Soldering stainless steel wire

On Tue, 18 Feb 2014 06:20:06 -0800 (PST), " snipped-for-privacy@krl.org" Gave us:

They use Nickel clad Copper, generally.

The solid nickel stuff went out as crimp terminations got better. Now, soft braided large gauge DC feed lines are not uncommon.

Some argue crimp AND solder fill in *some* applications. A lot to consider, however, when adding solder to a crimp term, and especially a larger sized one.

Anyway... these days, they'd just use Silver itself. There is enough of it. Just like the little links and coils in RF assemblies.

On Wed, 19 Feb 2014 12:44:49 +1100, Sylvia Else Gave us:

If you do attempt to plate it first, be sure to abrade it roughly first. Like with a file even... BIG scratches.

Plating (electroplating) tends to follow underlying contours until it starts getting 'thick'. You can use the scratches as a gauge for the plating thickness.

CRC handbook has a guide on certain metallic platings and the thickness at which they no longer reflect the underlying 'texture' features.

Stainless wire is drawn with a very clean surface quality, for typical medical application, so abrading it should make it plate better, and take whatever you are trying to make solderable with it affix better.

On Wed, 19 Feb 2014 13:38:34 +1100, F Murtz Gave us:

You use incorrect terminology.

Can attach, but the action is not "soldering".

Soldering leads to a battery is really a bad idea. The battery life will be short at best.

tm

Maybe an after-market fob would have better battery contacts, but how to know? All three of the manufacturer supplied keys that I possess have displayed the same problem.

Sylvia.

Jaycar used to sell them, but stopped doing so. I haven't looked for them since. Using them in this application wasn't so easy, since I had to trim the tab, and at least one came off in the process.

Sylvia.

Soldering batteries without tabs is a bad idea. The bump indicating the '+' side is usually a spring loaded pressure relief valve. You'll melt it shut with the soldering iron if it's made of plastic.

Try replacing fob's power filter capacitor with an ultra-low ESR cap, like a 100 microfarad MLCC. The contacts will spot weld themselves to the battery as needed.

I'm talking about silver oxide button cells.

Sylvia.

Soft Soldering

All grades of stainless steel can be soldered with lead-tin soft solder. Leaded solders should not be used when the product being soldered is used for food processing, serving or transport. Soldered joints are relatively weak compared to the strength of the steel, so this method should not be used where the mechanical strength is dependent upon the soldered joint. Strength can be added if the edges are first lock-seamed, spot welded or riveted. In general welding is always preferable to soldering. Recommended Procedure for Soldering

Recommended procedure for soldering:

? 1. The steel surfaces must be clean and free of oxidation.

? 2. A rough surface improves adherence of the solder, so roughening with grinding wheel, file or coarse abrasive paper is recommended.

? 3. Use a phosphoric acid based flux. Hydrochloric acid based fluxes require neutralising after soldering as any remnant traces will be highly corrosive to the steel. Hydrochloric acid based fluxes are not recommended for soldering of stainless steels.

? 4. Flux should be applied with a brush, to only the area being soldered.

? 5. A large, hot iron is recommended. Use the same temperature as for carbon steel, but a longer time will be required because of stainless steel's low thermal conductivity.

? 6. Any type of solder can be used, but at least 50% tin is recommended. Solder with 60-70% tin and 30-40% lead has a better colour match and greater strength.

Here's a photo of SS tube into a brass fitting

George H.

It's easy to soft-solder stainless steel, if one uses the correct flux.

Tinners flux (zinc chloride and hydrochloric acid in water) is available in many hardware stores, and will usually do it.

There are also liquid fluxes (containing phosphoric acid) intended for stainless steel. If you are doing much soldering, I'd get the correct flux.

In both cases, the surfaces should be cleaned mechanically until bright.

Joe Gwinn

Some good info here. I use boraxo for solver soldering and brazing. About s oldering batteries, I went to a battery store and they spot welded it for f ree. Its a chain that just does batteries - you can google it, but don't kn ow where you are.

If i were going to solder to a battery, I WOULD PROCEED AS FOLLOWS:

1. put battery in freezer.
2. Come in with a fairly hot torch like a butane micro-torch, and get some solder flow onto battery surface - Hold inner tip of flame on one spot. imm ediately wipe with steel wool or sponge. Immediately drop into ice water.
3. Then tin wire and solder it to the tinned battery surface with a weller gun or microtorch. Immediately drop back in ice water. Seek to get 10 secon d heat exposure maximum, preferably 5. If you want to try the above, you will need a fixture to hold the battery, that can be immersed in the ice water. Every hand motion has to be planned. For instance, when using a torch, just drop the torch in a tin can to save the .3 seconds it would take to set it down on a table. Will this work? I think it will, but heat control the issue.

best is spot welding, and battery store was life saver for me recently. The y also told me they would give me some leads they use for spot welding - th ink they are nickel. I am in Ann Arbor Mich, and the store had a name like "Batteries plus some other junk. JB

George -

That's beautiful!

Please tell me what you used and the process.

Thanks, John S

INED

Ahh it's just soldering. I used the Harris Stay-brite solder* and Stay-cle an flux that I linked to upstream. Brass piece went on a hot plate, add fl ux, heat with a propane torch (Typical plumbers torch). Add solder.. done. Well clean all the flux off!! Scrub with hot soapy water.. Oh and of course, as with all plumbing type work, get everything really cle an beofre starting. I always do some mechanical cleaning with fine sand pa per or a "green scrubbie" (those scotch brite pads.) As well as some chem ical cleaning to get the grease off of the surfaces.

Oh one warning about the flux... it's fairly corrosive and you do have to m ake sure to remove it all when you are done. It will sometimes splatter wh en you heat it and you have to make sure you clean up all the little splatt er spots.

George H.

lean flux that I linked to upstream. Brass piece went on a hot plate, add flux, heat with a propane torch (Typical plumbers torch). Add solder.. don e. Well clean all the flux off!! Scrub with hot soapy water..

lean beofre starting. I always do some mechanical cleaning with fine sand paper or a "green scrubbie" (those scotch brite pads.) As well as some ch emical cleaning to get the grease off of the surfaces.

make sure to remove it all when you are done. It will sometimes splatter when you heat it and you have to make sure you clean up all the little spla tter spots.

I just wanted to add that if I really want a good leak tight joint I will t in the stainless steel tube first. Tinning involves flux, heat, solder and then a quick wipe of the tube with a paper towel while it's still hot. T hat removes all the excess solder.

Geo

Solder alloys with the surface, to a depth dependent on temperature, and duration. Soldering copper creates a layer of a type of bronze.

I'm in Australia.

For better or worse, I've gone with soldering to the battery. If it dies within less than, say, a year, I'll have to rethink, but for now the job is done.

I did have some success both spot welding and soldering galvanised steel wire, but the thinnest my hardware store had seemed a bit thick for this application (which is space constrained).

A practical concern with some of the proposals here is that I'm soldering to an electronics board that is expensive to replace, so I have to be rather conservative about the approach I use there. I'm not about to apply aggressive fluxes and brazing torches.

Sylvia.

On Wed, 19 Feb 2014 06:22:51 -0800 (PST), George Herold Gave us:

More likely Sil-Fos

Silver brazing.

But I know nothing about metal joinery, eh.

One cannot solder stainless steel; weld copper, silver or brass to it (or electroplate as you mentioned). BTW, if you are working with stainless steel, make sure all pieces are from the same batch and you use some of that for welding the rest.