How is the best way to fix pinholes in a hydraulic tank.

[madsam]

All, I got my hydraulic tank off today, and sand blasted the bottom to get the rust off. There seems to be a couple of pinholes in the bottom of the tank where it sat of the straps and kept the watter next to the tank. I was thinking on welding them. The tank is empty, but the residue of hydraulic fluid is still flammable. Other than that one spot, the tank looks good.

Has anyone ever fixed one of those tanks, and how?

 

[rosco]

I had a fue tank like that - I had it steamed, then welded each pit. It was time comsuming, but got the job done. You can use TIG, MIG, or Stick Electrode. I would use 3/32", 6010. or 7018. If you have some leakers, there will be others almost ready to leak.

I assume that the tank is steel. What your seeing from the outside is the small end of a crater on the inside (I was thinking there was moisture on the inside, but you said outside. How thick is the material? Welding on a tank that has had petroleum products in it can be hazardous. There are ways to cure them. The ways that involve shortcuts, are dangerous. Taking it some where & haveing it steamed, is the best & safest all around. Then depending on how much experience you have welding, & the type of welder you have availiable, you can weld those spots up, just putting a spot of weld on it. Depending on how many you have, you can probably assume there are more on the inside.

Look inside after its cleaned. if it looks bad inside, have a piece of 16 guage formed that covers the bottom and up on the sides about an inch - weld it all around. Use a synthetic type of material between the bands. That won't harbor the moisture like cotton based straping does. Sorry this rambles.

Lee in Alaska

 

[Stretch44875]

Had the same problem on the Hydraulic tank for my dump. Just welded a piece of plate steel across where the strap had rusted the tank out, welded all the way around so it would seal. Worked just fine.

Dennis

 

[73m819]

my fuel tank on the 819 was like that after i had it steamed cleaned. i striped the paint off the bottom then fiberglased it, still holding good after 3 years

 

[joec]

I have cleaned the tank and brazed the are in. Then cut out rubber strips to put in between the tank and straps.

 

[mangus580]

Depending on how big the holes are, look into some of the gas tank sealer that places like Eastwood have. Its a 2 part system I think, one etches the metal, and one is like an epoxy liner. Its supposed to fill holes up to a certain size, and would probably be the 'easiest' method (aside from Stretches)

 

[Blood_of_Tyrants]

I had a motorcycle gas tank with pinhole leaks from rust. First, I cleaned it thoroughly with hot soapy water and then rinsed. Then I used some naval jelly to remove the rust (I suppose you cold also use rust converter . Then I mixed up some fiberglass resin and poured it into the tank and tilted the tank until all the holes were filled. It held like a champ.

 

[madsam]

Thanks for the input. I looked in the tank, and it seems ok, but it was not clean so it is hard to tell. I don't think the rust was from the inside, just the cotton straps holding watter on the out side. One side was ok, but the other side on the bottom, has 4 pinholes. I have used a tank liner on a motorcycle, but I thought hydraulic oil is more caustic.

So the hardest part is going to be to clean out the tank. The tank on the m816 is so big that dealing worth it gets harder. Then I can make sure there is no cancer inside the tank.

I have a wire welder which does good on thin steel. I will just have to turn it down a little to make sure it won't blow a hole in things. I plan on sand blasting the whole tank first to clean it off. then repaint it with extra paint underneath and maybe rubber bushings instead of cotton.