Fabricating A Gas Tank

[Farmall 1066]

Got an old skidloader with a rotten gas tank. Replacement is obsolete.
Original was 10"x12" and 24" long.

Got some 10"x10 3/8" wall square tube I think I'll burn some ends on and add a pipe flange & ****** on top for a filler.
Repaired a lot of tanks, but never built one from scratch.

Anyone got any pointers? No pressure, just has to contain liquid.

 

[rockwithjason]

Epoxy coat the inside for corrosion protection

 

[Thumper68]

I have built a few, I use a liquid gas tank coating from the parts store, don't remember the name, just dump it in and roll the tank around to coat.

 

[yhprum]

If you want to have the same cubic capacity (and space allows) the new tank would need to be 28.8 inches long, not accounting for the added wall thickness.

 

[bigguns69]

I have done what your are planning on doing for decades designing and building OEM construction equipment fuel and hyd oil tanks. Some tricks for success: try to minimize starts and stops with weld bead, always a point of small leakage otherwise, especially with lower viscosity fluids like gas. Pressurize the tank with about 10-15 psi air pressure by putting a Schrader valve in a pug or cap and sealing the tank tight. Spray all the seams down with soapy water or dunk it in a tank if you have one big enough. Looking for air bubbles. Hold the air pressure on the tank for a period of time, 15-60 minutes, if pressure stays constant, you are good. That is what a lot of OEM equipment manufacturers do. You can use a sealer for the inside of the tank when you are done, just pour some in an rotate the tank around till its fully coated internally and pour the remainder out and let dry.

 

[Nor'Easter]

If you are going to coat the inside, try to clean the interior walls before you cap the ends.

 

[theoldwizard1]

Definitely use some kind of sealer on the inside.

 

[Farmall 1066]

Got parts cut today and fit up. Got to find a weld in pipe bung for the filler neck and should be ready to burn it together.
This tank ought to outlast the machine.

Thank you all for your input.

 

[Farmall 1066]

Toughest part was getting the end caps cut to fit inside the tube.
Couldn't find a weld in 2" bung so used a floor flange & gasket and bolted it on.
Welded it up with 7018 and had 3 little pinholes in 80" of weld.
Touched those up and leaving it sit with 20psi...so far no leaks.

 

[az45]

POR15 makes a good sealer - https://goo.gl/kh3R1X

 

[joe49]

1 vote against sealer. Big pain in the *** when it fails. Just as said test your welds and call it good.

 

[Farmall 1066]

I've dealt with the effects of sealer coming loose so decided against it.
This tank rotted from outside in, so not too worried.
Held air pressure for 24 hours, so installed it and happy as a clam.

 

[Ohmthis]

Got a picture of it?

 

[gearhead1]

I’ve made some for my demolition derby cars and used no sealer without any issues. I never had any that leaked either. You’ll be good, just make sure weld are good.

 

[Farmall 1066]

Got a picture of it?

Wish I'd thought to snap a few, but was in a hurry to get it back together.

 

[WoodsTruck]

I just bought a replacement steel fuel tank for my Bronco.

Contemplating sealing the inside before I mount it up. Sounds like there are pros and cons on this.

Any further thoughts?

 

[pb57]

I would never use sealer unless they changed it over the years. Ive cleaned a lot of gas tanks out by sandblasting the inside and the ones with sealer were a big pain. The sealer was always coming loose in them when they were brought to me.

 

[sqznby]

Another vote against sealer.

The majority of the tanks I've made were aluminum but, I never sealed them or the few steel ones. Pressure tested for leaks and sent on there way.

That's going to be one stout tank though haha.

 

[Rick B.]

Me too. I stopped using tank liners on motorcycle tanks many years ago. If the inside of the tank is not perfectly clean and not perfectly dry and not perfectly and evenly coated it will peel. Hell it may peel eventually even if all those conditions exist. Weld it up and pressure test it. If you find any pinholes just solder them up and you'll be fine.

 

[Jazz1]

Another vote against sealer.

The majority of the tanks I've made were aluminum but, I never sealed them or the few steel ones. Pressure tested for leaks and sent on there way.

That's going to be one stout tank though haha.

I would not use any sealers ever. I built tank for my ‘41 IHC. Bent some 14 ga steel and welded the seams then pressure tested
It’s a 50L tank

 

[sberry]

When I was we elding most everyday didn't test them. I remember a welder/helper the company got me, we werebuildid g one and was cold out. Before I catch the guy he tacks and welds one mig. Had about 20 leaks

 

[thunderalley3]

Red Kote fuel tank sealer is like no other tank sealer. I do many repairs on fuel tanks for vintage motorcycles to the point of cutting them apart and welding panels in and Red Kote is always the final step to a tank that doesn't leak and lasts.

 

[kabinenroller]

I have sealed a number of tanks without issues. The trick is to CLEAN the inside of the tank extremely good and make sure it is completely dry before coating it. I use KBS products. They have a prep kit that will etch the inside of the tank and a cleaner that will remove any contamination. If possible I would media blast the tank before welding this will give the sealer some extra tooth to adhere to.
Use a hair dryer to blow warm air into the tank to make sure it perfectly dry before sealing.