Discussion Forum - Northstar Chevelle Club

You just sweat it in like water piping dont you..?

clean.
flux
heat with MAPP gas.
apply solder

Chris is correct:
Rosin core for electrical
Acid core for plumbing

I'm guessing the joint fractured right at the "body" of the heater core where the pipe is installed? If I'm not mistaken, those pipes are an annealed brass/copper alloy, and not very malleable (bendable).

Since it's already cracked and you have to re-solder, why not try and de-solder your original pipe (with the correct bend) and solder it in place on the new core?

The tricky part will be keeping the heat from migrating and de-soldering other joints. I'd suggest packing/wrapping the adjacent areas with wet cloths, like heat sinks.

Since the pipes are already tinned, as long as you can get them "dry-fit" it should be easy. Get it dry fit in place, remove, give it a slather with some flux paste, reassemble, then hit it with the Mapp gas or propane torch. There might be enough existing solder on the parts to where it'll just sweat itself in place.

Once it's cool, give it a pressure test with about 15lbs. of air submerged in a bucket of water, to check your work.

The pipe is still attached but the solder cracked half way around right at the seam. It is spankin' new so it's pretty clean. I have heat soak paste I can surround the area with. I have a very fine tip for my torch that I was thinking of using on a very low flame to control the spread of heat. The info on correct solder is helpful, as I think I only have rosin core now. It would cost more in shipping to return it and may be denied warranty, so if I can't get comfortable with doing it myself, I'll take Daves route and have a radiator shop fix it.