Gresp15C

I just used up a little coil of hard solder that lasted me 20+ years, and have no idea the brand any more. Can anybody recommend a source of such a thing, maybe an ounce of silver bearing "hard" solder and flux for soldering ferrous metals? This would be for use with a propane torch.

HillRider

A Google search for "silver solder" got a ton of hits and sources. One particular one I recognize and can vouch for is Brownells, the g-u-nnsmithing (forum censors won't let you spell out g-u-n) supply firm. Here is their link to the silver solder pages: https://www.brownells.com/items/silver-solder.aspx

dsbrantjr

TIX solder, the hardest soft solder on earth:
Tix Solder (Pkg. of 20 Three Inch Sticks)
Search Results - Micro-Mark
Great vendor, caters to model makers but lots of generally useful small tools and supplies.

long john

Just about all welding stores carry Harris products. Harris has hard silver solder.

dwmckee

Can silver solder be used on stainless spokes?

Gresp15C

I've used silver solder with stainless. In fact, while in grad school I soldered stainless fittings for high vacuum systems -- my biggest job was a 4 inch diameter joint using an oxygen hydrogen torch. That was fun. These days, as suggested by my post, I only use it for odd jobs.

But, will silver solder produce a joint that's strong enough to repair a broken spoke? I doubt it. I'd also wonder about the effect of the soldering temperature and atmosphere on the strength of the spoke wire.

In my experience, getting a good joint with silver solder takes some practice and an understanding of how the process works. Proud as I am of my skills, I wouldn't attempt a structural repair on a bike without getting some bike specific advice from the experts.

randomgear

I've used Harris 45% CF silver to braze stainless steel bits, but not spokes. I don't see a reason it wouldn't work. Just be aware that the 45% silver looks more "golden" than silver or stainless steel.

RoadGuy

Silver solder has been the most common kind since solder with lead as the primary component has been made illegal for most purposes.

You can get silver solder from any home improvement store as lead has not been allowed for use on plumbing for many years now. Lead solder is also not used for soldering most electronic circuit boards either. So you can get silver solder at most hobby stores, and electronic supply stores as well.

dsaul

The stuff you can get at hardware stores is usually the 5% silver type that is just for soldering pipes, wire, etc. and has no real structural strength. If you want to join steel or stainless parts with any strength, you'll need at least 45% silver. It's not really solder, but brazing rod with silver for a lower melting temp, better flow and the ability to wet out on stainless. It can be found at most bicycle frame building suppliers. Cycle Design is one supplier Silver Brazing Wire « Cycle Design

Gresp15C

Yes, just to clarify, that's what I'm looking for. I have a fair supply of lead free electrical solder, since I run a small electronics business. In addition to lacking structural strength, I'm pretty sure that the tin-silver solder doesn't adhere to ferrous metals very well if at all.

HillRider

Highly doubtful as no solder is anywhere near as strong as the stainless steel base metal and the joint would have so little surface area (assuming a butt joint, not overlapped) that failure is almost assured.

Booger1

On silver solder,the higher the number(more silver) the stronger the braze and the less it will fill gaps.56% silver is about as good as it gets without getting too special....But you will not fill any gaps with it.

You can buy Harris at any welding shop or supply.Get the flux you need for the material your brazing.....Or go old school and mix Borax with water and make your own.

You can find some good deals on silver on the Ebay.

dwmckee

I was asking about spokes because some folks used to wire tie spoles where they cross and solder the joint to make the wheel more rigid. I was not thinking of soldering a butt joint to fix a broken spoke!

Thanks for the answers.

HillRider

OK, good to know. BTW, tying and soldering spoke crossings is an old fashion, ineffective and discredited method that was claimed to make the wheel stronger. It didn't. The only advantage to the technique was that a broken spoke wouldn't be able to flop around and get into the derailleur or fork blades as easily. Maybe worth the trouble if you break a lot of spokes.

Here is Sheldon Brown's reprint of a Jobst Brandt experiment to see if tying and soldering improved wheel rigidity: https://sheldonbrown.com/brandt/tied-soldered.html

dscheidt

Harris sell a 56% silver filler as well. It's pretty silver colored. It costs more, of course, since it's got more silver in it, but it's also easier to work with. If an ounce is going to last the OP 20 years, it's probably worth it.

Gresp15C

Thanks for all of the tips. Like @dscheidt says, my anticipated use is minimal, but I have to keep some around for the odd job, and don't mind paying for good stuff.

The previous roll surely paid for itself many times over.

dwmckee

Thanks. I was mostly asking just out of curiosity. Not having any trouble these days.

arex

+1 for gunsmiths.

fietsbob

Jewelers particularly art Metalwork uses the 'hard-medium-Easy Silver solders a lot , to solder 1 piece together with hard,
then attach it to the rest of the larger piece with something with an Easier.. ie lower melting point..
so 2nd joint wont melt 1st solder making the 1st one come un-soldered

So reading the melting point Data is where you can judge how a particular silver solder can be used in such sequential assemblies .

HillRider

Wow, they let you spell it out!

cradom

Quick question...
Most solder from a hardware or plumbing store is acid core whereas electronic solder is rosin core.
Does it matter which kind to solder cable ends and whatnot?

HillRider

For galvanized cables, either will do. For stainless steel cables, neither will do.

cradom

Thanks.

Curtis Odom 

Stick with Harris products. Stay-Brite solder and Stay-Clean liquid flux with Tie-an-Solder spokes. This is all about cleanliness and enough heat.