I’m having issues finding a suitable gas tank for the 39 Pontiac, so I’m considering building my own. I need one narrower than stock so I can route dual exhaust on each side. I also want to maintain the original RR fender fill location and add a vent to prevent the dreaded gas burp while filling. Can I fab using 18 gauge cold roll steel? Would there be corrosion issues? Would I need to TIG weld, or would MIG suffice? What steel did they use back in the day… 30s through 50s ? Any good tank build threads out there?
I am following here to hear some feedback from others but also have some experience. I likely wouldn't use regular cold rolled steel for just the reason you mention...corrosion. We have dealt with that on fabricated tanks for construction equipment at times when we built concept tanks or otherwise. The inside can be coated, but not necessarily ideal. We do build several tanks out of pickled and oiled steel with much better corrosion resistance. But, we also run diesel in most of those tanks which obviously helps with corrosion. I am planning to do similar soon and will either use the pickled and oiled steel or aluminum for a tank that will see gasoline. And, I believe that mig welding should be fine. That is how we weld all of our production tanks. We also pressure test our tanks to check for leaks. Looking forward to other input.
Yeah, a buddy & I made a gas tank out of Hot Rolled sheet for a Ford Ranger with independent rear out of a Thunderbird - we just got the tank galvanized after we welded it up. Been 4 years and is still looks fine.
Factory tanks are made from galvanized steel, or possibly galvanized after forming and assembly. Typically crimped edges with continuous resistance welds. A home made tank is typically flat sheet, folded, and edge welded. Definitely TIG weld as would produce the least amount of porosity (potential leaks). Working with galvanized sheet would cause trouble with the welds. Best to use bare sheet, and check into having it galvanized or sealed after (I am not a fan of sealers). I have made a couple aluminum tanks and they hold up wonderfully. This one is bout 20 years old and still looks brand new on the inside. A little trickier to weld, but basically the same amount of effort
I made this tank to fit in the rear of my Model A. I believe it is 18 gauge sheet metal, the same I used for body panels. I built a simple buck to fit it around. After I had it all built, I used a POR 15 fuel tank kit. It had a cleaner and then a sealer. It's been in the A for about 5 years with no problem.
I made the fuel tank for my '62 Mercury Monterey Wagon as the original was destroyed, and no one re-pops wagon tanks. I used 18 ga cold rolled sheet, a cheap Woodward Fab bead roller, and some home made hammer forms. MIG welded it from the outside. I used a generic sending unit, and KBS Tank Sealer to seal it up and undercoating (3M Body Schutz) on the outside. Leaked checked with water. Nothing fancy, but it has worked good for the past 10 years with no leaks. There is more information in the cars build thread. https://www.jalopyjournal.com/forum/threads/1962-mercury-monterey-custom-wagon.959751/
Had a tank built in the late 80s, few pointers, don’t tell them it’s going to be gas tank, say it for hydraulic oil, will cost 3 or more times as much if it’s for fuel, if they’ll even do it, liability issues even way back then. Went to a sheet metal shop with dimensions, they bent it up and welded it together out of cold rolled 18 gauge. 300 bucks, no leaks, no paint or sealer, in the vehicle for the next 8 years I owned it with no issues.
I had Ron Pope build the tank for my Henry J, I had him build it out of steel and in hindsight I should've said aluminum. The car set for a few years and the tank got rusty on the top of the inside, I did the vinegar soak but it didn't remove it all. In the end I just bought a new aluminum fuel cell and put it in. You could look up Ron Pope motorsports on the internet for contact info if you want to have it built.
Before tackling a homemade or otherwise tank I would watch for a heavy gauge unit (preferably round if room permits) that anchors with straps around it. My 32 was rear ended & the Tanks brand unit seams held up well but the right-side flange that anchors to the rail ripped the corner open as the frame horn was folded under, could have been catastrophic, I would opt for a boiler plate unit if feasible.
Back in the '70s during the gas shortage I built a saddle tank for my Chevy van. I had the use of a sheetmetal brake so I folded the long sides in to cut down on the TIG welding. I added two baffles and used a transfer switch to switch over to the side tank when I needed to. I used 19 ga. steel and sealed the tank with gas tank sealer.
Boyd Welding will build custom aluminum fuel tanks. I looked into having a custom made tank for my tractor with 8BA flathead. But it turned out that they had a universal that was "close enough" and the price was reasonable. #1 Source for Custom Aluminum Tanks and Accessories – Boyd Welding LLC
I don't have the talent or equipment to weld Aluminum but can weld steel, the 26 gal. gas tank in my avatar Willy's is of steel and lined with sealer. After 20 years still holding strong. It's the shape of PacMans face. No pic's it's all carpeted over....................
