Fuel tank cleaning

[Leekade]

After breaking down on my maiden voyage due to an overload of crud in the fuel filter, I decided to take out the tank on my S3. It was pretty straightforward: removed the fuel pipes and top units, removed the 3 bolts, the bracket holding the right bolt, the filler hose and breather pipes. The sump wouldn’t come off but I managed to lift and slide out the tank complete with sump. The tank had been filled with a resin which had deteriorated and was contaminating the fuel. After managing to free the sump with a monkey wrench, it was totally clogged with hardened resin. I managed to remove a lot of the resin but there are some areas I cannot reach. I’ve read about someone putting in screws and leaving the tank in a spinning concrete mixer (the father-in-law did his Austin’s tank in a similar way using gravel!). However, I wondered if anyone has used an acid-based solution to strip the resin? If not, I’ll be buying a load of screws or gravel...

I’ve attached some pictures if anyone’s interested.

Adrian

[johnetype]

That "resin" is hardened old fuel that's left in the tank after the more volatile elements have evaporated over the years.

Knowing that may help you search for ways to dissolve it.

[Leekade]

Brilliant! Thanks, John, I thought it was some sort of sealant used by a PO. I suppose I shouldn’t be surprised, after all, it had stood from 1993 until last month!!

Cheers
Adrian

[cactusman]

Not sure putting it in a cement mixer would be the best idea! As johnetype said it looks like old resinous deposits from old fuel. It may loosen or just turn to gunky goo if you add fresh fuel. Or you could just leave the tank open to entirely remove any volatile residue. What is left will be pretty hard so gently tapping the outside with a lump of wood and it may flake off. Or maybe try a degreaser like gunk or even a soak in parafin....good luck

[Leekade]

Thanks, Julian, I’ll try out your tips.
Cheers, Adrian

[cactusman]

Pretty sure there are companies that will steam clean your tank using high temp steam that will soften and lift off all the goo and gunk....May be the best option short of replacement..

[Leekade]

The companies that I've tried locally, that purport to clean this type of thing, will not deal with petrol tanks now as they cannot obtain insurance!! I also managed to find the little cylindrical-shaped filter in the tank that had detached itself at some point in the past... Every day's a learning experience

[mgcjag]

Hi Adrian...have a look at this https://www.frost.co.uk/cleaner-degreas ... 946ml.html its also used as the cleaning stage for their tank sealer https://www.frost.co.uk/auto-maintenanc ... r-kit.html

[Nickleback]

Hi Adrian,
I had similar problems to you with my petrol tank, so I elected to get it professionally cleaned which in turn lead to 4/5 pin holes being found in the bottom rear corner. Solution was then to get it fully lined and it is now 100% again and re-installed in the car.
If you need to get help, then I can recommend Kempstone Radiators in Bedford who will do it for you. I have no connection with them apart from being a happy customer.

[71 V12]

Hi Adrian,

I have used this company to strip and clean rusty old motorcycle tanks. I have never had a car tank done by them but not too from you and certainly worth a phone call:

Voith Industrial Services
Warwick House,
Watling Street
Wilnecote
Tamworth
B77 5BH

Let us know how you get on.

Kevin

[Leekade]

Hi chaps

Many thanks for being so helpful, I’ll make some enquiries later.
Cheers
Adrian