Lead-free solder?

[jorymil]

Are any of the repair techs here using lead-free solder regularly? I tried it out over the weekend to patch a hole in an old tuning slide, and it really is difficult to work with: there's this range where it tends to melt and clump before being hot enough to flow.

I'm all for keeping lead out of the environment and my body, but if it takes multiple attempts to get a good joint, all the while dealing with flux vapors, I'm not sure it's better for an amateur.

[ithinknot]

Not a tech, but have used 96S a bit. It's definitely a bit trickier, with the slightly higher melting point and that pre-flow clumping range you talk about - I think of that as the 'cottage cheese stage'... But once you get past that it's fine. Doesn't heat-and-wipe quite as cleanly as 60/40 or 70/30 either, but again quite manageable.

I'd say for jobs where there's surrounding lacquer to try and save I wouldn't necessarily bother, but it's great for higher strength locations like water key or lever saddles, and on silver or nickel plate for cosmetics - it stays bright rather than going dark over time (or at the next acid bath).

What kind of torch are you using? I can imagine it might not be too fun with butane and an unfocused flame...

[Crazy4Tbone86]

I have done work with low-temp silver solder as well and know a tech who has used it a lot. The hassles are exactly what ithinknot has stated. The bond is very strong and trombones play very lively when this solder is used.

I decided to NOT use it when someone showed me a horn (fully assembled with low-temp silver solder) that sustained some serious trauma. The brass tubing actually tore in a couple of places because the bond of the low temp silver solder joints was stronger than the brass. That sort of freaked me out. It seemed apparent that the softer lead-based solders were ideal because, in an instrument accident, the solder joints would come apart in order to protect the brass components in the instrument.

[jorymil]

I was using the lead-free solder to make a patch for a nickel silver Reynolds Contempora tuning slide. Some poor soul used it for a wall hanger in a previous life; very clear that a drywall screw was involved!

The torch I'm using is a Lexivon butane torch purchased off Amazon. It's not the greatest, but it does have a decently adjustable flame. It will not handle silver soldering, but it does get hot enough to anneal my small nickel silver patches. If I end up doing a lot of work, I'll probably want to get a nice propane torch.

I went back and inspected my work; the joint is quite solid. As with so many things, the reality of it is very different than what you see on YouTube! I'm going to stick with it at least for this job.

ithinknot, thanks for confirming that I'm not crazy about the clumping: I wasn't expecting that at all when I started. I'm definitely not worried about preserving lacquer here: my skills aren't quite there yet. I have a horn where that _will_ be an issue; may just take it to a pro.

Brian, thanks for your experience on the solder being stronger than the brass in some cases. That would be a very bad thing, say for large-surface flanges: I'd really hate to have a hole torn out of a bell or a valve casing, for example. What sort of trauma did your example horn run into?

[boneagain]

What kind of torch are you using? I can imagine it might not be too fun with butane and an unfocused flame...

jorymil,

The higher the heat needed to flow your solder, the more you want a more focused heat source.
You can cook metal by leaving heat on it too long.
You can loosen OTHER joins by heat spreading.
Butane is "lower energy" than propane.
Any chance you can find an affordable propane option?
Ultimately you want to get the "right" amount of heat in the right place for the right time.
Hard to do with a butane torch.

For ME, starting out with butane THEN switching to propane after getting pretty good with the butane would be REALLY discouraging. I'd have to relearn every sense of timing and flame movement, and I'm not good at that kind of neuro-motor coordination. But YMMV.

[Crazy4Tbone86]

Brian, thanks for your experience on the solder being stronger than the brass in some cases. That would be a very bad thing, say for large-surface flanges: I'd really hate to have a hole torn out of a bell or a valve casing, for example. What sort of trauma did your example horn run into?

When I worked in a big shop, the lead technician/educator had dozens of instruments and/or parts of instruments to show what can go wrong with bad repair technique. He had pistons that were lapped too much and became leaky. He also had trombone outer slides that had outward grooves because someone got too aggressive with an outside slide internal burnisher, a tool that some people call the "slide expander tool" (presently discussed on another thread). He had a great collection of brass and woodwind instrument mishaps to show people that they need to be careful with their work.

Every now and then, someone would say....."Maybe we should use that low-temp silver solder on repairs because it is stronger." The lead technician would explain that you cannot mix the two types of solder at the same spot and then he would talk about the problems of moving away from the traditional lead-based solder. He would pull out a trombone bell (fully custom assembled, all with the low temp silver solder) that was smashed in the trunk of a car that got rear-ended while parked on a street. The solder connection on the diamond-shaped bell brace was so strong that it tore some of the bell stem off of the bell. It was a very convincing piece of evidence.

