Silver solder.

I recently bought a very used old brass S.P. tender on eBay from a chap in Australia. Turns out that he'd neglected to mention that both the trucks had been broken at some point and then soldered back together by someone with more ambition than soldering skill. Either both had rebroken at the badly soldered joints during shipment, or they went into the box that way...........no way to tell which.

So anyway, I break out the resistance soldering rig and put everything back together, only to discover that my normal "Tix" solder -that works great for replacing those loose bits that are constantly coming adrift from Korean brass locomotives- isn't strong enough to withstand the stress of bending the trucks back into precise alignment, and lets go all over again.

After trying this twice each on each truck with the same result each time -I'm apparently a slow learner- I dug through my soldering drawer and came upon a tube of Kester "Lead-Free flux cored silver solder" (98% tin, 2% silver) and gave it a try.

Results?

The good news is that both trucks are now correctly aligned and *much* stronger than they had been with either the original Japanese solder or my normal "Tix" stuff.

The bad news is that silver solder melts at a much higher temperature than lead-based solders, so using it on a loco boiler -or anywhere else that has a plethora of other solder joints that were made at lower temperatures- would be asking for the other joints to come loose before the silver solder even melted. But on the other hand it works just *dandy* in situations where you need strength and don't have to worry about melting previously soldered joints.

"So what kept the solder joints on the opposite sides of the trucks from melting while you were silver-soldering" you ask?

I just clipped several small alligator clips onto the truck's cross-member to act as heat-sinks, and proceeded as normal with no problems.

Pete

Reply to
P. Roehling
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Hey, yet another use for old roach clips! Should we send the tip to Heloise, or maybe This Old House?

Reply to
Steve Caple

"Steve Caple" wrote

Do people still use alligator clips for that?

Come to think of it, that's a silly question.

Reply to
P. Roehling

"P. Roehling" wrote in news:13jarguru9if820 @corp.supernews.com:

They make fancy "insulated" alligator clips for using as heat sinks. ;-)

I'm a big fan of a pair of pliers, but that's not always practical. (Ever gotten one of them HOT? It takes a while to cool them back down, even if quenched in water.)

Puckdropper

Reply to
Puckdropper

Silver solder has always been stronger than 60-40 tin lead solder. An old trick for putting together a complex assembly was to do the first joints with silver solder and the later joints with the lower temp tin lead solder to avoid melting the previously made joints. At this time I'm note entirely sure just what is out there for "silver solder". The safety guru's declared that tin lead solder was a sefety hazard for plumbing, so all you can get now in NH is a fancy "lead free" solder that has some (maybe a lot) of silver in it. I'd want to do some research to see if the "lead free" solder is same-same as silver solder.

David Starr

Reply to
David Starr

"Puckdropper" wrote

Reminds me of the time my uncle was hanging around in the blacksmith's shop waiting for the farrier to shoe his wife's horse. Being bored, he picked up a brand-new horse-shoe that had just come out of the forge but was no longer quite glowing red hot.

Naturally he dropped it even faster than he'd picked it up, and the farrier looked over at him and said, "Burn yourself?"

With his hand deep in the water-filled quenching barrel, my uncle replied "Nope. Just don't take me long to look at a horse-shoe".

Reply to
P. Roehling

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