View Full Version : carbon steel welding

10-10-2007, 07:27 PM
I have a holding tank that is made out of carbon steel and it has developed two pin sized holes which are now leaking water. This tank is not a pressure vessel it is a tank with a heated water jacket. Anyway I haven’t done any welding in years and that was with a stick welder…. would I have to drain the tank as I would hate to waste all that water?

Would one of those cheap migs from haborfreight using flux core do the job or would I be better off using one of their cheap ac/dc arc welders?

10-10-2007, 08:09 PM
You stand a good chance of blasting a big hole if you try arc welding. The tank is probably rusted thin all over and just happens to have penetrated in a couple of areas.

I would soft solder or silver solder a patch on the outside but the tank will have to be emptied below the hole level.

Old Megawatts
10-11-2007, 07:30 PM
Depending on the temperature, perhaps this method will work. I have seen leaking power transformers patched without draining by puilling a vacuum on the tank and then sealing the hole with one of the catalized patching materials. I also have patched an oil cooler radiator on a large air compressor with this method.


NC Cams
10-12-2007, 09:18 AM
Look into quick reacting epoxy. I"ve seen it for use on fuel tanks and they even have stuff that mixes under water.

Unless you can get the water below the hole, welding is out if the question - liqufied steel and water do NOT like each other AT ALL!!!!

10-12-2007, 10:28 AM
Combine the above two suggestions; pull a vacuum on the tank and slap on a little bit of the water proof epoxy. Keep the extra epoxy so you can repeat the process on other leaks as they arise...which they will with an old tank that has started leaking.

greg b
10-24-2007, 07:56 AM
If the metal is not to thin maby you can push some soap or putty into the hole from the inside just to stop the flow of water and then weld your patch on, the water should keep the soap and putty cool enough so it doesnt fall out while welding, stick tig or mig should be better as the heat sink for oxy may be to much.With a bit of luck there will be no cracking,im assuming the holes are at the bottom of the tank ,good luck regards greg.

10-24-2007, 02:51 PM
thanks all... I had a professional come in a work on it and he welded it with a mig after we drained it as the pin hole was on the bottom of the tank…