Butt welding ends of 1/16" stainless wire

The tab on my son's jacket zipper, that you would grab to move the zipper up and down, broke.

I made a replacement as an oblong ring made of 1/16" 316 stainless TIG wire. By the way, this can be done super nicely and easily using round nose pliers -- the result is great looking and is easy to make.

Anyway, in the end I had to weld the link shut, as a butt weld. I used the same wire as filler.

It worked, but left a little "bulb" near the weld. After careful grinding, it is fine, but I wonder: Is there some secret technique to such welding, that would make the weld look very similar to surrounding wire? (TIG)

i
Reply to
Ignoramus25384
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Though it's difficult with TIG, stretching the joint as it solidifies can remove most of the bulge.

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bought a tapered pry bar, annealed it, turned the taper longer and rehardened it. For cruder work I use cheap tapered pin punches as anvils to forge small rings and flares. Stainless forges pretty well cold without cracking, though it can dent the anvil.

jsw

Reply to
Jim Wilkins

Silver brazing.

Dan

Reply to
dcaster

With TIG, a sharp point, good machine, and light touch.

Or you could try spot welding.

Or you could angle the ends at 45 degrees and leave that end in the zipper slider and the finer wire end at the bottom. The angled end would tend to stay in the slider.

_______ / | Weld this end \_______|

-- Some people are like Slinkies ... not really good for anything, but you can't help smiling when you see one tumble down the stairs.

Reply to
Larry Jaques

=A0 =A0 =A0 Dan

That's what I used to do.

Reply to
kfvorwerk

That's what I used to do.

Reply: I still get a small blob on the junction.

Reply to
Califbill

That's what needle files are for.

jsw

Reply to
Jim Wilkins

Too much filler.

Get some .005" flat silver solder from Brownell's, the stuff they use to stick front sights on shotguns among other things. Make your ring with about an .005" gap. Cut a piece of silver solder to fit in the gap. Flux the gap, wipe flux off of metal not in the gap, stick the little precut bit of silversolder in there, pinch the ring gently and heat gently until the alloy melts. Capillary action will keep the molten alloy in the gap.

With TIG, I wouldn't use any filler at all. I'd make the joint with flat faces and no gap, do an autogenous weld.

Silver brazing is quicker, easier and just as strong.

Reply to
Don Foreman

glegroups.com...

=A0 =A0 =A0 Dan

I used borax flux, a tiny piece of silver soldier and used a Prestolite torch. Karl

Reply to
kfvorwerk

It does not work, I tried it. The ends pull away from each other as soon as metal starts to melt.

Here I am not sure how to keep the flame from melting the wire quickly. But it seems worth trying.

i
Reply to
Ignoramus21107

You do not need that hot a flame. A cheap propane torch will work well on relatively small items. You could let your son silver braze his own zipper pull.

Dan

Reply to
dcaster

Is silver soldering really considered "brazing?" Many years ago, I brass- brazed a piece of linkage in my part, but used OA because one of my coaches at the time said, "you have to actually puddle the iron." On my first try, I thought brazing was like soldering and it pulled apart with my bare hands.

But I _have_ silver soldered with propane-air.

Thanks! Rich

Reply to
Rich Grise

Below some temperature everything is considered soft soldered or just soldered. This includes some solders that have no lead and some silver.

But above this temperature is various sorts of brazing. Everyone used to just call the stuff with 35% or more of silver, silver solder, but now with the low temerature solders that contain some solder it is better to use the term silver braze so no one is confused.

Some of the low temperature solders are good for about 10,000 psi strength. The high temperature silver braze is good for about ten times as much strength. However this is for a lap joint with about 2 or 3 thousandth clearance between the pieces.

Your coach that said you have to actually puddle the iron was wrong. Brazing is joining pieces with an alloy that melts below the melting point of the pieces being joined. The pieces being joined do not melt.

This website has much more information.

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Dan

Reply to
dcaster

You could braze using the TIG torch at lower power. Also, you could find a friendly jeweler and ask him to show you how to do this. I'm sure you, of all people, could work out an equitable trade.

