A lot has been said about using flux, and I can't argue with any of it.
You cannot use an electric soldering gun (or that gee whiz thing they advertised on TV). You need a small propane torch. When using this torch, keep the flame low. Slow is good, even when your heating up a thick thing like the barrel.
I can say there are basically two kinds of common flux used with solder.
The first is rosin core flux, often imbedded in the solder itself.
This rosin core solder is made for electrical wiring and will not work well for brass to steel joints like you need.
The other flux comes in a tube or little can. Without going into what's in it, this is the stuff you need. You will only need a tiny bit of it, just enough to wet the surface of the parts prior to tinning. More is not better.
The metal has to be absolutly clean and free of oils (including your finger prints). The flux will desolve these to an extent, but it is best to take some sandpaper and scratch up the surfaces slightly before fluxing and keep them totally oil free.
Remember, too much heat is just as bad or worse than not enough heat. This is especially important when you flux and "tin" the bottom of the sight.
You only need the part to be about 480 degrees F to melt the solder and that temperature is reached almost instantly on a tiny part if your heating it with a torch.
As was said, to tin the part first clean it, then flux it, then gently heat it touching it with the solder every little bit. When it's hot enough, the solder will melt onto it.
Do Not apply torch heat to the solder. Let the part heat it until it melts.
If you apply too much solder and it forms a bead, take a piece of thick material like denum (or a clean wire brush) and brush off the excess solder.
You are trying to make a uniform, very thin layer of solder on the part, not a big blob. :grin:
When your done tinning, you will have a thin, bright layer of solder covering the entire area you want the joint to be in.
When the parts are cool, put the sight where you want it and lightly clamp it in place with a little C clamp.
Now gently heat the barrel all around the sight, keeping the torch flame away from the actual sight.
After bit, the barrel will be hot enough to melt the tinned solder and a tiny bead of solder will appear at the edges of the sight.
Don't touch a thing!!! Just stop heating the barrel and go get something cool to drink.
Sip it down and when your finished, remove the C clamp. You should now have successfully soldered the sight in place.
zonie
