Hydraulic Oil Tank Repair

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Well I officially have my first challenging project.  I own a Mustang Skid Steer and it was in for some general maintenance and repairs.  The repair shop said that they found a fairly serious hydraulic leak by the drain plug.  They said that the plug and the area around it must have sustained some damage from a rock or curb?  He said there is a crack in the tank and it will have to be drained and welded.  They won't do the repair so I guess I'm on my own with this one.  Once I drain the tank, what is the safest course of action in order to weld a crack on the tank without creating a burnt skid steer or burnt owner for that matter?   I haven't picked it up yet to assess the damage myself so I'm just going off of his description of it.__________________Miller Dynasty 200DX
Reply:I would take the tank out and have a radiator shop boil it out.  Then I would purge it with Co2 and weld away.  Leave any holes you can open.  Sender.....Usual disclaimerYadda YaddaDavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:How big is this tank?Me!
Reply:Originally Posted by David RI would take the tank out and have a radiator shop boil it out.  Then I would purge it with Co2 and weld away.  Leave any holes you can open.  Sender...David
Reply:Yes it burns very well!  I cut some tubing with a torch that I did not know had hydro in it OMG!  FLAME!!!!!!!Me!
Reply:I can't remember how the mustangs are built but on many skid steers the tank is basically part of the frame and body. If this is the case with yours the only way you can totally sure you're safe is to have the tank steamed out.
Reply:Originally Posted by Me!Yes it burns very well!  I cut some tubing with a torch that I did not know had hydro in it OMG!  FLAME!!!!!!!
Reply:Originally Posted by denrepYes the oil burns.What I mean is just the smoke that vents out of an otherwise closed tank.Just the smoke rising off heated oil residue, the smoke is very combustible.
Reply:I was able to weld on a tractor frame that was hydro filled just by draining the fluid.  I am sure it cooked what ever fluid was in the tube but no "flame" or sparks were present inside.  But a danger is if you burn through you a have a explosion directed at you.  Filling the tank with CO2 or another inert gas will remove the risk of a flash over in the tank since it will have no O2.I used my O/A torch to heat the area I need to weld ( a crack) to slowly burn off any oil that was present.Have a BIG CO2 (40#) fire Ex. on hand and a ABC dry chem also.  Go for the CO2 first since it will not make a mess, but it takes a LOT of CO2 to put out a good oil fire.  The dry chemical will stop it faster but will leave crap all over everything that will need to be cleaned off.Good Luck!Me!
Reply:Well I finally got a chance to look over the problem.  I'm not sure what the JB Weld product looks like since I've never used it, but it looks something like epoxy that is covering the area.  It is leaking underneath that patch.  I'm not going to uncover the area until I'm ready to make the repair because I don't want the oil to begin pouring out.  I still have a couple of projects that I need to tackle before I can take it out of commission.Unfortunately the tank is part of the frame and the leak is adjacent to the right rear wheel.  It means that I'm going to have to figure out a way to get this beast up into the air enough for me to make the repair.  I'm also going to have to figure out a way to get the oil out of the tank enough for me to safely weld this thing up.  I don't know how many gallons the tank is but is large enough that it goes across the entire frame.  I don't own a trailer because I use it on my property exclusively so it will be costly to get this thing to a radiator shop.  I guess if I have to I will though.It would be much nicer to weld this thing on a rack.Miller Dynasty 200DXLincoln SP175Grizzly 14" Band SawRigid CM1450 Chop SawJD2 TN-100 Tube Notcher
Reply:If you use JB Weld to repair anything, be assured that the owner will never call you back for another repair!
Reply:Your oil reservoir probably is not vented; instead a cushion of air is likely  kept trapped above the oil, to keep the tank pressurized. Temporarily you could disable the pressure/vent valve and allow the tank to vent. This will slow the leak until you can make a repair. Keep pump speeds down to avoid cavitation.Consider this for a fix: Get the injury dry, scrub and clean with acetone. Apply a small amount of silicone sealer, just to the immediate damage. Then put a large patch of high-end epoxy over the cured silicone.If you've been running the machine for awhile; maybe you would feel comfortable using the bucket hydraulics to raise the machine. Let it cantilever down on heavy cribbing so that the hydraulic tank is accessible. Be safe about it.
