Can I weld a Hydraulic Tank?

[Scotty Dive]

I have a 7 gallon hydraulic tank for my splitter and its sprung a leak at the welded in port. I know it can be welded, but my question is whats the proper procedure? Does the tank have to be empty and totally clean of ATF that is in there now?

 

[dfkrug]

The welding is the easy part.

Not only should you empty the tank, you need to get the ATF out of the pinhole(s) that leak.

You don't really need to flush the empty tank since ATF is hard to ignite unless misted. The easiest
way to get the oil out of the pinholes is to heat it with a torch.

After you weld, AIR test to check for leaks. Same procedure as welding cylinders. BTDT

 

[muddstopper]

ATF has a lower flash point than regular hyd oil. Keep that in mind if your going to use a welder on it. My suggestion is empty the tank and flush with soap and water. Clean up around the area to be welded with a wire brush or grinder. Fill with water to the top and then lay on side with the port needing welding is on top. preheat with a propane torch to burn out any oil in the metal around the leak and then mig weld it. Turn it back upside right and look for any leaks. No leaks, drain water and let dry out inside before adding new oil.

 

[SPYDERLK]

Just flush the tank continuously with air while you weld. This will prevent a buildup of fumes from the welding heat. ... I assume you have a crack. If a pinhole or, if you end up with a pinhole after welding, you can use wicking Loctite to seal it.
larry

 

[Scotty Dive]

ATF has a lower flash point than regular hyd oil. Keep that in mind if your going to use a welder on it. My suggestion is empty the tank and flush with soap and water. Clean up around the area to be welded with a wire brush or grinder. Fill with water to the top and then lay on side with the port needing welding is on top. preheat with a propane torch to burn out any oil in the metal around the leak and then mig weld it. Turn it back upside right and look for any leaks. No leaks, drain water and let dry out inside before adding new oil.

Thanks All - This seems to be the safest route to go...Fill with water and weld with the bung up and just a bit of air under it so the water doesn't work like a heat sink. So...will soap and water get the ATF out of there?

 

[Highgear]

I never had any luck welding any tank that had oil in it . No mater how clean you get it the heat from the welder sucks oil into the weld . One job I couldn't stop the leak so the company sent in an "Expert Welder". Well guess what he made me feel a lot better because he couldn't fix it either ! They had to replace the tank !

 

[Gary Fowler]

I wouldn't worry about cleaning it with soap and water, just fill it with water and turn on its side. Heat it red hot with a torch to burn off the oil residue then grind out the old weld prior to rewelding. Just grind out the leaking part, not the whole weld. I would then heat it up again red hot to again burn off any oil that may have seeped inside. Make a multi-pass small fillet weld rather than one thick fillet weld. If porosity happens due to oil, grind it back to clean metal and start over. DONT even ATTEMPT to weld over any pin holes as they will just get bigger. Looks like the original weld had bad cold lap on the outer edge. You may be able to just grind around the outer circle of the weld a bit then heat it up and weld an outer pass on it to fix the leak.

 

[Scotty Dive]

Knocked this out today. Thanks for all your help. I filled it with water almost to the top and used the acetylene torch to burn the area red hot. Also used some Brake clean just before heating it up. Then welded it mig for a couple of passes. some of fluid did catch fire and I bumped the welding table which sloshed the water a bit and it immediately vaporized and scared the crap out of me. After I was done, I blocked off the ports and let it sit with water on its side with no leakage. Now running a small aquarium pump through it to dry it out and will see if I can get some paint to stick to that area of the tank. Thanks again for all the advice.

 

[firemanmike69]

Also used some Brake clean just before heating it up.

If your brake clean contains chlorine it very well could have killed you. Otherwise good work

 

[Scotty Dive]

Guess I dodged a bullet then. I checked and it did not have chlorine, but I would have never had thought to check first. I did do this outside and there was a breeze as usual.