Soldering Radiator Neck

super99 · Apr 9, 2021

Does anyone solder their radiators? The Oliver 1550 I bought last December has a new aftermarket radiator, but it has a short neck and the cap doesn't fit right because the neck is too low and rubs on the hood. I have an old radiator that's beyond repair with a long fill neck on it. I'm wondering if I can unsolder the short neck and solder the long neck onto the radiator. Last summer the overflow tube on the 550 came loose. I thought no big deal, I'll solder it back on. WRONG!!All I ended up doing was getting it too hot and the filler neck came loose. There is a lawn mower repair and radiator shop in town that I took it to. He didn't want to mess with it because he was busy with lawn mowers to fix, but finally agreed to fix it. Lawn mower repair must pay better, because he doesn't want to work on radiators very bad. Anyhow, can I replace the short neck with a used long neck??

4520BW · Apr 9, 2021

The trick is to use a small brazing tip. I have the little carry around torch set with the small tip for precision heating. Cleanliness is the trick to getting it leak free as well as using the right Flux. I personally use silver solder with stay silv Flux. The only thing is you have to get it hotter for silver solder so be careful or you will make a big hole and if its thin and corroded use soft solder and stay clean Flux. You can get the solder and Flux at your local plumbing store. Remember clean and clean again!

37 chief · Apr 9, 2021

Like the other post mentioned. Clean is your friend. I have had good success soldering radiators. I use 50 50 solder, and soldering acid, not flux. A hand held propane torch works good. Just heat the brass parts until the solder melts then pull the heat away before it gets too hot. For your first time I would stay away from silver solder. Stan

moresmoke · Apr 9, 2021

Using a soldering copper is what works for me. When I have tried with a torch, even with a very small tip I have had the same experience of things falling apart that I did not want to.

Also liquid flux. I can get it at my local welding supply store.

sms · Apr 10, 2021

I think I used to have an extension neck laying around. Do they still make such a thing?

Michael Soldan · Apr 10, 2021

Cut Acid is needed for doing that job and it should solder fine.

stevieb49829 · Apr 10, 2021

If the size of the new neck doesn't fit the hole, snip slits at the bottom of the neck, about 3/8 inch apart and whatever depth will work, bend out the tabs to make a round flange, and solder over the existing hole. I use those black 4abrasive wheels made by 3M in a drill to get the brass clean. Sanding before you make the cuts makes it easier. They seem to leave a very solderable surface, but they will cut if you are not careful. They also catch edges so sand toward the edge instead of against it.

Soldering Radiator Neck

super99

Well-known Member

4520BW

Well-known Member

37 chief

Well-known Member

moresmoke

Well-known Member

sms

Well-known Member

Michael Soldan

Well-known Member

stevieb49829

Well-known Member

Similar threads