The instructions for the plane I am building say to solder a brass coupler to a length of pushrod wire(throttle pushrod). I have no idea what to use for solder, flux and the amount of heat needed. What is the best way to solder these two pieces together?

You can use regular rosin core electrical solder. You can also use a silver bearing solder "Staybrite" is one brand name, but the regular solder does fine. Just clean the rod very well (fine sandpaper or file)j, clean with alchohol, tin the rod and then solder the coupler on by heating the coupler hot enough to melt the tinned solder on the rod.

Some additional comments- the biggest problem people seem to have with soldering is getting the parts hot enough. You will have to get the coupler very hot in order to melt the solder. I put the wire in a vise and slide the coupler on. Then I hold the red-hot part of the soldering iron tip against the side of the coupler until the solder melts. If you have problems getting the solder to melt then you might need a hotter iron.

I just did some couplers on 2-56 rods, i heated the rod & put a little solder on the rod. Then i took the brass coupler & held it with a pair of pliers & heated the coupler with a butane cigarette lighter, then slide the rod into the coupler, worked great, then heated the rod right @ the edge of the coupler & added a little solder to the joint.

Gil

I typically just slide the coupler on the wire or cable, and then clamp the wire in a small vise. Or actually the little soldering helper I have which has a couple of flexible arms with aligator clips.
Then I heat the brass coupler in the center with a soldering gun. Hold the solder at the end on the couple next to the wire. When the coupler gets hot enough to melt the solder. The solder will melt, and run right up the tube. Thats the nature of solder though it goes to the heat. Thats how you know you have a good solder also. If you touch the solder to the iron, and just kind of melt, and drip the solder onto it. It won't hold for bug squat.

The way to get a proper solder joint is to heat the parts to the point they will melt the solder, not the iron. If the iron melts the solder before the parts are hot enough to do it you will get a cold joint.
Always clean and tin the parts this will insure you do not get a cold joint.
I use a pin torch myself if possible as this always works better than an iron for me. of course this will not work close to flamable parts. PUFF.....SMOKE............FIRE FIRE FIRE

VOICE OF EXPERIENCE.

Miloh.