Reply:Epoxy will leak and so will silicone. You will still have to repair the leak with metal after the epoxy leaks again in a week.Weld it- it's easy. Empty the tank and flow CO2 through the tank while welding it. Keep a wet rag over the tank's top vent or filler opening to keep the "white vapor" in the tank while welding. The wet rag will contain the flammable particulate white smoke yet allow the tank to breathe. The CO2 will prevent combustion of anything in the tank. Another alternative is to clean it to shiny bare metal and solder a patch over it. You won't have enough heat to hurt anything in the tank when soldering.
Reply:The welding will take place overhead.  How important would it be if I stuck with argon as opposed to getting helium?  I'd hate to get a helium tank for one small repair.By the way, thank you all for you responses.Miller Dynasty 200DXLincoln SP175Grizzly 14" Band SawRigid CM1450 Chop SawJD2 TN-100 Tube Notcher
Reply:I need your opinions on a new development.  I've been avoiding my tank repair because of the location of the crack as you can tell by the dates of my other posts.I can't be 100% positive about this but I believe the crack is not only on the bottom of the tank but it goes up the side of the tank.  That wouldn't normally be a problem except there is another tank that is welded in place next to the hydraulic tank.  There is only about 1/2" of clearance between the two tanks.Since I can't get a torch between the two tanks, here is my thinking.  Tell me if I'm nuts or right on track.  Since I can't get at the crack from the outside, I thought I would remove a section of the tank on the bottom where the lower portion of the crack is located.  I would cut a hole big enough to get a torch inside the tank in order to make the repair.  Then repair or replace the bottom section that I removed with the crack in it and TIG it in place.What d'ya think?Miller Dynasty 200DXLincoln SP175Grizzly 14" Band SawRigid CM1450 Chop SawJD2 TN-100 Tube Notcher
Reply:Originally Posted by hflwaterski...There is only about 1/2" of clearance between the two tanks....I would cut a hole big enough to get a torch inside the tank in order to make the repair. ...What d'ya think?
Reply:drain the tank below the leek fill the tank with c02 or argon weld itand your good to goChuckASME Pressure Vessel welder
Reply:Originally Posted by chopper5drain the tank below the leek fill the tank with c02 or argon weld itand your good to go
Reply:well we you pull it just do what i said and you should be good as long as it has co2 or argon it will not burn no air no fireChuckASME Pressure Vessel welder
Reply:Originally Posted by chopper5well we you pull it just do what i said and you should be good as long as it has co2 or argon it will not burn no air no fire
Reply:Well, it certainly can't hurt to try the silicone route.  Not to mention that I don't have any helium for my TIG and I'll have to weld over my head while the machine is on jack stands.Miller Dynasty 200DXLincoln SP175Grizzly 14" Band SawRigid CM1450 Chop SawJD2 TN-100 Tube Notcher
Reply:You could probably stick weld in the 1/2" clearance. Wouldn't be easy but I think it could be done
Reply:If this crack is growing, something is causing that, what about making a new tank that you could bolt into place where the old take was, cut part of the old tank off using the sides as mounting for the new tank. Then if you ever need to repair again you can take it off plus if the other frame mounted tank cracks you can remove the hydro tank and get to it. A lil more work but in the future an easier repair.
Reply:Originally Posted by MrRodeoCCwhat about making a new tank that you could bolt into place where the old take was
Reply:I've seen a couple of mustang skid steers and several others that had the tanks being a welded part of the structure. If the crack does truely go up betwwen 2 welded pieces with only 1/2" clearence than there really isn't much other option than to make a window in the outer skin of the tank large enough to work through. Then cleaning out the tank and welding it up shouldn't be that hard. However I would make every effort to totally clean and remove the paint from the suspected area first to make sure you aren't just seeing cracked paint. Making a window would allways be my last resort because it is in a structural area and will kill the resell value of the machine.I repair hydro tanks at least 2 a week if you are concerned about flames and they happen , I usualy steam clean the tank real good then throw in a cup of detergent and cook it again , if the crack in a tank is in a flat area the crack needs to be drilled at both ends to stop groth then I use a mig welder to fill in crack , I spot weld fill the crack to cut down on heat , then weld in patch plate over that , if its the drain plug area then I will either cut it out with a plasma and fabricate and replace the hole piece or  grind out the cracks drill them and weld them back up , I use a mig on most because hydro tanks are usualy 3/16 wall or thinner.