Reply to
rangerssuck

Well, the part was a piece of the clutch linkage from my '72 Ford E-100; it was bent into an "L" at each end, and one of the elbows had started to open up. It was like 3/8 steel rod that looked like the ends were forged. I wanted to stick it back together; somebody suggested "brazing", with the OA torch and brass filler rod. The first time I tried, I treated the brass like solder; adhered it to the two sides of the crack, and it opened up almost under hand pressure. That's when the guy said, "puddle the iron," which worked for the rest of the life of the tall car.

So what did I do?

Thanks, Rich

Reply to
Rich Grise

Way too much current. You need to be using a 1mm sharp tungsten at very low current. You want to be running a micropuddle, not melt the whole end of the wire at once.

Small flame some distance from work. The work shouldn't get hotter than very dull red.

Reply to
Don Foreman

Yes. The proper term is "silver brazing". Soldering and brazing are very similar processes, the difference being merely one of temperature. Soldering is typically below 450F, brazing is typically above 800F. Most silver-brazing alloys go between 1100F and 1300F.

So what material does one use to do silver brazing? Why, silver solder, of course!

He was wrong. Soldering and brazing work by raising the work and alloy above the alloy's melting point, which is lower (sometimes markedly lower) than the melting point of either piece being joined. The liquid alloy then forms a solution with the base metal much as water dissolves sugar. When the solution in the joint freezes, you have a joint. The only difference between soldering and brazing is the temperature, and therefore the alloys used. The worst thing you can do while brazing or soldering is to overheat the joint because that can boil some of the constituents out of the brazing/soldering alloy. Welding, by contrast, actually melts the base metals and the parts are joined when the resulting conjoined puddle freezes.

A good silver-brazed joint can have strength of 100K psi. I routinely make special-purpose lathe bits by silver-brazing broken bits of HSS to larger shanks of mild steel.

Yes, propane-air is quite sufficient for small jobs. Some jewellers uses propane-air or oxy/propane. O/A is easier to direct, control and localize, but propane-air can certainly get it done.

There is an excellent reference book about brazing at

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There's a lot of good information about brazing in that book.

Reply to
Don Foreman

Sounded interesting. Don, but why do they need my phone number?

Reply to
CaveLamb

The first time, you probably melted the brazing alloy onto the steel like candlewax. It coated but didn't bond. You need to raise the workpiece temperature to the melting point of the alloy for it to fuse.

When you "puddled the iron" you effectively welded the part after boiling all of the zinc or tin out of whatever brazing alloy you'd applied. You'd have been better off to skip the alloy and use coathanger as a filler rod, actually not a bad approach in a situation like that. TIG rod works very well for gas welding of steel but a lot of automotive parts have been mended with a torch and a bit of coathanger.

Reply to
Don Foreman

Another description that can be useful for soft solders which contain silver, is silver-bearing soft solder. Soft solders (with or without silver content) easily melt without a flame, with a soldering iron or soldering gun.. in the range of about 430-650 F temperatures.

Silver-bearing solders are now becoming popular for use in copper plumbing connections (with propane or MAPP gas torches. The newer lead-free plumbing solders are generally silver-bearing (soft) solders with maybe 6% silver content.

Actual silver solders are high temperature application, and hard compared to low temp soft solders. Hard silver solders aren't going to melt/flow with soldering iron temperatures, and are typically stiff like steel wire.

Soft wire solders, even silver-bearing alloys, can easily be wrapped around a finger without discomfort.. trying the same test with hard silver solder will be painful unless the silver solder is very thin.

Hard silver solders are applied by brazing, technically speaking. Applications involving soft solders are soldering, whether or not the heating source is a soldering iron or torch.

As Dan pointed out, neither of these processes will require melting/puddling of the base metals. Both soldering and brazing products (wire, rods) will fail at those temperatures.

One example of metal joining/repair that may improperly be referred to as soldering or brazing, would be those "miracle" aluminum repair rods. These actually require welding, since the rod material is required to mix with the base metal when joining aluminum parts. The welding temperature is fairly low, about 750+ F, simply because aluminum alloys have low melting points. This process wouldn't technically be defined as brazing or soldering, because the filler material/rod is actually mixing with the aluminum alloy base metal.

This aluminum repair rod example gets a little cloudy, because the aluminum repair rods can also be used with other non-ferrous metals.. brass, copper, for example. When these other metals are joined with aluminum repair rods, the process is more closely related to brazing.. but could be considered soldering.

Reply to
Wild_Bill

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