I only use the low temp silver solder to assemble small parts like a broken water key or a rotary linkage part. It is finicky to work with because (as stated earlier in this thread) it goes from clumpy to fast flowing very quickly. When it flows, it doesn't always cling or stay where I want it to stay like the lead-based solders. Thus, I sometimes end up doing a lot of filing and sanding to get a nice looking end product.

[jorymil]

Any chance you can find an affordable propane option?
Ultimately you want to get the "right" amount of heat in the right place for the right time.
Hard to do with a butane torch.

Sounds like saving up for a nicer torch would be worth it. Propane is fortunately quite cheap; it's the torch portion that's expensive. Any recommendations?

[Crazy4Tbone86]

Any chance you can find an affordable propane option?
Ultimately you want to get the "right" amount of heat in the right place for the right time.
Hard to do with a butane torch.

Sounds like saving up for a nicer torch would be worth it. Propane is fortunately quite cheap; it's the torch portion that's expensive. Any recommendations?

A propane torch set-up is extremely cheap. Here is a torch head that will work fine for under $20....

https://www.acehardware.com/departments ... es/2138840

I use a similar torch head all of the time. If you want a lower temperature flame, use Coleman's campfire propane mix. For a slightly hotter flame, use Coleman's standard propane.

[boneagain]

I agree with Brian's reply. Especially the part about "... is extremely cheap."

But keep your total cost of ownership in mind.

The kind of propane torch he links to will, IMHO, be fine for a very large percentage of horn work.

But there's a continuum of capabilities. The keys to capabilities, and costs, are air and gas.

I have soldered probably miles of copper (before the rise of plastic plumbing) with a Bernzomatic. It is pretty self contained. That keeps the cost down. But I ran into MANY torch jobs that the torch could not keep up with.

If you look at Ferree's you'll find a nice selection of torches known to do well for instruments. There are little butane torches in the mix. There are also some "gas air" units. These go for around $100 just for the torch. Then you need the hoses. And regulators. And some source of gas, and some source of air (compressed bottle or compressor.) That can add up quickly.

A more recent development is the Turbotorch, like this:
https://www.amazon.com/Victor-TurboTorc ... 261&sr=8-5
There are SEVERAL models, and different heads. I think of them as Bernzomatic on different types of steroids. Turbotorch fine tunes the induced air mix in the head, trading flame volume for intensity. I was able to test one silver soldering the seam for a hand hammered alto tuning slide. I would have been challenged using that head for soft soldering! OR for annealing! Quite pricey, but no extra tanks, or compressors, or double hoses...

This context makes Brian's recommendation even more attractive.

Guess I'm just beating around the bush of not knowing quite what-all you wish to achieve with your torch. If you are JUST going to apply surface patches then I would go with a Bernzomatic. If you might unsolder, clean, and rebuild sections, I'd probably look at one of the lower heat Turbotorches. If you might do lots of small silver solder, and annealing, I'd get a fairly sizeable compressor and gas-air like at Ferrees.

Does that muddy the water sufficiently?

[boneagain]

Ah... I thought this discussion looked familiar:

Better opinions than mine here:

https://trombonechat.com/viewtopic.php?t=19498

[jorymil]

Sounds like saving up for a nicer torch would be worth it. Propane is fortunately quite cheap; it's the torch portion that's expensive. Any recommendations?

A propane torch set-up is extremely cheap. Here is a torch head that will work fine for under $20....

https://www.acehardware.com/departments ... es/2138840

I use a similar torch head all of the time. If you want a lower temperature flame, use Coleman's campfire propane mix. For a slightly hotter flame, use Coleman's standard propane.

I have that head! If you're happy with it, then no reason to look farther for now.

[jorymil]

Thanks to you both. I'm just an amateur doing this for fun on horns that aren't necessarily worth much money. While I _might_ silver solder one of these days, I need to learn the regular stuff well enough first. That's joining tubes and patching holes

[jorymil]

Patches complete! Friends don't let friends put screws into a Reynolds Contempora

[boneagain]

Did you finish up with propane or butane?

[jorymil]

Did you finish up with propane or butane?

Stuck with the butane for this one. Getting ready to move, so this will be the last time the torch comes out for a month or so.

[boneagain]

As Sam always said, "Try everything... use what works"
Good luck with the move!