Any ideas?

Tried with my blow torch and three types of solder and it just won't stick to the brass - even had the brass glowing at one point.

Even managed to flick a large ball of molten solder onto my finger where it stayed until I flicked it off (whilst swearing).

To make matters worse, the blob landed with a splat on my nose cone so as well as the big chuffing bubble on my finger, I burnt my finger tips flicking of the splat.

F'ing disaster!

Pat...

do you need a dfferent kind of flux for brass?

Cheers

Mark

are you using silver solder or plumbing solder?

i'll bring up a brazing rod and the mapp gas. it's worked for most things i've needed it for. failing that, just get an end from MK on friday?

tom

Silver solder, plumbing solder and electrical solder.

Brazing sounds fun!

See you Friday morning Tom.

Pat...

it'll probably be friday before i can next get up to see you anyway, so i'll bring the stuff with me then. we can always have a stab before we set off.

tom

Brass should solder very easily as long as it's clean.
It's more often the cable that refuses to solder as they are often oily.
Also you can get the metal too hot for solder and also oxidise it in the process.
Iwould clean it with wire wool and alcohol, then use plumbing flux (sparingly) if you have some, else cored electrical solder should work.
Dont forget to splay the wire into the cup, you should'nt rely on solder alone to stick, the cable should be fairly jammed in.
Damned if I can find any info on t'internet, obviously a rare craft!

quote:

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Originally posted by indykid
are you using silver solder or plumbing solder?

i'll bring up a brazing rod and the mapp gas. it's worked for most things i've needed it for. failing that, just get an end from MK on friday?

tom

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Once you've got it clean and nicely tinned the last thing we used to do when doing bike cables was to untwist the wire while everything was still molten, this balls up the end then when cooled cut off the excess and centre punch the end to make sure.

Silver solder should work, brazing wil also work but needs more heat which could affect the mechanical properties of the cable

The problem must be you flux, same flux is used for silver solder or brazing -- you need a borax based powder flux or flux coated filler rod.

The way I did it, which worked really well and wall really easy, was:

Clean cable & nipple with degreaser, dip cable in plumbers flux, put cable through nipple, trim to length, splay the end of cable so it's wider. Get a small blow torch, heat the end until the flux starts to bubble, then apply normal solder (or plumbers or silver solder) while holding the cable vertical, the solder will be sucked into the joint and very quickly start coming out the bottom of the nipple.

Let it cool by itself and it's all done.

Do not get the cable to glow red as this will weaken the cable and cause it to snap and go brittle.

^^^^^ ko_racer is exactly right.

there should be no dificult soldering to brass - clean it up and use flux. the problem is the cable - that needs to be cleaned up.

Just to add mate you cannot lead load fibreglass nosecones

Alex

Watch out brazing the brass nipple as the braze and the brass will melt at similar temperatures, you could mould your own nipple from the brazing rod It sounds like you had the metal too hot for the solder if the brass was glowing. If you got it that hot it was not far from running as the surface shimmers a bit then it's too late.

[Edited on 14/6/07 by Peteff]

Most multistranded cable is waxed in manufacture so cleaning it is a bit awkward. Using the correct flux is the most important thing, heating it up like it sounds like you did will only cause more trouble. The flux should clean then the solder should pretty quickly follow it.

Steve

I cut and silver soldered nipples to my Sierra hand brake cable using silver solder flux.

With the off cut I made up a test cable and tensile tested it, and it broke at 330 Kgs.

hth
Paul G

Its also important to splay out the end of the inner cable, so the solder holds it apart, and this helps stop it getting pulled back through the hole when under tension.

Like most jobs, preparation is 90% of a good job.
Clean and degrease the end of the inner cable.

Little tip when cutting Bowden cable. Use a sharp cold chisel , lay the cable on a flat steel surface and give the chisel one sharp tap with a hammer. Will give a clean cut every time with no frayed ends

the bike shop hein-gericke does 2.5 mm cables 2m long with a nipple pack for about 3 quid and adjusters for a pound . find you branch on there web site
http://www.hein-gericke.com/uk/

don't get the cable too warm though, as others have said, it will weaken it greatly as it is high tensile but soon won't be if you get it anywhere near red heat.

(PS speaking from experience and knowledge on this one......I know it will weaken it as I used to work with steels and metallography every day, and I confirmed this by cocking up the same job on my old mk2 granada throttle cable! )

[Edited on 11/7/07 by NS Dev]