Repairing my Radiator

Ok, so $20 later I have my unrepairable radiator back in my hands, at least it has been dipped and flushed. These guys really pushed a recore, not even wanting to discuss the condition - just that it needed recored. So, I'm thinking that since I can weld and solder, i have the basic knowledge I need, why not try to repair it. What's the works I can do ruin a bad core?

So anyway I'm looking for guidance on tools to repair it. will my trigger style Weller Solder iron work? I'm guessing that I want plumbing solder rosin core or paste flux? figured I'd toss it into a light colored pan of water and pressurize it and see where it bubbles.

Tips/hits/tool suggestions apprecaited before I dig in tonight?

I dought you will get enough heat from an electric soldering gun unless it is a very big one.

I once had a friend who owned a radiator shop; he used an acetylene torch. That always seemed like a lot of heat to me, but maybe he needed to work fast. I would gently try a propane torch and see how it goes. I agree with Teddy that a soldering gun seems a little anemic.

Ok, so I'll use my "pencil" butane torch. What bout solder? rosin core or not with or without added paste flux?

I use to repair small leaks using acid core solder. clean with wire brush, heat with propane torch.

Anyplace I've ever watched 'em do it, it's a torch, paste flux and plain bar or coiled solder. They tend to flux first, put a little heat to it, before gobbing more flux to it, so that the flux has a chance to run to the inside, too.

I use JB weld or epoxy. Repaired the radiator in my truck at 257,000 miles a few years ago. It now has over 300,000 on it. The water pump quit a few months back but the radiator is still holding water! Good luck.

The big advantage of an acetylene torch is you can use a small tip to concentrate the heat where you want it. I have also had good results with a butane torch.

Cleaning is probable the hardest part and you have a good start on that. Do not use more than 10 PSI of pressure to find the leaks. The way the tanks are shaped on the old style radiators will not take the pressures a modern radiator uses without deforming.

Mark all the locations where you find leaks. Use a small wire brush, emery paper, or a pick to completely clean the area around the leak. Use an acid type flux to cover any areas you have cleaned and are going to solder.

The solder I use is designed for radiator work and has a higher content of acid flux than normal acid core solder. I still use flux paste also because radiators are almost impossible to get completely clean and the extra flux helps carry the crud away from where you need the solder.

Apply enough heat to the radiator to get the solder to flow where you applied the flux. You need to keep the heat to a minimum because every thing is assembled with solder and if you get it hot enough to flow the new solder you can also melt solder where you do not it to melt.

The reason for using oxy/acetylene and a small tip is for localized heating. Most propane torchs
have a wide flame. If you are going to use a propane torch use as small and as fine point tip as you can get. Remember the tubes are very thin & heat up very fast & can be overheated easily. This in itself will cause more problems as excess heating drives the impurities out of the metal you are trying to solder. When this happens you have to let it cool & start the cleaning process all over again.
Good Luck with your indeavor.
P.S. use a #9 acid core solder & if you can get it laco flux.

How about using a large copper soldering iron? The ones you heat in the oven.

Rosin core solder is usually used on electrical or electronic repairs. Best choice here is acid core, then additional flux is not needed.

follow Owen Aaland instructions ,old radiators can be hard to repair but not impossible, if you can soldier ,main thing is to clean the surface and the correct heat an patiance . i've been there with the recore deal quick dollar in there pocket most of the time.