I have been trying to weld pushrods as well as pull pull conections without any luck. I am doing something wrong. I just don not know what.
I have the Hobbico welding iron, also a silver solder kit called Stay brite that has a coil of soft metal (soldering wire) and a little bottle called Stay Clean Flux. I have followed the instructions: heat up the parts to weld with the tip of the gun, hold the pieces to weld together, and then make contact with the soldering wire. The wire melts quickly and does not stay on. When it does, a minor pull to the connection breaks it. I have done it by cleaning the pieces with the supplied liquid and without it, and still same results.
Do I have what I need?
What do I do with it?
Any step by step explanation will be greatly apreciated.

Try cleaning the parts to be soldered with some 240 or 320 gritt
sand paper first, then use the flux.
Some wires , and cables are coated with an oil.
If you can coat the wire, or cable with solder first
(It's called tinning)
then solder them together.

Good Luck
Ralph V

ramireo:

Sounds like you have either or both of two problems.

The base metal to be soldered (not welded) must be at or above the melting temperature of the solder, and it must be clean.

Sand or scrape the two pieces to be joined until you see bright metal. Brush flux on both parts, and heat them with the iron. Then dip the end of the solder in the flux and touch it to the base metal.

If the solder does not melt and flow you don't yet have the parts hot enough. You can sometimes help by touching the solder to the iron, this will help heat flow, and assist in heating the base metal.

It is also possible your iron is not strong enough for the landing gear wire, you need a minimum of 100 Watts for that, but even a 25 Watt should be enough for the pull-pull cables. You might be able to do the push rods with a 25 Watt - the 25 Watt is more for wiring than for construction.

Hope this helps.

Bill.

First... that's "soldering" and not "welding".
Welding actually involves melting weld material into the target material, not Onto it.

With that out of the way, if you truly do have enough heat on the parts for them
to melt the solder, and you're not just melting it with the iron, then they're
still not clean enough. This may be due to some coating on the pieces.

Try hitting the parts with a wire wheel if you have a dremel, or lightly sanding,
then apply the flux to only one part for cleaning, then heat that part, and try
melting the solder onto that one part first. It should take a nice coating of solder.
This is called "tinning". If you do both parts this way, with just a light coating,
then when you get ready to join, it will only take a minimal amount of extra
solder, if any, to get them to join to each other. The other thing is to avoid "cold"
joints. Solder joints should dry bright and shiny. If they're dull or grainy, do it over.
Make sure you don't disturb the parts as they cool off. This is critical.

It helps to have a "third hand" or similar jig, to hold the parts in place for soldering
and cooling. At the very least, a small vise... locking pliers, hemostats, etc...
Anything that can handle the heat of soldering (fingers don't hold up long)
for long enough for the parts to be soldered, and to cool down properly.

It's all about practice, really... and having the right iron (or torch) and solder for
the job at hand. Practice on scraps first... see what it takes to make good joints,
then go to town on the real deal, whatever that is. Soldering is an awesome skill to have.

Had the same problem soldering cabane wires...don't touch the wires with your fingers after cleaning them ...the oil from your fingers may prevent the solder from bonding no matter how much heat or flux you use.
my $.02 worth


Tom

Same here. Just soldered some struts on a Phaeton 90. I found I was using too much heat. Went down to about 75watt soldering iron and everything was ok. Was soldering 5/32" steel rod. Do all the cleaning as described previously. If you use too much heat the flux evaporates and cannot do its job.
Edwin

Can I offer a suggestion here...

A pull pull conection when soldered will have no place for the hot air to go except out the end that you are trying to solder...forcing the solder back out...
If a small hole is drilled towards the threaded end for the hot air to escape and that end heated the solder will be pulled towards the end with the hole in it and filling up the conector and the wire at the same time...
Ya will still have the same strenght out of the fitting...

Stay Brite solder is finikie...too hot and it won't flow...too cold it won't flow...

........... I've been using that trick of drilling a small hole for years and thought no one else knew about it. (although I did try to explain it in an earlier forum). It's a slick trick that works well!

Thanks ED....

Necessity is the mother of invention....