Fuel tank safety

I want to drain my fuel tank for two reasons:

First, I have never done so in the 20 years I've owned the car and must imagine there is a fair amount of sediment and condensation in it.
Second, a few months back my fuel filler cap self-destructed and the inner pressure plate and spring fell into the tank--I'd like to fish out the parts.

I've always heard it's good to displace gasoline fumes with an inert gas--does anyone have a suggestion on what I use and how in order to make things safe?

Unless you're welding or smoking, I don't believe that you'll have any problems. Back in the day (1970s) the standard advice for welding on a gas tank was to get it steam cleaned and only weld while it was still warm. The only easy way I can think of immediately for inert gas is to throw some dry ice into the tank and let it fill with C02. Another option would be that some shops promote nitrogen (for a price) for filling tires.
Got a long pickup tool with a magnet? Got a scope (pulling a blank on the proper term, but the sort of thing that the medical profession uses for a colonoscopy)?
Consider getting it internally coated if you're removing it. I'm no expert and have heard diverse opinions as to how best to accomplish this and if it's worth-while.
I did a DIY liner on our Manx clone VW gas tank, including dropping some chain inside to shake around and knock corrosion etc loose. Maybe not a good idea if your tank is baffled. Have fun - and better have a fuel filter downstream in case you loosen up some stuff that doesn't come out. Doug

Michael Oritt said:

...
I've always heard it's good to displace gasoline fumes with an inert gas--does anyone have a suggestion on what I use and how in order to make things safe?

Click to expand...

Water.

ps. Inert gas ain't cheap.

I don't know that I can recommend a fuel tank sealant anymore. Years ago I sealed a tank on a '32 Ford and really went to great pains to do it right. I never had and trouble with that one but one of the steps was to slush the tank with muric acid and then what to you do with the stuff afterwards. You also had to neutralize it after the slushing. Not too many years ago I sealed the original tank in my Healey. The new kit at that time did not have an acid slushing as one of the steps. I did it the way the instructions said. Within 6 months I had a plugged fuel line in the Healey. It turned out to be some of the coating from the tank got sucked up into the pipe and plugged up at the banjo fitting to the pump. Almost didn't get home that night. but the old tried and true procedure of tapping on the fuel pipe while driving got me home about 8 or 9 miles. I don't think I will ever seal another tank. Also bought a new tank because I could not trust my original tank anymore.

Hi All,

When retrieving my Healey from its close to 10-year slumber in my Father-in-law's garage, dismantling the car yielded a rather porous gas tank. Since, at the time, I had no idea a new tank could be purchased, I cut the top off the tank and laid fiberglass across the inside of the tank left in place. creating a ledge around the opening to mount the removed panel, I also fiber glassed the inside of the panel and left fresh resin on the ledge when I re-secured the panel with screws. Remaining insecure, I decided to encased the outside of the tank with fiberglass as well.

Ten years later, I replaced my fiber glassed tank with a new tank and a friend asked for and still uses my glassed tank on one of his Healeys. My fiber glassing was done around 35-years ago and it is leak free today.

Michael, I am not suggesting this be done as a new tank is reasonably available today. But back then, no internet and few known suppliers, so for the most part you were on your own and that is one way I was able to put my Healey on the road.

Just my thoughts,
Ray(64BJ8P1)

Ray, good thing you replaced the fiberglass tank as any use of ethanol in a fiberglass tank will dissolve the resin into a leaky mess. When ethanol first came on the market at marinas many boats had fiberglass tanks and became floating bombs as the gas leaked into the bilges. Please pass this on to the friend who is using your old tank.

I got told years ago to run exhaust gas into the tank. Cheap inert gas ! Never tried it yet tho

FWIW, we sealed both our Healeys' tanks with the (late) Bill Hirsh's kits, and haven't had any issues. I put a new tank in the BJ8 probably around 25 years and 120K miles ago and the sealant is still good. The kit came with a cleaner/etcher which appeared to be phosphoric acid, which is also used to clean and prep aluminium. Muriatic (hydrochloric) acid is known to cause hydrogen embrittlement. My dad slushed the tanks for what seemed like hours.

Edit: Water is what my welding instructor--an incredible welder--told us to use for welding on tanks. Welders typically have either or both argon or argon/CO2 gas available; you'd want to saturate the tank and keep a steady flow of gas. I just filled a small--not sure of the size, 3 cubic feet maybe--tank for my MIG welder and it was about $40.

Hi Randy,

Wow, what you don't know can kill you. As odd as it may sound, the tank is still fuel tight and I will definitely tell my friend to get rid of the tank for the reasons you stated.

Thanks for the critical information, it is greatly appreciated.
Ray(64BJ8P1)

When removing old gas station fuel tanks, the contractors toss in dry ice. Makes a good inert gas (CO[SUB]2[/SUB]) and is reasonably cheap and available.

Not sure whether those extra parts in there would ever cause a problem. Certainly, avoiding sparks in trying to retrieve anything is an important consideration.

There's an old saying: "if it ain't broke, don't fix it." Unless there's an issue with the tank, or one is venturing far from home and has reason for concern, one could leave it alone.

