I just finished the install of my new engine the other day. The engine fired up fine, but my Hardin Marine oil cooler sprung a leak. It was fine last year. All I did to it over the winter was wash it out in a parts washer and repaint it. Its only a couple of years old. The cooler is spraying a small stream of water out, right on the solder joint, where the tank meets the cap. I am thinking of trying to solder it shut with the same stuff you would sweat copper pipes together with. What do you think?

I have had good luck taking coolers to the radiator shop.
Steve

Vinny,
That solder and paste will work.. Propane torch or Mapp will do the trick. Or the radiator shop also..

Cleanliness is gonna be the key, inside and out. Any trace of oil and it won't stick. Rad shops cook their parts in a solution to clean them before doing repairs.