TR6 - Rust inside fuel tank

[Josh]

As part of getting to the bottom of continuous fuel smells in the boot, I have completely removed and drained the steel fuel tank from my 74 TR6 PI.

As can be seen in the photos, there is rust in the floor of the tank, which seems to track along the bottom seam of the tank.

I would like to treat the rust, but not sure of the best approach, but feel I obviously need to do something, given the acidic/hygroscopic nature and impacts of ethanol in modern fuels and levels are on the rise.  So this rust will not cure itself by leaving, or just refilling with fuel.

I have considered 3 stage cleaning process; degreaser, etch, then slosh just the floor of the tank. But I'm not sure if just doing the floor is sensible, or feasible, and wonder if it could create a way for the fuel to get between tank and sealer.  My thinking and main reason for not wanting to do a full slosh of the whole tank is that there is no way I can be certain to keep the return fuel pipe that goes down into the swirl pot, which is behind the baffles.  So if t gets blocked, then I'm off for a new tank, with all the issues of Alu Vs Steel.

So are there your thoughts on what I should do here to remedy this and stop further rusting?

[elclem1]

Doesn’t look too bad I have seen a lot worse! I normally change to an ally tank for restoration. A clean tank is a happy fuel system. Lol

Clem

[Josh]

Thanks Clem

So is that a vote for the leave it camp, or replace?

To give context, I should say that I've only owned the vehicle for 4 years, and believe this tank is at least 10 years old.

So hoping to extend for a few more years yet.

[Andy Moltu]

Pretty minimal. Would leave as is.

Coatings for that level of rust probably more likely to cause blockage.

Not bad enough to replace. 

[Josh]

Thanks Andy

[ed_h]

That is pretty minimal rust, Josh.  you can buy a commercial product to clean it, but just a slosh with a solvent and then some phosphoric acid will clean it up quickly, and leave behind a somewhat protective coating.  Or do nothing.

Ed

 

[elclem1]

Josh, It’s a vote for leave as is, I have fitted an in-line strainer Incase there are any big bits of crude floating around, also an isolating valve to make maintenance easier. 

Clem

[Josh]

Thanks all

I have already got an isolating tap to go on it.

I'm still minded that I may give it a chemical clean and slosh just the floor of the tank, to stop it getting any worse.

[Nigel Triumph]

5 hours ago, elclem1 said:

Doesn’t look too bad I have seen a lot worse! I normally change to an ally tank for restoration. A clean tank is a happy fuel system. Lol

Clem

That's my view too. Just check your fuel filter regularly.

Nigel

[Josh]

Nigel,

Thanks much appreciated.

Unlike the game at the weekend - I'm a Quins supporter - unfortunately we let Tigers get too far away to claw it back.  Great game for Tigers though....

[North London Mike]

Half the job is draining and removing the tank, if you're this far along I'd change the tank anyway and take the opportunity to run R9 replacement rubber fuel hose, that's what I did. Lots of people like the alloy tanks for the replacement job.............

However, mixed reports on Alloy, as the tank is a stressed unit and the alloy lugs can get work hardened and then brittle. Steel is more flexible, so I bought a pattern part TR6 steel tank from MOSS, cheap enough. ''Pays your money'' etc etc

 

[SpitFireSIX]

Hi,
Add some ethanol to your tank. It will stop water collecting in the bottom of your ferrous fuel tank and rusting it.
Blue Ethanol is available relatively cheap. Much cheaper than available "Dry Fuel" additive.

Cheers,

Iain.

[Mike C]

In days long past I used to add a litre of so of methylated spirit to the tank if I suspected I had water contamination- it would mix with the water and burn in the engine. 

[John L]

If you take the tank out, make sure you check the drain plug, as it seems to be a contributor to smells in the boot, seems a copper washer is better than a fibre one for making a good fuel/smell seal, and also a viton fuel gauge gasket. https://www.moss-europe.co.uk/gasket-set-fuel-sender-ethanol-proof-293-401.html?assoc=591152

John

[Josh]

John,

Thanks very much.  The tank is out and yes, I am planning to put a copper washer on the drain, plus PTFE tape, as well as changing the fuel sender gasket to a viton one.

I'm replacing the existing copper return that runs from MU to tank with Kunifer tubing.

