Rust in the petrol tank.

[Hamish Coutts]

Got some work done on my +2s petrol tank. The drain cock was leaking and jammed solid so I got the repair guy to take it off and patch and solder over the hole. That was a few weeks ago when the car was off the road because I was rebuilding the engine. The tank sat in the garage for 2 or 3 weeks before I reinstalled it.

Now I'm back on the road running in the engine .

I took the precaution of fitting a fuel tap and one of those glass servicable filters upstream from the pump when I put it all back together. What I'm finding now is that the filter is clogging with rust particles after about 75 miles running . It's bad enough to stop the fuel flow completely.
Each time I clean out the filter there is about a teaspoon full of fine rust in it. When put back together it's OK for about another 70+ miles, and so on. Mighty annoying - this only happened after the tank repair. Of course, the repair man knows nothing about it and is completely puzzled

Anybody got any idea about repairing this? Is there any point in taking the tank back out and flushing it?. This has been going on for about 4 weeks and 450 miles and shows no sign of going away.
Is the tank knackered? Swearing at it hasn't worked so far!

Regards,

Hamish.

PS - glad I fitted the filter because the pump is a facet red top and would have been jamming all the time otherwise because of the rust particles.

[chrishewett]

Hamish,
I would suggest you try www.frost.co.uk. They have some great products for repairing fuel tanks. I havn't used them myself but have had good reports from others.
Yet another job eh?
Chris

[GrUmPyBoDgEr]

Hamish,
I've heard that empty fuel tanks will rust very quickly under the right conditions.
If your man used "soft solder" to repair your tank, it is more than likely that he used what I know as "Killed spirits" (a flux for soldering steel). This solution of Zinc dissolved in Hydrochloric acid is highly corrosive and every trace of it must be removed after the soldering is done.
Before I rebiult my Elan the steel tank was actually leaking due to rust so I replaced it with an aluminium one.
Sorry not much help!!

[Hamish Coutts]

Yep,

Another 'wee' job and one I hadn't anticipated. By the sound of it my repqir man hasn't washed out the tank properly. The tank had a distinct acidy smell when I picked it up. Wish I'd known what it was then. The rust problem is bad and I'm not sure whether to repair the tank with a sealer (thanks Chris - I hadn't thought of looking at Frost) or to just replace the tank over the winter.

D.J. - can you give me any details on an aluminuim tank. No doubt expensive!!

I might just fit a larger filter in the meantime to help me cope with the problem a bit better in the hope that it'll go away.
Just a thought, would there be any acidy residue left in the tank and would that cause any damage to the fuel tank??

Hamish.

[Hamish Coutts]

"Just a thought, would there be any acidy residue left in the tank and would that cause any damage to the fuel tank?? "


Oops,

Sorry, meant to say would it damage the rest of the fuel system.

Hamish

[GrUmPyBoDgEr]

Hamish,
the company I bought my tank from was in Devon. They used to advertise in "Club Lotus News" but no longer?
Will check my records over the weekend. They were selling the tanks for about 80 GPB+VAT. Much cheaper than anyone else.
Very good quality & "plug & play"
Will get back to you on this early next week. You could check out the TTR website for their price.
Regarding the chance of corrosion to the rest of the fuel system. How long is a piece of string?
Personally I would have thought that the petrol would have diluted it enough for it not to be a problem.
The rust you are suffering from is most likely that which occurred before you filled the tank with petrol.
However I am not a chemist & stand to be corrected.
Good luck!
John

[gwnorth68]

I have had the same problem with my S3 Elan which was put back on the road after 30 years in pieces. But my car has just passed 200 miles without plugging the filter! Twice have had the car stop on the road, burned out the electric fuel pump the second time at well under 200 miles. I now have a NAPA electric fuel pump with a 2"dx2"long pleated fuel filter upstream of the pump. I'm hoping that I'm gradually filtering out the rust which is very very fine paticles of rust. I carry a spare filter and can change it quickly on the road. I flushed the tank repeatedly before installation and nothing was coming out and even now I can drain the fuel and see no evidence of the rust in the drained fuel.
If gas keeps going up you might not want to drive much anyway!

[1964 S1]

I'd try emptying/driving it dry (to the desired location) and then carefully look in the tank by removing the cover plate and fuel gauge sensor. Check the seams as well as bottom. Flashlight and small extended mirror required no doubt! Outdoors with a breeze is best, open the cap...
A leaky tank in a fiberglass car, yikes,,,, Is your battery nuzzled up next to your gas tank like my 69 +2 ?

[brassringfarm]

A friend had the same problem in his Porsche 914. He bought a three-step repair kit from a mail-order supplier that consisted of an etch, a pre-treat and then an epoxy coating that was dumped in the tank. Immediately after, you'd turn the tank around a lot to distribute the epoxy around the inside - checking thru the fuel gauge sender unit with a flashlight. Believe he bought it from Eastwoods in the US.
My old Healey had the same problem, but not as severe. Several flushes of the tank did the trick.
Good luck
Paul Zimmerman
65 s2

[GrUmPyBoDgEr]

Good morning Hamish,

I checked through my records & came up with this:-
Alloy fuel tank for Elan S4 cost a few years ago 120 GBP + VAT.
Supplier S.J. Sports cars, Crediton. Tel. 01363777790.
At the time they were also selling new headlight actuator units
Quite a bit more expensive than the price I had in my memory.

I don't think I will look at all the other bills!!!!!

Regards
John

[Hamish Coutts]

Thanks for all the replies folks - very helpfull.
I now have the choice of:
1. Doing nothing in the hope that it will go away and continue with the hassle of cleaning the small glass filter.
2. Fitting a much larger filter and hoping it will go away
3. Coating the inside of the tank which would hopefully cure the problem
4. Getting a new tank - probably the best solution but undoubtedly the most expensive.

1. is not an option. Think I'll try 2 (filter only costs ?2.50) to see if this tank condition is temporary and will clear up by itself.
Must admit I'm wary of 3. I'm not sure of how long that type of thing will last. It also seems a bit fiddley and if that doesn't work then I'll have no choice but to do 4.

Mmmmm.

Hamish.

[SADLOTUS]

Hi Hamish
I had a leak in my tank from the drain plug the other year and used a petrol-tank-liner-paint type thing from Frost. Works great, took care to make sure it was well distributed around the tank.
Used the car for another two or so years on and off but it's now off the road. Checked with a torch last night, still looks good inside, no metal showing so no rust i suppose. have faith in the product.
hope ths helps a bit.