Soldering flex cable to stub shaft

[dannyual767]

Hello all. I recently purchased an Octura OC64PKG kit for my Dumas Lil Rascal. The kit comes with a .130 flex cable and a bored 3/16" shaft stepped down to 1/8" for small props.

I read the instructions on how to silver solder the thing together. I didn't have a heavy duty soldering iron so I just went to Lowes and bought a nice Bernzomatic propane torch kit. (This is what Octura recommends to use.) I had some silver solder from years ago but I bought some new stuff anyway. Here is what I have and the types of flux:

1. Bernzomatic "silver bearing lead free solder"

2. Alpha Fry specialty siver soldering kit (from Ace Hardware, I think)

a) Bernzomatic lead free water soluble flux (white paste)

B) Alpha lead free silver solder flux (thin, watery stuff)

The flex cable is a gold brass color. I soaked the end in lacquer thinner and then applied flux a. I inserted the cable into the stub shaft and heated the assembly with the torch. The flux heated up real nice and when I thought that everything was hot enogh, I applied solder #1. When it melted, instead of going down into the bored stub shaft, it just balled up and rolled right off the stub shaft :angry: . Next, I tried solder #2 and it did the same thing :angry: .

Next, I tried flux b which is an acid flux and Octura doesn't recommend it. Both solders just rolled right off the assembly. I then tried to just tin the end of the cable with the silver solder. I tried both #1 and #2 and both fluxes. Nothing will stick to that cable. I tried to sand the cable. No go :angry: . Its as if the cable was made of aluminum!

I called Octura and they were surprized. They are supposed to call back after they talk to their cable supplier. I don't think that it is going to do any good. Can anyone offer me some help? At this point, I've spent 30 bucks on this cable assembly and a propane torch and just have a bunch of frustration to show for it!

BTW, several years ago, I tinned the end of a .187 cable with soler #2 and flux b using my soldering iron. It worked great. I don't understand what is going on now .

 

[Richard Dahlheimer]

Hello all.  I recently purchased an Octura OC64PKG kit for my Dumas Lil Rascal.  The kit comes with a .130 flex cable and a bored 3/16" shaft stepped down to 1/8" for small props.
I read the instructions on how to silver solder the thing together.  I didn't have a heavy duty soldering iron so I just went to Lowes and bought a nice Bernzomatic propane torch kit.  (This is what Octura recommends to use.)  I had some silver solder from years ago but I bought some new stuff anyway.  Here is what I have and the types of flux:

1.  Bernzomatic "silver bearing lead free solder"

2.  Alpha Fry specialty siver soldering kit (from Ace Hardware, I think)

a)  Bernzomatic lead free water soluble flux (white paste)

B)   Alpha lead free silver solder flux (thin, watery stuff)

The flex cable is a gold brass color.  I soaked the end in lacquer thinner and then applied flux a.  I inserted the cable into the stub shaft and heated the assembly with the torch.  The flux heated up real nice and when I thought that everything was hot enogh, I applied solder #1.  When it melted, instead of going down into the bored stub shaft, it just balled up and rolled right off the stub shaft  :angry: .  Next, I tried solder #2 and it did the same thing  :angry: .

Next, I tried flux b which is an acid flux and Octura doesn't recommend it.  Both solders just rolled right off the assembly.  I then tried to just tin the end of the cable with the silver solder.  I tried both #1 and #2 and both fluxes.  Nothing will stick to that cable.  I tried to sand the cable.  No go  :angry: .  Its as if the cable was made of aluminum!

I called Octura and they were surprized.  They are supposed to call back after they talk to their cable supplier.  I don't think that it is going to do any good.  Can anyone offer me some help?  At this point, I've spent 30 bucks on this cable assembly and a propane torch and just have a bunch of frustration to show for it!

BTW, several years ago, I tinned the end of a .187 cable with soler #2 and flux b using my soldering iron.  It worked great.  I don't understand what is going on now  .

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The silver braze flux that i use is alpha fry #53500. Tinning the cable like you did, is the way to go. If your parts were clean, chances are, you wernt using enough heat. The torch is also the way to go.Heat the area of the cable with the torch, until the area turns red. Feed in a bit of silver solder. You migt have to sand the solder some, to get the cable into the stub. Now you should be able to put heat to the area of the stub, where the cable is, and just feed in a little more solder where the joint is. Hope this helps. Richard

 

[chunk t]

Dan,

I use a torch as well. :huh: Lacquer thinner :huh: I'm guessing the thinner is causing the probems. I wet a rag with a liquid degreaser and wipe down all of the parts first. Then I hit them w/ the heat to burn off any excess degreaser, before applying the flux.

I always use a liquid flux so it gets whicked into all of the strands in the tip of the flex cable. And just like you did, heat everything up and let the solder get drawn into the stub. The Alpha Fry solder is probably a 60/40 w/o a flux core, which can cold set and ball if you aren't careful (I'm not trying to say you aren't being careful, I still think the thinner is the root cause). Try to find a 63/37 with 1 or 2% flux core for future jobs.

chunk t

 

[RaceCraftBearings]

I am also thinking the lacquer thinner is the problem. Try cleaning with degreaser and try again!

