Cable nipple soldering

[Greenfield]

Perhaps an old topic but just looking for some quick tips.
I'm having a problem soldering a brass nipple to the end of a brake cable; which is presumably made of stainless. I just can't get the solder to fuse with the cable, even on the freshly cut ends of the cable strands. With other cables its simply been a matter of remelting the solder but with my current cable, the cable has been shortened so I need to 'wet' fresh cable. It's been thoroughly degreased and polished with emery, but the question is what flux to use without spending an arm or a leg? My searches indicate that it needs to be phosphoric acid based.
Any tips?

[Bess]

Hi,
     Worth trying flux coated silver solder sticks.

Best wishes...

[Spaceman]

Unless you've specially bought it in that form, I would be surprised if the inner cable is stainless. The problem is more likely to be the one you get trying to solder connectors on to older electrical cables - the tarnish, corrosion, oil, grease and dirt can make it very difficult for the solder to get to the metal to wet it. You normally have to go to a great deal of trouble to clean the metal well enough to be able to successfully solder it.

However, if this is a new cable and it is SS then you will need to use the a phosphoric acid flux to be able to solder it - there are plenty on the market. I assume the end of the cable is being formed into a ball before it is soldered to the nipple?

[Greenfield]

Its an old cable, age unknown. Let's say over 10 years, but could be 20 or more as it was on the bike when I got it.. There is no evidence of any rust in it even when untwisted, so guessed it could be stainless. The nipple is yellow metal and I assume is brass rather than a moulded lead one. The hole in the nipple is wider at one end and I've opened/spread the cable to fill the larger hole when soldered. It's the front brake cable so a lot depends on a good solder flow!

[Oily bloke]

I use a generally available acidic plumbers solder paste from Wickes and an electric solder pot. If there is any oil on the inner I clean with copious amounts of brake cleaner.
A light smidgen of flux and dip in the pot. I make sure the pot is not too hot. Just fluid beyond the wax stage. I have made tens if not hundreds of cables this way and have yet to have one fail. I made a simple 'bird cage' tool as the ones available were way too expensive.

[Greenfield]

 Thanks 'Oily bloke'. Just looked on the Wickes website and it shows La-co flux which is non acidic. What's the name on yours and I'll see if I can track some down? Are you using lead free solder or the old stuff with lead. I've been trying with the latter.

[ducati2242]

The birdcage the cable tip and spray it with brake cleaner is the best advice you will get . I use modern lead free solder and the oily flux . Again I made my own birdcage jig .

[Spaceman]

Its an old cable, age unknown. Let's say over 10 years, but could be 20 or more as it was on the bike when I got it.. There is no evidence of any rust in it even when untwisted, so guessed it could be stainless. The nipple is yellow metal and I assume is brass rather than a moulded lead one. The hole in the nipple is wider at one end and I've opened/spread the cable to fill the larger hole when soldered. It's the front brake cable so a lot depends on a good solder flow!

Unless you've got a birdcage jig, I would recommend buying a new cable and modifying that if necessary. The strength of the finished cable will depend on a well formed birdcage and will not be strong enough if you are relying mostly on the strength of the solder. 

[TTJOHN]

Bakers flux, is the answer, apply before soldering.

[idie]

Some cable are stainless almost impossible to solder. The nipples are crimped on.

[Mike Farmer]

 

I must seriously confess that whilst my soldering skills are well up to putting in a central heating system I have never been successful with cables and nipples. Therefore I do not hesitate to buy new or if I need something different I have it made locally by a "trusted source".

Considering the front brake as an instance, you have about a dozen Sq" of shoe trying to stop 3 or 400lbs or so of bike on about 6 sq" of rubber touching the road surface. Reliant on a cable with a nipple that may or may not be well soldered. Not 100% ideal situation.

If, as so many of you more adept guys are able to do, brilliant and long may you be able to. Very personally I'll continue to buy or have mad. Its probably cost me more in materials and exasperation than new anyway.

Take care and enjoy

Mike

[Oily bloke]

Thanks 'Oily bloke'. Just looked on the Wickes website and it shows La-co flux which is non acidic. What's the name on yours and I'll see if I can track some down? Are you using lead free solder or the old stuff with lead. I've been trying with the latter.

I have been using Wickes active plumbing flux but I think it may be obsolete so maybe Bakers No' 3 soldering flux may be the next best. Any good flux that has an active etching/cleaning action. The solder is a mix of what I had from lead shot, body solder and plumbing solder, so lots of lead going on there. I would avoid electrical solder as I am told it is too soft but I have to admit to chucking some end of rolls into the pot.

[Colin SS90]

While rebuilding my SS90 I got totally frustrated at trying to buy front brake, clutch, throttle and choke cables. I tried various sources of genuine BSA parts, but none really fitted satisfactorily, either too long or short inner or outer. In desperation I bought cables that were too long and modified them to fit. I used new nipples to replace the originals.
I remembered my father repairing cables in the sixties and he used Bakers Soldering Fluid No 3. So I took the plunge with Bakers Fluid, lead free solder and a 100w soldering iron. I took my time and measured twice and cut once and finished up with cables that fitted perfectly.
That was three years ago and touch wood all cables have worked perfectly.
So give it a go, but make sure you birdcage the cable end before soldering and I used a Dremel to cut the inner and outer cables which gives a very clean cut.

[Alan wray]

 Im building a B40 STAR, It has 12inch ape hangers on it and i have just started on the cables. I got all new parts, and have splayed the ends out but not birdcaged them. I have used plumbers flux and electrical solder. I have only done the brake end of the front brake cable and faild at the clutch end of the clutch cable. I am wondering if i am going about this the right way.

[iansoady]

Baker's fluid is corrosive and needs to be carefully washed away. I find fluxite paste best. Stainless cables, which are available, are very hard to solder. I get standard galvanised wire and lined outers from Venhill who have a great range.

I use multicore tin/lead solder and have never had a nipple pull off in 50+ years and probably dozens of cables made in that time.

Silver solder has too high a melting point and you're likely to lose the heat treatment of the wire if you're using it. It's not at all necessary.

But if you're not entirely sure then Venhill (or JJ Johnson) will make cables to your measurements.