[tapwelder]

You should be able to weld them with out any filler. Seems like you have to practice. Your tip may be too large, however. It will be very difficult if the tip is too large. I have fused 1/16" welding rod with proper tip.

Why are you using coat hanger? You could use 1/8 welding rod the welding rod in place of the the coat hanger. Coat hangers are thin and I am not sure of the composition. Once you get the hang on it welding without filler will be much easier than brazing.

Are you using a neutral flame? You will need to find a neutral flame regardless on what technique you use.

 

[tapwelder]

After rereading your post, are the wires you are trying to fuse together side by side or are you trying to bring them together when after the color change. Clamp the items together. When the color changes to red pull the torch back slightly, anticipating melt through. The maximum heat is at the tip of the inner cone of the flame. Concentrate the heat equally between the items, you should see a small puddle of liquid metal-if it touch both parts, then the parts will be fused.

As you build you must be aware of parts you have already welded because you could burn them as you move the torch. Especially if you braze you could melt a joint, inadvertantly.

Good luck, Practice

 

[tapwelder]

Beginner

If you try to drip the metal onto the joint then you will get a cold weld. A cold weld will fail. I assume you bridge will be tested for strength. I do believe a large soldering gun would work. Be sure to clean the metal by sanding. You must get the hanger (joint) hot enough to melt the solder.

Clamping with pliers (vice grip style) might help reduce burn through since you can concentrate some heat on the pliers. Keep trying the Oxy-acetylene method once you get the hang of it, then it won't be difficult. Play the torch back and forth. Anticipate when it will burn through and remove the heat away from the joint. Hopefully you are wearing goggles (shade 5) because you can look at the flame and judge by color change when burn through will occur.