I'm also changing the old R6 rubber tubing to/from tank/filter/pump to R9 Mocal which I obtained from ThinkAutomotive, who produce it.  They sell various sizes by the metre.  I was very impressed with their service, when I visited earlier this week, as I am geographically nearby to them.  No connection, but I'd certainly recommend them for pipes & connectors, and their bespoke automotive plumbing service.

https://www.thinkauto.com.

One other thing that I have discovered after taking the tank off is that the 2" (50mm) rubber hose fuel filler from the cap into the top of the tank continues to smell significantly after several days off the car.

In summary, I think the smells that I have been expereinceing have been due largely to old aged R6 rubbers throughout the boot.  I look forward to getting things back together again this weekend, and post an update on status hopefully early next week!

[SpitFireSIX]

18 hours ago, Mike C said:

In days long past I used to add a litre of so of methylated spirit to the tank if I suspected I had water contamination- it would mix with the water and burn in the engine. 

I used to add Isopropyl Alcohol when I saw it cheap or work had a drum of it for cleaning.
Don't do it so much now as most pump fuel has about 5% "Dry Fuel" additive anyhow.

[john.r.davies]

Adding alcohol,whether methanol or isopropyl, to fuel if you suspect water in the tank sounds like hosing down a fire with petrol!

[Mike C]

18 hours ago, john.r.davies said:

Adding alcohol,whether methanol or isopropyl, to fuel if you suspect water in the tank sounds like hosing down a fire with petrol!

E10 is 10% alcohol. If you can get it it saves adding alcohol from a bottle to absorb water. But, like all alcohol, it must be used in moderation.

 

[SpitFireSIX]

I used to make my own Ethanol. Best I can do is 90+%. Still has 10% water. We are allowed to make 1000L or maybe 2000L a year for car usage.
Fine to drink but not allowed.

Air still is very inefficient & cost/Volume very high.
Learnt from "The Blue Flame" Manual.

[Mick Forey]

Allegedly, petrol without alcohol can last 10+ years in a tank without significant deterioration. Add alcohol and deterioration starts in a few months. Joy.

Mick

[SpitFireSIX]

6 minutes ago, Mick Forey said:

Allegedly, petrol without alcohol can last 10+ years in a tank without significant deterioration. Add alcohol and deterioration starts in a few months. Joy.

Mick

So fuel can last up to five times more than oil/brake fluid And coolant.
My car uses fuel at least 20 times more than other liquids.

I do not see the problem of E5/10 fuel, concerning the life.

Cheers,

Iain.

[john.r.davies]

When I lived in Denmark, the chemistry students had a still in the basement. Except it wasn't a still it was a fancy filter.    Because what in the UK was methanol and very poisonous, in Denmark was ethanol, just spiked with very bitter vomitogenic substances.   And the chemist knew how to filter it out!   99% pure ethanol!

[ed_h]

Gasoline or petrol is a mixture of compounds with varying volatilities.  Over time, the more volatile parts of the mixture escape if they can.  Given enough time and access to the atmosphere, all that will be left is a resinous "varnish" substance.  This is why old fuel looks, smells, and burns different than fresh fuel.

Even in a perfectly sealed contaner, where the lighter fractions cant escape, there are still likely slower chemical reactions that change the properties of the fuel.

I dont know about other places, but here in the US, it's common to use a fuel "stabilizer" additive for fuel that will sit for more than a month or two.  From my experience, it helps quite a bit.

Ed

[Mike C]

2 hours ago, ed_h said:

Gasoline or petrol is a mixture of compounds with varying volatilities.  Over time, the more volatile parts of the mixture escape if they can.  Given enough time and access to the atmosphere, all that will be left is a resinous "varnish" substance.  This is why old fuel looks, smells, and burns different than fresh fuel.

Even in a perfectly sealed contaner, where the lighter fractions cant escape, there are still likely slower chemical reactions that change the properties of the fuel.

I dont know about other places, but here in the US, it's common to use a fuel "stabilizer" additive for fuel that will sit for more than a month or two.  From my experience, it helps quite a bit.

Ed

Yes, I add Stabil each winter- it makes quite a difference when it comes time for the spring restart.

[SpitFireSIX]

Just drive it. LOL