When I was in school learning to weld I needed a tank for my 37 and the instructor was up for helping me. Mine was just a rect box. He decided to have me use 1/8" thick as I was learning and had no issues with needing it to be light etc. I did the root weld with 7018 and then capped with with the mig. I never had any trouble with it as long as it was on the road and used but when it sat for years it did end up rusting. If I decide to use it again, I'll clean it and then coat it with RedKote and it will be good for a very long time. I have used the RedKote on motorcycle and ATV steel tanks many times. I made my brothers tank for his truck out of stainless a few years later. It was app 1/16" thick sheet, that's likely what I would do again if building from scratch.
I shudder to think of the fun that would be had with a steel tank that has been welded, where the 'weld' is formed by a series of a gazillion tacks. Chris
^^^^^^^ Yep, You have to block off all the openings pressurize with lite pressure air, mark spots that leak, reweld, do it all over again till no leaks. I only sealed mine with sealer to prevent rust.................. Wouldn't it be same process with Aluminum welding?
Have you looked at the Tanks Inc web site? They have lots of different types of tanks and universal tanks.
I needed a tank for a 41 Packard. 61 olds station wagon was the exact size, fill locale and even sending unit. I had to detail both but it bolted in. Using your chosen dimensions do a Google for tanks that size. It sucked but I found it. Not all searches are alike. My tank came from MN, "something" Tanks USA or such. Good luck. But yeah if you can bend and weld with zero leaks anything is possible. I'd add a baffle. Dead center with 2 good size mouse hole ½ circles front n rear. Quick edit: guys with late 30s and 40s packard 120s were using 50s ford tanks. Someone said country squire, I forget the year. They're smaller than stock. Happy hunting...
I didn't build it but the 79 ElCamino that my son had (and totaled) had a hand made 45 gallon mild steel tank under it and going along with others said that tank did have rust on the inside after I fought with it using it in the bed of my 71 for a while and plugged one inline filter after another apart and took it out and tossed it in the scrap pile. I later cut it apart for the metal for a diy project and it was pretty rusty inside. That tank was made in a welding shop in southern Cali in the 80's as the receipt was still in the glove box.
If your worried about corrosion, stainless is the way to go. I did one for my F1 truck, simple shape, easy to beadroll, bend and weld. 18ga.
I have plans to build a copper tank for my roadster. Don't under estimate how much design and work that will go into it. Whatever material, I wouldn't use Mig Cheers Turns
I made this one 25 years ago, 14 gauge plain old steel, mig welded, 18 gallon. No problems with rust in the fuel, filter is always clean. Heavy enough steel to take a hit I hope. Filler is in the bed floor. I had to stand on it while tack welding the shell together, and even then I wasn't hardly heavy enough to hold it down, 14 gauge is really thick! Two baffles inside splitting it into thirds. Pressure tested, holes marked, welded, pressure test, etc.... till it held air over night.
I think gas tanks were typically made from terne metal, which is steel coated with a lead-tin alloy. Check with metal supply houses in your area to see if they can source it for you.
If you got it in Minnesota the company was probably Auto City Classic. https://autocityclassic.com/ Tanks, Inc. is in Iowa. https://www.tanksinc.com/
Not hard to build a tank. Sealing it is the hardest part. I have made several. Make a fitting for the gas filler out of a capped piece of tube with a tire valve in it. Cap the sending unit and fill it with air. Use soapy water to check for leaks. Aluminum is difficult to work with on the welding end. Stainless and steel are easier to weld. Stainless will give you the longest life. Plenty of places will galvanized dip your steel tank if required. Slosh with ospho and your tank should last as long as you will be worried about. This was for an Amilcar Below was the 1st attempt at a Porsche 904 tank. Aluminum and spot welded baffles.
Have you considered a fuel cell? This is an ATL fuel cell that has the steel outer container and the inner core is a cross linked polyethylene tank (formerly called a rigid bladder) that is filled with a 97% void open cell foam. You might be able to get one from an SCCA racer inexpensively, as the inner tank has a “certification lifetime”, and is required to be replaced after a certain rules specified time. This on is dated 1996 and is still in good condition, however it won’t pass tech due to the age. Oval track suppliers have non-certified tanks for less $$$, such as Speedway, ranging in size from 5 gallons to 32 gallons, which get you the steel outer shell and the inner tank. Some unique sizes and shapes also, like a teardrop shape. What is sad, I have a brand new unused 5 gallon ATL version for my ot project car that I bought in 2002. It has never had fuel in it, but will need a new tank to pass tech whenever I finish the car it was procured for! Oh well…
Great concept but don't forget that Copper work hardens over time from vibration etc and microscopic cracks could develop.
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