Farmall Cub

Some advice sought about how to best repair a Cub radiator finned-tube leak. The leak is located on the lower right portion of the radiator tube bank...where a tube passes through the lower copper sheet metal head/panel. Fluid slowly seeping and pooling on the top of the axle casting...and is only noticeable after parking. I tried to solder the leak with the radiator mounted to the tractor but leaking persists. I believe my soldering process was wrong or, with the radiator on the tractor, I could not get sufficient heat on the parts. I am prepared to dismount the radiator this time...could someone share the correct soldering process with me (type of solder, amount of heat, flux, etc)?

Boss Hog recommend a radiator sealer a while back. If Boss say's it is good, you can bet I will use it on my next leak.

I will see if I can find the thread.

Spotlessly clean repair site and plenty of flux. Mapp gas instead of propane if you don't have an oxy/acetylene torch and the tube completely drained so heat from the torch isn't carried away. If all of the above conditions are met, you should have no problem sealing a puncture wound. Cancer may be harder seal, sometimes the whole tube must be removed and the remaining stubs sealed top and bottom.

On a "last leg's" radiator my Farmer Fix goes like this. Be gentle as you can, but get it done.

Needle nose pliers-Remove all fins 1.5" to 2" above and below the leak. A gentle back and forth twist will break the fin, next to the tube.

Set of dyke's or shop scissors- cut out a 1/2" to 1" piece of the leaking tube.

Flat Screwdriver- spread the tubes open where cut. (top and bottom)

Permatex (your favorite color(I like the red))- [Complete one before beginning the other] Squeeze as mush permatex as you can, deep into the tube. Now take the needle nose and pinch the tube shut (1/2"). Then, fold the tube using the pliers width as a guide. Pinch tight, then repeat.(2 folds)

Do the other end and it will not leak

Dale Shaw wrote:Squeeze as much permatex as you can, deep into the tube.

That would create a plug like you have to remove from the end of an opened tube. Never thought about that approach but on a no or low pressure system... Good idea. A lot easier than soldering.

viewtopic.php?f=51&t=71872

Above topic lists the product and method I used to seal up a very leaky radiator on a 154 Cub low-boy.

Many moons ago a neighbor rammed the rear of my 1936 chevrolet with a a1938 buick. We plugged his radiator leak with juicy fruit chewing gum. He just hoped to get home that way. Bob ran the car another 3 or 4 years that way. Had to be early 50's.
I had success sealing bad tubes on a neighbors C. I cleaned the bad tubes with a 22 cal brass wire bush and then with muriatic acid i had put a piece of zinc in. Then I used regular copper tubing flux and soldered using 50/50. It held for a number of years till George died and his kids sold the tractor. Got the zinc from an old dry cell battery. I have been trying to remember why i did it that way and come up with a blank. Only guess is because one of my grand fathers taught me that way.