Ok everyone I'm having a little trouble with what should be a simple task. I can't seem to get my solder to stick to my steel control rods. I'm using a lead free flux and silver solder and have cleaned parts with alcahol and roughend with sand paper but have had zero luck. I think I need some acid based flux but can't locate it anywhere. My Lhs didn't seem to have any answers. What do you all use and where can I get some. Thanks for any help or sugestions.

Maybe you need more heat. Sounds like everything else you did was right.

What is your heat source and what type of silver solder are you using?

Dan

Big thing is a good heat source. I do most of my heavy soldering ,(non-electronic type) using a small Butane torch I found one in Lowes that works well. Also use soldering paste the type the type plumbers use. You have to clean the solder joint after but it makes for a smooth solder joint . If your using a soldering iron you may not have enough heat to do the job.

Like Tim Taylor says "More Power" - in this case, more heat. For big jobs, use a torch. They are inexpensive in any home store, a regular butane one is plenty hot enough. Don't heat the metal so much it discolors; with a torch you could heat it cherry red if you wanted.

If you have an electric pistol-grip-with-trigger type gun (looks like an electric drill) make sure the heating element is clean and shiny too - oxidation on that will keep your wire from getting hot enough, and transferring that heat to your work. A pencil-type iron will only be good for electrical work

Make your wire and/or copper wrap clean and shiny with 400 sandpaper, a little flux (I use a brand called "Sta-Clean" - comes in a little white bottle - sold with silver solder, but the common plumbing paste flux works ok too) and you should be good to go.

This is the same stuff I use and it works great. Since it has a higher silver content and no lead, it requires more heat to melt and flow. A small propane or butane torch will do the trick nicely. Just heat the piece up slowly until the solder starts to flow onto the rod. You might want to take some scrap pieces and practice a bit to get the hang of it. After that you'll be able to do it fast and easy.

well thanks all for the feedback. I guess I should have gave a little more information. I am experianced in the plumbing soldering trade and I am using the same flux my solder is lead free and contains 4% silver also I am using my propane torch. But there is a problem with the heat thing I'm trying to solder a piece of brass tube to the end of my tailwheel gear just above the nylon mount and am afraid of melting the nylon. I've kept the nylon out of the flame but still have slightly discolored the nylon around the steel from heat transfer allready.I really feel that I have enuff heat but cant get solder to flow into joint.any more sugestions? thank-you all.

hotrodmustang
Are you just trying to slide the brass tube over the tail wheel wire like a sleeve?
If so I just use a little epoxy or even CA to hold that type of thing in place

Ok sorry I see what your trying to do. In the view you show. I would just use an over-size wheel coller and put a small flat spot for the set screw to dig into. A little locktite will keep it in place.

also, clamp a vise grip right above the nylon part, it will help act as a heat sink and give you a little more time before melting the nylon...

Have you tried to use the old plumbers trick of wrapping what you don't want to get too hot with a wet rag?

Another trick is a variation of electronic soldering that prevents overheating a heat-sensitive device when connecting it to a circuit board:: clamp an aluminum heat sink to the steel rod as close to the work area as possible. The heat sink can be just a piece of aluminum flashing that's trimmed in such a way that you can easily wrap a portion around the rod with a larger surface like a "flag" to dissipate the heat. Think of something like a 3" x 5" piece of flashing with a 1/4" wide 1" long "tab" coming off one corner. Just wrap the tab around the steel rod, position the "flap" so that it's out of the way and do your soldering. If you have a small "C" clamp, use it to clamp the wrapped tab to the steel rod for better heat conduction (tighter connection to the steel).

Hope this gives you some ideas!

Try this. That rod looks like it might be treated with something. Take that dremel tool and cutting wheel, and grind the part you want to solder. I put my cutting wheel at a 45 degree angle, and just go back and forth. It starts to shine when you get off the surface coating, down to the good metal. Do this all the way around. It's worked a bunch of times for me. After that, flux the rod and tubing and solder away. Let me know if you get it

Alex

Well thanks Alex but the rod is un treated (I believe) but yes I did allready try using a stone to really roughen up the rod with still no luck. I think I just need to try a different solder flux combo. I haven't even been able to tin the rod It just will not stick.

I think you won't be able to get it hot enough for "silver solder" without melting the nylon. "Silver soldering" is really brazing which requires a higher temperature than soldering. Maybe you should try soft solder. it's much stronger than most people think and you won't have to heat it to such a high temp.......Seaplane

I use a small butane torch for everything. I'm an ac mech so i do lots of soldering. if you want to use silver solder and not melt anything get some cool gel.. takes the place of the wet rag and works fine and a peice of copper pipe.. flatten the end of the pipe and cut a notch in a big enough to just fit over the rod.. put it about an inch or two from the joint the copper will take the extra heat and when used with the gel or a wet rag should protect the nylon just fine.. this is how i solder. i flux up the piece, if i am doin say two rods. i do one empty rod first.. i coat the tip where i am making the connection first, reflux and solder it to the other rod. whick works good for wires to. hope this helps