Good Luck!

 

[Nigtmare]

I have silver soldering stuff that have been greased, soped, and dirty with no problems. The trick to sliver soldering is heat. The white powder paste flex that your using is the stuff to use. You need to heat the end of the cable, have your flex mixed with water. Dip the red hot cable into the flex for a few seconds, then add a little more flex, heat it till the flex looks liquidy clear. Apply the solder to where the flex is clear. The solder should melt without anymore heat applying to it. Just put a little amount of solder on it to float through the cable and quickly wipe it with a clean cloth. Now add more flex to the cable and stub, put them together, heat the stub and the cable till its red hot. Apply the solder to the joint and it will absorb right through and into the stub. If you have a little bit of solder sticking out, just grind it off with a sand paper.or the dremel

Nick

 

[dannyual767]

You guys are great! Pretty much everything that y'all are saying is what I found out when I finally got everything together about 1 1/2 hrs ago!

I was told that I was using too much heat so I came back and used less. I also used my water based white paste flux. I found that I could tin the cable end with solder and then insert it into the heated stub shaft. Nick, I wish that I would've had your post before I started. I never would've had a problem! I think that I would've done an even better job and got more solder into the stub shaft as well.

I always use a liquid flux so it gets whicked into all of the strands in the tip of the flex cable.

Chunk, Octura strongly recommends that you don't use an acid flux "which can wick into the cable and cause rusting or corrosion." My liquid flux that came in my Alpha Fry kit is a liquid acid flux.

Richard, my Alpha Fry stuff is #53982.

 

[dave roach]

your not getting the stub shaft and cable hot. you need to use map gas. this will get it hotter faster.

 

[LawlessMan]

You guys are great!  Pretty much everything that y'all are saying is what I found out when I finally got everything together about 1 1/2 hrs ago!
I was told that I was using too much heat so I came back and used less.  I also used my water based white paste flux.  I found that I could tin the cable end with solder and then insert it into the heated stub shaft.  Nick, I wish that I would've had your post before I started.  I never would've had a problem!  I think that I would've done an even better job and got more solder into the stub shaft as well.

I always use a liquid flux so it gets whicked into all of the strands in the tip of the flex cable.

Chunk, Octura strongly recommends that you don't use an acid flux "which can wick into the cable and cause rusting or corrosion." My liquid flux that came in my Alpha Fry kit is a liquid acid flux.

Richard, my Alpha Fry stuff is #53982.

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I use plain old 60/40 solder and a heavy dose of crimping to fasten the flexshaft to the propshaft for the G-23 outboard drive that I build. I do use acid flux, very sparingly, but always follow the soldering with a bath (for the parts!) of bicarbonate of soda and water, and let it soak a while to neutralize any leftover acid. Then I warm the assembly to a couple hundred degrees for a while (or leave it overnight in a warm oven). Lastly, I really soak the assembly in oil while flexing it frequently. I'm trying to come up with an effective method for vacuum impregnating the shaft with oil to be sure there's no chance of rusting. Maybe next year. Another thing I do when soldering a flexshaft is to suspend it so that the solder joint is at the bottom. This seems to help prevent or reduce the tendency of the solder to wick along the twisted strands, away from the joint. Gravity helps overcome "capillary action" somewhat. To suspend it, I grip the upper end in the chuck of my floor model drill press and swing the table out of the way. BTW, a lot of flexshafts are made with wire that has been coated with a dry film lubricant, like molybdenum disulfide (molly-dee) to make the wire winding process easier. smaller flexshafts are made from wire coated with brass for the same reason.

 

[dannyual767]

your not getting the stub shaft and cable hot.

Dave this is what I thought as well so I had the stub shaft cherry red and the solder just rolled off of it. I then removed the cable from the stub shaft and heated it up to red and the solder rolled off of it as well.

Someone on one of my threads told me that I was using too much heat. I went back and applied less heat and was able to get the solder to tin onto the cable. I was heating the stub shaft at the same time so I took the freshly tinned cable with molten solder and inserted it into the heated stub shaft. I then applied a little more solder at the joint and it melted and flowed down the stub shaft bore just like I wanted it to in the first place.

The keys for me ended up being tinning the cable first and not using too much heat.

 

[mark voorhies]

your not getting the stub shaft and cable hot.

Dave this is what I thought as well so I had the stub shaft cherry red and the solder just rolled off of it. I then removed the cable from the stub shaft and heated it up to red and the solder rolled off of it as well.

Someone on one of my threads told me that I was using too much heat. I went back and applied less heat and was able to get the solder to tin onto the cable. I was heating the stub shaft at the same time so I took the freshly tinned cable with molten solder and inserted it into the heated stub shaft. I then applied a little more solder at the joint and it melted and flowed down the stub shaft bore just like I wanted it to in the first place.

The keys for me ended up being tinning the cable first and not using too much heat.

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From what I've read in above posts the part was too hot; cherry red is tooo much

heat. Also once a solder joint fails you need to re-clean with some abrasive and

start over. Re-flux with both parts clean with an abrasive, apply heat from torch

ahead of where you want solder to flow, solder will flow tward heat, just keep

touching solder to part till it begins to flow.

Hope this helps.