flex shaft wont take solder

[rchuntlsl]

I am helping a friend of mine, the shaft wont take any solder. I thought he was using the wrong solder, so I grabbed it last night and I took it with me. Well I lightly sanded it and cleaned it with brake cleaner. AND it won't take the solder. I am using the same solder I have used on on 3 of my shafts with no problems. Any ideas???

[Alexgar]

need acid flux to prep

[Steven Vaccaro]

Some black flex cable requires a torch to solder them.

[rchuntlsl]

I have a torch, propane, map, or gas welder.

[rchuntlsl]

Is acid Flux readily available?

[Jeff Wohlt]

Did you sand it goood...down to clean metal and clean with acetone? Then use some flux. You may be getting it too hot and it won't take it.

[siberianhusky]

I find STa-Brite silver bearing solder and flux to be excellent, haven't had as good luck with other fluxes even with the sta-brite solder. Usually comes in a package with solder and flux.

[egneg]

Did you sand it goood...down to clean metal and clean with acetone? Then use some flux. You may be getting it too hot and it won't take it.

[rchuntlsl]

I cleaned it with brake-kleen. I'll try acetone.

I tried heating it with the soldering iron, got it hot enough to melt the solder. Then I tried the propane torch.

[rchuntlsl]

Tried the acetone and sanded it again. The solder just beads up on this thing and drips off. I have never seen anything like it. The flux i tried seems to be useless. The high quality solder has a rosin core, but it is no match for this shaft. I think I will have to try some other flux. The other shafts I have done did not require me to flux them at all. The good solder with the rosin core did just fine.

[HOTWATER]

Sta-brite and a pencil torch is all I have ever used...works perfect!

[rchuntlsl]

Well, I got it and here is how. I used some tinning flux, which did not help much. I took a 1/2 copper pipe cap, heated it up with my torch. Filled it completely up with solder to make a little bath. I hit the shaft with a wire wheel. Heated everything up fairly hot. Dipped the shaft in the pool of solder several times till it finally took. It is not great, but it will never unwind. I then cleaned it all up with the bench grinder and wire wheel, it looks good. Hope I never have that much trouble ever again.

[siberianhusky]

Rosin core solder is for electronics, probably 60/40 lead tin, very soft, at the least acid core would be better.
You really should be using silver solder, no name stuff is available at most hardware stores, the sta-brite flux is the key to good soldering.

[dana]

ive def had issues getting solder take when i got it too hot. after that its a real pain to get solder to take, even after cooling it down,re-sanding and cleaning. kinda weird

[LarrysDrifter]

Where do you buy the Sta Brite?