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Fuel Tank Pinhole- Best Fix? Sealers?

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JamesWilson

JamesWilson

Yoda
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I've a somewhat rusted fuel tank that I'm re-painting.

In stripping off the old paint I've found a pinhole.

The old tank seems to have had a similar problem that was fixed by liberally plastering fiberglass all over the tank's bottom. It looks lousy but seems to work.

There seem to be two other fixes:

1.) Take it in to a welding specialist and have the hole welded.

2.) Use a self-tapping screw and a bit of silicon sealer.

The first will probably take a while and cost more than it should, the second would be quick and easy and cheap.

Should I do it right and get it welded? Or join the ranks of DPOs with the second method? I'm tempted....

Then there's the back-up to both methods- once fixed, the use of some type of tank sealer....

Any opinions on tank sealing/sealers?
 
I don't know much... but I know that last summer my mechanic had my fuel tank "reconditioned" which meant coat the inside of the tank with some sort of protective coating. It had been rusting very badly inside.
 
I take all my tanks to the local radiator shop..they boil them clean and pressurize them to find leaks, then they repair any little holes by brazing them shut, then they line them with a chemical treatment that prevents any rust residue from getting into the gas.
 
haven't messed with the problem myself, but there are liquid sealers that you pour into a tank, move it inside the tank, and when dry, it forms a membrane between the gasoline and the steel. Sold by auto parts stores, or a place called Eastwood, who sells car restoration supplies. https://www.eastwood.com I think, or do a search in a Search Engine. A friend who was restoring a 1965 Renault Dauphine used it and he told me it stopped the leaks. Start by checking Autozone, CarQuest, etc., etc.
 
I don't want to sound like a party pooper - but I do too many gas tanks to not offer this advice: make sure the metal is solid before doing the liner...it might stop leaks for a short time but its not designed to be a leak stop...if you're going to the trouble of removing the tank, either fix it correctly or buy a new one...gas leaks = fires!
 
The boil out by a radiator shop sounds good, and then the pressure test.

I think the tank is basically sound and the pinhole is small. I tried but can't blow any air through it, but there may be grundge inside making it seem leak-proof- for a while.

I've stripped the rest down and it shows a fair "rash" from the rust, but a good anti-rust primer and a coat of good paint ought to make it useable and presentable. Then I'll do the inner sealer/liner.

I'll then mount it on little rubber pads with sealer so no water can sit between them and the tank or boot floor, which was the initial cause of the problems.

I was thinking I'd be told to do it right... so I'm not surprized....
 
If the rust was between the tank and boot floor then does that mean it is in the top of the tank? If so then your fix will probably work. If it is in the bottom, tanks rust from the inside. In that case, the actual rust area is much larger than what you can see from the outside and chances are good that the remaining metal may be to far gone to weld or even braze. Be sure to have it checked really well before reusing it.
 
If you can get a replacement tank, that is the best solution. Fuel tanks corrode from the inside. No amount of patching from the outside will prevent future leaks.

A few years ago, the fuel tank in my XJS Jaguar sprang a leak. It seems the factory installed a pop rivet in the body just under the fuel tank. Over time, the pop rivet wore a hole in the tank. Apparently, this is a known defect on this car, but I didn't know about it until it happened.

My solution was to pull the tank, clean off the area around the hole and seal it with JB Weld. I also removed the pop rivet. No leaks to date (5 years and counting).

This solution is not the best one but it seems to have worked. I wouldn't use it on a rusty tank.
 
Spend the money. Get a new tank. I would bet it will cheaper in the long run. One pin hole means there could be, will be more.
 
Hi JW, I can not refute the wisdom of replacing the tank or having it repaired by the pros. However, If you feel the tank is solid here is a DIY technique I used on mine. First on a good warm day cover the spot showing a good rust rash with a smooth coat of JB weld. Next go to a boat supply and get about a yard ,Meter, of "2 ounce" fibre glass cloth and a good amount of 1/2 Hour curing epoxy resin. Cover the entire bottom of the tank with the cloth and seal it by rubbing the epoxy into the cloth. Going on ten years now and no problems. Note do not use fibre glass resin--Fwiw--Keoke
 
Bruce Bowker said:
Spend the money. Get a new tank. I would bet it will cheaper in the long run. One pin hole means there could be, will be more.
Click to expand...

With a new tank costing ÂŁ450 + VAT at 17.5% that's over $1000 at curent exchange rates.

I'm inclined to try a fix first, and Keoke's suggestion seems a good back-up. The tank now in the car has had fiberglass used on it, but its a really sloppy job and I'm not so sure I'd trust it....

A good clean, a good coating inside and out with some fiberglass to seal it all sounds like a reasonable plan for rather less than a new tank....
 
At that price, I would find another solution too. For a whole lot less than that you can take it to a pro and have a the rusty bottom cut out an new metal welded in. In fact, you should be able to find a competent welding shop that can make you an entire stainless tank to replace it. A couple of years ago I had a leaking 30 gallon aluminum tank on a boat and a shop made me a new stainless one for about $500.

Way short of that, you can use something like the POR-15 treatment to clean, convert rust and seal the inside of the tank then a well applied layer of epoxy as Keoke suggested from the outside and you should be good for many years.
 
Hi JW, thats why my closing note "DO not use Fibre Glass Resin". Only Epoxy Resin will hold and not crack with age.Just make sure the area to be covered is free of dirt grease etc.----Keoke
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]With a new tank costing ÂŁ450 + VAT at 17.5% that's over $1000 at curent exchange rates.[/QUOTE]

Sheesh, at that price you could ship it round trip to Moyer's:
https://www.gas-tank.com/

I vote for checking with local radiator shops. This is the sort of job they used to do frequently, & someone may still be facile with the procedures.
 
Good Grief! It costs me $85 to have one boiled, pressurized, repaired, lined!! & painted!!!
 
I have sealed many many pinholes in gas tanks with lead solder.
After having the tank boiled but before you seal the inside with anything. Pressurise the tank, locate and mark any leaks.
I use a large copper soldering iron, the kind you heat up with a torch. Apply heat with the copper iron to the area to be soldered then apply the flux, let it stand for a minute or two so it can clean and etch the surface. Then reheat with the copper iron and apply the solder.
Note: try not to overheat the area so the lead wont run inside of the tank.
After you have sealed all the visible leaks re pressure test to ensure you have no more leakage.
Once you have sealed all leaks, treat the inside of the tank with rust preventitive and sealer let it dry good. It should last a very long time.
Note: you need a clean dry surface before attempting to solder. Blasting the outer surface with a soda blaster is ideal. Or at least a light sanding of the surface with sandpaper.
Kerry
 
Exotexs said:
soda blaster: coca cola?
Click to expand...

Soda blasting is like sand blasting. Instead of sand it uses baking soda to remove paint. Much more enviro friendly. Does not damage chrome, rubber or glass. I have had two cars blasted, a Lancia HPE and an aluminum bodied race car. Works great. All you have to do is wash the residual soda off.
 
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