Another option, if one is concerned about sediment or rust coming through to the engine, is to use an easily accessible fuel filter to catch any debris from the tank. I use that on an old Vette that does not see a lot of use. As another example, I recently brought a Y block 1958 Ford one-ton truck, that had not run for years (or possibly decades), back to life. With new license plates installed, after about five miles on the highway, it coughed and quit. The easily identified problem was that rust from the fuel tank had completely filled the glass fuel sediment bowl, located in the engine compartment. A few minutes later, after emptying the sediment bowl, off we went again. The same thing happened a more few times, with increasing numbers of miles, between events. As perfect a solution as a new tank? Maybe, maybe not. Whatever you decide, you probably know to stay away from coating the inside of the tank with anything; too many negative stories about that.

Thanks all--

I am more concerned with sediment/condensation at the bottom of the tank but figured that its being drained offered a good opportunity to fish out the stray gas cap parts if possible. They might do no harm beyond possibly fouling the sender but neither can they do any good clonking around in there.

More later....

Michael Oritt said:

... They might do no harm beyond possibly fouling the sender but neither can they do any good clonking around in there.

More later....

Click to expand...

I suspect we all know the feeling. It's like having a huge, shady tree in your yard that you love like but you cringe when the wind blows hard.

Bob_Spidell said:

FWIW, we sealed both our Healeys' tanks with the (late) Bill Hirsh's kits, and haven't had any issues. I put a new tank in the BJ8 probably around 25 years and 120K miles ago and the sealant is still good. The kit came with a cleaner/etcher which appeared to be phosphoric acid, which is also used to clean and prep aluminium. Muriatic (hydrochloric) acid is known to cause hydrogen embrittlement. My dad slushed the tanks for what seemed like hours.

Edit: Water is what my welding instructor--an incredible welder--told us to use for welding on tanks. Welders typically have either or both argon or argon/CO2 gas available; you'd want to saturate the tank and keep a steady flow of gas. I just filled a small--not sure of the size, 3 cubic feet maybe--tank for my MIG welder and it was about $40.

Click to expand...

I used the Bill Hirsch sealer on my bugeye tank about 30 years ago and it's still fine. Bill Hirsch was probably the first supplier of a really nice Healey engine enamel in the correct color.

Obviously you need to be careful to avoid any potential ignition sources when the tank is drained but still wet with gas inside. Perhaps you can loosen all the hardware with the tank full, thereby avoiding vapor space. Then drain and lift out. I would purge the tank outdoors with a slow flow of compressed air if you have a compressor and a long hose to avoid fumes near the compressor. Or you could purge the tank while still in the car. Nitrogen is nice and any inert gas will do, CO2 or if money is no object argon work. Part of your tank is filled with air all the time . You'll never get the smell out and unless you are welding as noted above that shouldn't be a problem.

Experience with my original tank showed me that there we literally dozens of spots of pitted metal on the inside that readily became holes in the tank when I used an abrasive blaster at low pressure on the outside. I'm actually glad I did that because I wouldn't have seen these potential leaks if I hadn't. I tried welding these knowing it was to be a temporary solution and rapidly came to the conclusion that a few hundred bucks for a brand new steel tank was looking like the smart thing to do. On old corroded sheet metal like this a pin hole will become a quarter inch hole if you blink while welding. I bought a new tank was happy to send the old tank on its way to the scrap metal pile. Since you are asking for advice I'll offer mine. If the tank is original or even just 20 years old, get a new one.

Re the various suggested procedures I did not plan to do anything more than to remove the drain plug on the bottom of the tank and then snoop around thru the filler using the remote cam I recently bought for this purpose but have yet to use.

I have no idea whether or not the tank is original--I know I have not replaced it since buying the car in 1999. But with all due respect to the good observations made I don't plan to replace it on a recreational basis or until I see evidence of its being compromised.

As you're thinking: drain it; have a look-see with the remote cam. If you can spot the pieces and reach them with a magnetic pick-up (or something equally magic), then do so. Maybe stick a garden hose down the filler (or up the drain) and see what you can wash out. If you've got a hot water tank with a drain valvel (and a lot of hose), think about washing it out with hot water. If you can't drain al the water out, then think about throwing some methyl hydrate in, and blowing it out with compressed air or a backwards shop vac. And note that you're getting a lot of advice from us armchair quarterbacks. Doug

Michael
Just take care when you put the drain plug back, I had to drain my tank to put on a copper washer the PO did not bother to put one in and I had a potential MOT fail after 17 years without any signs of a leak until last year. The tank is home made and is of aluminium and i thought that I had the drain plug tightened sufficiently but it still leaked. I had to gorilla it up to stop the weeping and was worried in case I stripped the thread in the aluminium. I was surprised how much further I had to tighten it.



Bob

BTW you can fill the tank with exhaust gas

The baffles can be problematic when trying to fish items from the tank. Slush coating an old tank is inviting trouble. I steam cleaned mine but it was a lot of work. I also installed a bowl type filter between the tank and the pump.