Soldering a radiator

Recently one of the tubes in my radiator developed a leak. I tried some alumaseal but it doesn't help. Its not a large hole but large enough that it sprays when hot. The passenger side mount also is starting to pull away from the radiator itself. I have a stock brass 1971 radiator.

What type of solder and flux is needed for a proper repair? I can solder just fine (plumbing exp.) but have never attempted brass. Any tips etc.. would be great. Thanks!!

 

Best tip, take to local radiator shop. I have found that their prices are usually reasonable enough to overcome any desire to have to continue to deal with it. if your solder joints are breaking down enough to give you what you describe, then you are in for a long series of small leaks. $.02

 

I would but the nearest rad. shop is 60 miles away and my Jeep is my DD.

 

I put a 4 core radiator in my old truck a few years back, but the bracket that holds it to the core support never fit right. I was driving down a dirt road in the middle of nowhere when "Fzzzzzzzzzzzzzzzzz". What's that noise?? Popped the hood to find my radiator resting on the fan . One of the bumps I hit made it jump off the core support and fall backwords on the fan. The fan took a big swipe out of the top third of the radiator. I managed to limp it home by using a bungee cord to hold the radiator off the fan. I didn't want to blow a bunch of money on another 1 ton radiator, so I decided to fix the old one. I got out the propane torch and bought some plumbing solder and flux (forget what core I got). It took some very large blobs of solder, but I got it sealed up. It looks pretty ghetto, and theres no airflow through the top third of the thing, but it's such a huge radiator there's capacity to spare. My temps didn't change at all.

That's the only radiator I've ever repaired, but if you can solder pipes, you shouldn't have any trouble with a radiator. The repair still holds, although I don't know if there is a better recomendation for what type of solder to use...

 

When doing ANY work on a radiator, dry and clean clean clean is the key. Insulate the surrounding area with a wet cloth so that the heat wont transfer to the good areas, try to achieve a good angle to minimize solder run-off, definitely use flux, solders best friend. The hardest part is to obtain the proper heat without burning up the cores/fins.

Good luck.

 

It's really tough to get the metal clean and dry enough for a good bond, especially in the nooks and crannies.

I use muratic acid as cleaning flux, and it helps a whole lot to get things shiny clean. Never had much luck before I used it. A dremel tool can be handy in prepping the surfaces, too.

After that, conventional plumbing solder and flux.


Pete

 

Its best to use a low temp solder 50/50 (lead/tin) and use muric acid to clean

 

Bought some acid core solder down at Napa. If I have time I'll pull it out and try to fix it this weekend. Thanks guys!

 

Good luck! The next time I fly down I-70 I might look you up.

 

Acid core solder is fine but I'd still prep it with muriatic.

Pete