There was an odd ( but still very simple ) shaped gas tank on the original version of my truck. Unfortunately there are no commercial equivalents available. What is involved in making my own gas tank? Can I use galvanized sheet or does it have to be plain steel? Can I buy a filler neck separately? Thanks Neil
Galvanized not so good. When you weld it the white smoke it puts off is toxic. And you will get galvanize poisioning. Wrenching gut aches!The home cure for this is drink lots of white milk.In my shop I use 16ga hot or cold roll sheet steel. Good luck!
Use regular cold rolled steel. Filler neck is heavy gauge exhaust tubing Fashion a simple sump/baffle inside. Coat the whole thing with plastic tank liner after welding. Well, not the outside. Good luck
I used stainless. I was told the white gas that comes off galvanized metal is cyanide. Galvanized is also impossible to weld so it wont leak. You can also use steel but you should seal it after you are finished. My 2 cents
Plain steel install some baffels . Don't forget a sending unit. If you use a chev unit they have the sending unit and fuel supply in one unit.
Don't use galvanized steel! The welding vapors will make sick or worse.You'll need a sheetmetal box/pan brake to bend it to the proper shape unless you want to weld every seam. A Mig welder can be used but a TIG is preferred for better welds with fewer pinholes. Gas filler tubes are available new from several sources or from the junkyard. Stainless is nice but cold rolled mild steel works fine. Pressure check with soap and water, seal with tank sealer if you have any pinhole problems. For the baffles I cut two pieces of sheet to the same size as the cross section of the tank and sheared (cut) off each corner so I could weld on all four sides of the inside of the tank for more strength (less chance the bottom pushing out when full) spacing them equally in the tank.
Right on. Also, I have used POR-15 to seal many fuel tanks over the years. It is definitely up to the task from my experience. And vintage is right about the brake, the fewer seams, the better. Good luck and post pics.
The mill scale will eventually start to flake off of mild steel and cause all kinds of plugging up problems if you don't coat it with some kind of sealer. Aluminum works good for a tank also. I built one from aluminum for my truck. Don't forget the baffles.
I'll second the notion about using a brake to have fewer seams. I built a tank for my RPU out of 1" angle iron and 1/8 and 3/16 plate and wound up with over 40 feet of weld! I couldn't afford to spend the money a local shop wanted for breaking over the sheetmetal so I went to a steel shop here in Tulsa and bought scrap - hence the 1/8 and 3/16 plate. I welded and welded and welded and welded some more, then tested it. I rewelded the holes and retested it. What a bitch! I used a steel 1 1/2" pipe coupler and recessed it into the top of the tank. I then used an 8" galvanized pipe nipple and a terminating cap for my fuel neck and gas cap. I drilled an 1/8" hole in the cap to allow the fuel to flow easily enough. The only thing I need to do is add a breather tube down into the tank to allow the fuel to flow in easier and faster. I didn't have a sending unit at the time, so I just made a removable plate that attaches to the top of the tank. When I install the sending unit I'll remove the plate and install it into the plate itself. I also installed 2 baffles in the middle of the 32" long tank to help keep the fuel from sloshing forward and backward. I just used pieces of the plate and spaced them up about an inch or so off the bottom of the tank and welded them to the sides of the tank itself. Also, my feed is off the center of the back of the tank. I figured that if I ever got that low then I'd be able to pull the last bit of fuel out of the tank through inertia.
You didn't describe the shape. Are we talking a box? Box with a kick out? Barrel, drum? If any kind of box, you also need to think about fatigue. Fuel tanks carry a lot of weight and a home built sheet metal tank is rarely as stout as a factory stamping. You may want to roll beads in strategic directions to stiffen it up and also consider how it is mounted. You may want to add additional straps, etc. I like making them from 11 ga. sheet steel for this readon. It is heavy, but easy to weld the seams and stout enough to hold up against road wear and tear. Aluminum is worthwhile, but I have seen many needing repair after only a short time. If you think welding on a new tank is a pain, consider one that has already had fuel in it. Remember to leak test your tank with water, alcohol or compressed air before you try gasoline. It will be much easier to fix any pin holes you miss that way.
The shape is like an old fashioned tool-box. Rectangular with the top beveled. It would need to hold around 25 gallons. It will be sitting on the running boards so it will be supported along its' entire bottom. My brake will only reliably bend 20 gauge. Neil
Definitely, but PLEASE don't overdo the air pressure. 10psi in a good sized tank (like yours) can be serious business. Watched a guy just about lose his head when a drum he was pressurizing let go. Luckily, he dodged it and got out with just a broken finger and crapped pants.
A local fab shop can build you a tank in stainless for a good price I imagine. Make up a mockup in poster board or heavy single ply cardboard.
I myself like galvanize poisoning make me feel alive...lol or you can use a good exhaust fan and keep your head out of the plume of toxic gas. It's also hard to paint galvanized sheet metal, without using a metal etching primer the paint will flake off fairly quickly. Otherwise I see no problem with galv. it's cheap and abundant so mistakes would cost ya much. Are most modern tanks galv????? I.D.K anyway. I work with it everyday so I am partial to it. And butter milk works the best, about a half gallon to a gallon.
Cuting and bending two rectangles to form two interlocking 'U' shapes is the way to form a box with the minimum weld, but it's still a longish job. Leak test with low pressure air and soapy water, but if your welding is half way reasonable it's not that hard to get no leaks first time. Food grade stainless, or aluminum and run a little argon in side the box before you start welding so the inside of the welds has some shielding. Alternatively, has anyone ever tried 'hydroforming' a gas tank ? ( in case anyone has not met this, simple idea, you weld two cleverly worked out shapes together, and then using a spare brake master cylinder and some fittings inflate, end up with something that looks not unlike two pressings, same idea as a beach toy, only metal, and water at 1000psi ). Popular for two stroke exhausts, but no reason not to use it for a tank.
I made an aluminium one for the last time for our lakester. I mean the last time. I would in the future go stainless. Al is a bastard if there are leaks, and a non continuous bead is a recipe for a leak. The real hot tip is be very very sure that it doesn't leak before you even THINK about putting fuel in it because you're on borrowed time welding a closed container that has had fuel in it.........fuel leaks out of "water-tight" containers, so give it a bit of pressure......... Stainless, easy to weld, won't foul....won't leak. Gal plate is for hen-houses.
http://www.jalopyjournal.com/forum/showthread.php?t=38970 How to make one out of Stainless, though steel would be the same techniques. No sheet metal brake needed...I like rounded corners.
Good question! I´ve got two probably stupid questions: 1. Why do you need baffles in the tank? 2. And if you build a tank from normal steel do you have to paint it on the inside to prevent rust? Thanks, Florian
I just had mine made from cold rolled steel, and was advised to add a quart of Marvel Mystery Oil inside and spread it around before install. Treats the metal, prevents corrosion. Baffles keep the fuel from sloshing away from the pickup tube when cornering or braking.
20ga would be just fine for a tank that size if you tack welded internal reinforcing ribs in a couple spots to combat bulge. Honestly a bigger concern than tank bulge would be cosmetic dings due to the mounting location, and that alone might push me to a thicker material. You can save a lot of pinhole weld time with liner kits, and they'll also prevent rusty gas issues. Factory metal tanks are plated, a cold-rolled home built tank isn't. Put in a second bung when you add the fuel line, if you don't use it as a return line now, then it's a drain plug. If you decide to step up to FI or a big/bad beast that needs a drag-car style fuel system with return line, you're good to go. good luck
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