all had copper lines.

[rancher1913]

I've got some, they are as stiff as soft copper and I thought they were aluminum but the scrap guy said no they were lead refrigerant lines. they melt at the same temp as lead, had my smelter full of soft lead and dipped one end of the line in and it melted right away, dipped some known zinc and it just sat there.

[swheeler]

Old refrigeration lines are listed in several cast bullet manuals as a source of tin, pictures included.

[dragon813gt]

Refrigeration solder is actually silver brazing alloy usually 15% silver alloy, the balance is different metals to act as wetting agents or as flux. Temperatures are right up there, you have to use acetylene to fuse your joints

That is not what this thread is about. He is asking about the actual piping. Not what's used to solder the joints together. I also would not bet on the joints always being brazed w/ a 15% alloy. R22 pressure was low enough to get away w/ using 95/5 solder. While not recommended I know of a lot of companies that did it for many many years.

[runfiverun]

old beer tap lines were a high tin - low lead alloy also.

[Barefootbandit]

Wow you guys are fast. Thanks for the input. They are definitely some form of lead tin alloy. Its the whole pipe, not just the solder. Probably 60+ lbs worth. Is an IR thermometer accurate enough to check melting temps? I'm inclined to believe him, he's been plumbing for close to 60 years and learned from his dad. Maybe it's time to break down and buy a proper thermometer.

[mfraser264]

The "crinkle sound test" is an old standard I learned from a friend who grew up in the scrap business. They bought these lines as "Tin" sold them on the whole sale market as "Tin", nice find, enjoy.

[bangerjim]

Old refer lines were 100% Sn. I hauled home about 60# of the stuff last year at Pb prices!

Nice stuff when you can find it. Used on commercial set-ups - - not home A/C or freons.Very common in the old days, espeically around ammonia refrigeration so I was told by several old ammonia guys.

IR will NOT read the temp of a shiny surface at all. Way off. They do not work for what we do. You need a standard casting thermometer.

The joints are brazed with Silver Solder.......the GOOD stuff. No good to us. I have 40# of the stuff I use for strong brazing with an oxy/propane torch. Stiff thin wire.....not the kind of solder you are used to seeing.

bangerjim

[RogerDat]

Believe it is called "Block Tin" at least when it was used in the old style beer tap cooling lines that ran through ice in a sink. Think it was mentioned in some of the past Lee reloading manuals. Know a guy that has about 10# but he wants $6 a pound and always decides he doesn't want to sell it when one makes him an offer.