Heat Exchanger Repair

[parkhil2]

I have a very small leak around one of the inlets on the FW side of the heat exchange. I was told that with some flux and solder I could fix this myself. I have the ability to solder, but am wondering this is a good solution. Has anyone tried this before?

Thanks

[bostonhatteras]

are you refering to the actual heat exchanger unit, as if it were removed from the heat exchanger tank? other than that, I believe everything would be gasketed. the only brazed joints I can think of are the raw water pipes transitioning from pipe to flange. bring it to a radiator shopand they can pressure test and do the repair.

[REBrueckner]

Have not done it myself, but I'd check to find if it's traditional low temperature soft solder or a deluxe type like silver solder. Also, you should try to match the solder type so as to avoid local corrosion due to dissimilar metals. Usually an old repair depends on the initial cleaning before soldering....so I'd scrub with a wire brush, maybe use a touch of acid and then rinse before using solder flux for the final cleaning....

I have soldered copper based exhaust risers with everyday soft solder and that held just fine for over 8 or ten years.

A fresh water heat exchanger solder repair would have to hold a bit of pressure, usually about 7 or 8 lbs in old two cycle Detroits....not much.....and that's determined by the pressure cap you choose. Considering soft solder easily holds household water pressure in the 30 to 40 lb range, that should not be an issue....household water temps are typically in the range of 140 max while coolant might get to around 180....so those should not be issues...

[rsmith]

I have a very small leak around one of the inlets on the FW side of the heat exchange. I was told that with some flux and solder I could fix this myself. I have the ability to solder, but am wondering this is a good solution. Has anyone tried this before?

Thanks

I had the same deal on the 12'n's small crack at the flange that would just show a stain of dampness took it to a marine welder and prop repair guy. who tiged it made it worse the guy redid it 3 times before I took it to the shop that does our industrial work the shop manager said the guy overheated the metal and made it brittle I ended up jb welding it until I found a green part over on the Missippi.$2400 15 years ago.If i know what I know now I would have left it alone and let it fix it self. If your not losing water I wouldnt worry unless you have a welder that specialises in exotic metals.