Leaking petrol tank

[erik]

Need help with leaking petrol tank problem. The petrol tank is mounted with one singel bracket to the petrol tank stand. This not so clever soloution makes this tiny "rivited to the tank" bracket hold all the weight when driving with no hood, which is sometimes necessary when adjusting things. The bracket is rivited and soldered to the tank, my tank is leaking from this bracket and I have tried to resolder it with no good result. I think the bracket was riveted and soldered so the bracket could withstand some stress so I'm not sure if welding the damn bracket is a good idea? What do you think? Anyone got the same problem?

[John D]

Use extreme caution when welding a gas tank.  Gasoline residue can remain even after washing out with water.  It doesn't take much fumes or residue to cause a really serious injury when working with an enclosed tank.  Better to take it to a radiator repair shop with experience in gas tank repairs.

[tim forry]

Erik, definetly at least have the radiator shop hot tank the fuel tank. Then you can braze the crack with confidence. Then you can use a 2 part epoxy called jb weld to seal the area.Works great, but braze first to elimate the stress and movement of the crack. Have done this numerous times with great results.  Tim

[John D]

I am currently restoring my AG-6.  One of the ongoing issues was rust inside the gas tank.  

I bought a gas tank sealer kit, removed the tank and spent a good long day cleaning (hot soapy water, [rinse] strong alkali metal wash [rinse well] Muriatic acid [rinse really well] then Oxisolv, and finally rinse with a quart of Acetone [repeat with fresh qt of Acetone].  

This process left the entire inside a uniform light gray color.  The Oxisolv leaves a phosphate coating to ensure adhesion.

Then pour in the sealer, and coat all surfaces, drain out all excess (no puddles!).  Leaves a white coating.  Work in a well ventilated area, over 60 degrees.  The kit manufacturer recommends venting the tank for at least 48 hours before filling with fuel.

The most difficult part was reaching into the tank - through the port holes in the baffles to clean the inner corners with a scrub brush.  

I had cleaned it out about 2 years ago with a power washer, but not as thoroughly, and didn't seal it at that time.  The gas was discolored again due to rust when I drained it prior to taking the tractor apart this fall.

I expect this will ensure the tank will last another 50+ years, fuel filters will last longer, and result in fewer carburetion issues as well.

[Blake Malkamaki]

If your problem is just a leak around the flange where the drain is and not a rust problem, I would resoldier the flange. If it's riveted, you may have to drill them out before you can unsolder the flange.

It would be best to use a very large soldering iron. If you must use a torch, run a hose from a gasoline engine exhaust into it for at least an hour. My friend does that and has never had a problem. It cooks for fumes out and displaces everything with CO and CO2.

It may be difficult to braze with the old solder on there, plus you stand more of a chance of warping the tank.

[pvcarey]

I use the  exhaust hose from a shop vac, don't use water it will just flout the gas then coat the tank when you drain it out (I learned this the hard way I made a 10 gal. VW tank able to hold about 20 gal.) I use a large soldering iron that is heated with a tourch.
Ron

[Blake Malkamaki]

What advantage would a shop vac have? The idea of the gasoline engine exhaust is the heat and carbon dioxide displace and get rid of all the gas vapors.

On the point of shop vacs, never use one to suck gas vapors out of the tank as they may be ignited by sparks in side the vacs motor. A nice bomb!

[erik]

I tried to solder it but it started leaking right away. Think I have to drill out the rivets and take away all of the old solder and then IÃ,´ll just weld it back together. The tractor is not for daily use just for fun so a good old weld will do fine.
By the way I bought a second OC3 and it has the same problem!!!!
Thanks for all your help.

[pvcarey]

on the shop vac dont suck  blow with the exhaust, its the air flow that removes the gas vapor tail pipe is ok too

[Blake Malkamaki]

Not to be critical of PV, but I would highly suggest not using a shop vac to evacuate the tank. There's just too much chance of an explosion. A soldering iron is the best choice as it has no flame.

Removing the flange and soldering it would be much easier than welding it. Welding will warp the tank and you'll most likely be plaged by hairline cracks for years.

[Log Skidder]

I repaired my tank by emptying the gas and then letting it sit to let the last bit evaporate.  

I think some of these other ideas are good to get rid of all the fumes.

Then I filled the tank with water and used a torch to solder with.  I don't know if it is the best way or not, but it was what I had available.  I drilled the rivets out and then melted the solder holding the bracket to the tank.  Then I used a wire brush head on a side grinder to clean up the tank and bracket.  both looked like they were well tinned with the old solder.  Then I slathered both pieces with solder (plumbing kind) and then soldered everything together with the oxy/actllene torch.  I don't think I re-riveted the bracket on, because I only had pop-rivets available.  I might have threaded some clean wire down one hole and then back up another hole to fill in some of the rivet hole so the solder would nicely bridge the gap.  

I have heard some scarely stories about gasoline staying in pockets inthe seams of the tank and exploding when heat was applied.  


To prevent this from happening again, I would suggest you build a band with threaded rods at both ends to secure the tank to the large tractor bracket.  The same way the hood would.

[Log Skidder]

OOPS. I meant to say that I used a lot of flux, not solder.  It helps keep oxides from forming and lets the solder flow better.

[Orangeman]

Gentlemen:  The restoration of Vintage equipment most always requires attention to the gas tank rust problem.  Here's what I did when I encountered the same problem on a Dynahoe Backhoe.  

I removed the tank, emptied entire contents .... left outside for two weeks during good dry weather.  Proceeded to wash out thoroughly with good soap solution.  

Used a drill to establish a starter hole to open the tank.  Proceeded to remove a section of the tank with a Bosch Metal Cutting Sabre Saw.  

Took the tank to have entirety sandblasted inside and outside.  After sandblasting proceeded to my local metal fabricator and had him heli arc the section that I opened up.  We elected to use the bottom of the tank for opening as the repair would not be so evident after completion.

This detail completed, I proceeded to coat inside with POR - 15.  Results of adhesion of a polymer like POR - 15 directly correlate to the surface prep.  Have done several tanks this way with excellent results. Be safe!!!!!! as others that have posted before ...make d.. sure that the tank is void of fumes by thorough cleaning... your life is too valuable to risk!  

Hope this detail help you out.  Any Thoughts?  Orangeman