Petrol tank contamination

[Arthur7]

Hi. This is my first post, having bought my mk1 Ruby a couple of months ago. Can anyone advise how to clean out the petrol tank? It has a thick layer of black sludge in the bottom. I believe the car stood for 40 years before I bought it. Is there a solvent available to dissolve the sludge?

[David Stepney]

You may have to bite the bullet, so to speak, and have it professionally cleaned. I had a similar problem with the tank on my RP and tried all sorts of hinges to try and clean it, none of which worked.

I am not sure that the old trick of putting gravel in the tank and spinning it ( I have seen a concrete mixer used for this) works with a Seven tank because of the internal baffles. However, I will bow to superior knowledge on this.

[Arthur7]

Thanks David. Food for thought!

[MartinH]

Take care, after 40 years the sludge may be holding the tank together! If the base of the tank is corroded then aggressive cleaning will leave you with a sieve.

[andrew34ruby]

I used the gravel and concrete mixer method with no problem. If the bottom of the tank is thin enough to be a problem then simply cut out the bottom, clean through the large hole you have cut, then weld a big patch in. It's easier to get a leak-proof weld with oxy-acetylene, though I have done it with MIG. With MIG it leaked first time, a bit more welding and it was a good job.

[Chris KC]

Don't put a spark or naked flame anywhere near an old fuel tank unless you know what you are doing - no matter how long it is since it held petrol.

[Dave Mann]

I had a similar problem with a friend's RP tank and used Bilt Hamber's Deox C to clean it out.        

[e-richard]

I've been through all of this. Tried everything.
Best solution is a new tank from https://www.compbrake.com/product-catego...car-tanks/
They were very helpful and keen to get it right. I found it best to send them my old tank to match up exactly.

[Arthur7]

Thanks guys for all your advice. I will try the Bilt Hamber stuff first and if that doesn’t work, something more drastic!

[Nick Salmon]

No idea of actual quality but the Compbrake tanks look good.