Rust in fuel tank & treatments

[mangocrazy]

I wasn't entirely sure what section to put this thread in, but as rusty fuel tanks are a problem for all types of fuel system, I thought it best to put it in the 'Body' section.

When in France last month, my Beta Spider decided it didn't want to start. Everything seemed OK, but on closer inspection the fuel filter was full of crud dragged through from the tank. The filter was replaced and the car sprang back into life, but this was a clear warning shot that I need to take notice of. Basically I have a rusty tank and it's only going to get worse...

My current thinking is to remove the tank from the car and de-rust the interior (and exterior, while I'm at it) and then seal the interior of the tank with something like GTS1750:

http://www.caswelleurope.co.uk/gastank.htm

As the car is used almost entirely in France, Ethanol in the fuel is a definite concern. French fuel seems to have a higher Ethanol content than UK fuel and I'm aware that this accelerates the formation of rust in fuel tanks. It also can cause problems with fuel lines that are susceptible to Ethanol damage. Copper is one such material affected by Ethanol, as are brass, zinc, buna and neoprene. Materials that are Ethanol-resistant are stainless steel, bronze and Viton. So I'm also intending to replace the existing fuel lines (especially the rubber parts) with Ethanol-resistant alternatives.

Does anyone know what materials are used in the OE fuel lines? And has anyone any experiences (good or bad) in sealing/coating the interior of a fuel tank?

[LanciaNut69]

Hi Mangocrazy,

I've heard both good and bad about tank treatments, but I'm sure it's down to preparation and execution.  Frost offer the POR system, which can work well if you follow the instructions properly.  Sounds like your fuel filter did its job and prevented crap making its way to the pump and carb.  Careful taking the tank out - soak the retaining nuts for a while before removing them to reduce the risk of breaking off.  With the Beta tank, especially the ie/Vx ones, that have a swirlpot type arrangement that doesn't really lend itself to the coating part of the process.  I would be inclined to do the cleaning side of the process to remove the worst of it and regularly change the fuel filter fitted BEFORE the pump.

Hope this helps!

Cheers

Darren

[mangocrazy]

With the Beta tank, especially the ie/Vx ones, that have a swirlpot type arrangement that doesn't really lend itself to the coating part of the process.

Cheers Darren, some food for thought there. Would you happen to know whether S2 Spiders would have a swirlpot type arrangement in the tank or not?

Making replacement of the fuel filter an annual maintenance item is one way of approaching the problem, but ideally I would like to fix the problem at source.

[HFStuart]

Neither of my S2 (Pre f/l) spiders have had them. But the only way to know for sure is to take the sender out and have a peek.

[mangocrazy]

I was over in France for 3 weeks in September, and one of the last things I did was to drain and remove the fuel tank and bring it back in the van with me. Unfortunately I was in a hurry (normally the case, unfortunately) and completely forgot about LanciaNut69's excellent advice to soak the retaining studs/nuts prior to removal. As a result, two of the four studs sheared off on removal. One is possibly excusable, two is not. I was very annoyed with myself when it happened and am still annoyed now...

Anyway, I have a few questions that I'd like people's opinions/knowledge on:

1. What is the best way to reinstate the tank mounting studs? Should I drill out the old studs and use nuts and bolts, or would it be best to get new studs welded on?

2. Is the large rubber tank pad (with holes for flow and return tubing) still available? (I think I may know the answer to this one...)

3. What are the two pipes at the back of the tank (not the flow and return lines) for? One is 12mm i/d, the other is 8mm i/d. I'd also like to know what lengths of each I'll need, as I'm intending to renew all flexible rubber pipes that connect to the tank.

4. What length of 8mm i/d fuel supply pipe will I need to connect to the rigid fuel pipe? I'm intending to blank off the small return pipe, as it's not needed for my Huco pump and won't be needed when I upgrade to a Facet.

5. Where can I get hold of a replacement rubber sleeve/tube to connect the fuel tank inlet to the filler pipe? The only way I could get the old one off was by injudicious use of a Stanley knife...

I'm intending to get the tank sent to Hartlepool Radiators and get them to do their Re-Nu process on it. When draining the tank I couldn't help but notice the large amount of brown-red sludge that came out of it, so it looks like it's not before time that it's done.

[Neil-yaj396]

Can only answer 3. Are these for the breather pipes up to the filler kneck? There are certainly two of these visible in the boot of my car.

My tank is currently secured on three very rusty studs and has a random leak from the return pipe connection so I'm interested in alternative fixings too.

[peteracs]

Hi

For 1 I would drill and tap, then either stud or bolt if you are doing it yourself, or if a garage, then go with whichever is lower cost I guess.

Peter

[mangocrazy]

A friend of mine in France (who also happens to be a very good welder), reckoned that drill and tap was probably the best option.

And I'm still annoyed with myself that I didn't clean/soak the threads first. Completely avoidable...

[mangocrazy]

I took the tank up to Hartlepool radiators on Thursday and as soon as they saw the tank they said 'we've just done one of them!'. So has someone on here had the Re-Nu treatment done to their tank. Anyway, the tank should take approx 2 weeks to turn round. When I get it back I will supply 'before' and 'after' photos and pricing information.

[peteracs]

Hi All

Sure I had seen something about lining a tank with a swirl pot, but cannot find it. I think that they had it done without the swirl pot installed or similar? Not sure if that was the end result as do not have one, but certainly worth looking at if your tank is producing debris.

Peter

[MattNoVAT]

The swirl pot was cut out, the tank was treated and then the swirl pot was welded back in place.

[LanciaNut69]

Hi Peter,

I've just got a Vx tank back from Hartlepool Radiators.  Good and friendly service but not cheap.  Near as dammit 400 quid for the returned tank, but it was in rubbish order with at least an inch of crud in the bottom as well as several holes.  The tank has a swirl pot and I did ask for to be removed, coated and replaced, which looks as though it was done as the internal coating covers everything. 

It's a pretty agricultural looking treatment with plates welded to the outside of the tank.  Not a problem as its under the car, but I certainly wouldn't use it for a Monte tank, which can be seen when you open the engine cover.  Still, better than risking finding a second tank that's in just as bad a nick, plus it's guaranteed.  Overall, I'm happy and it means that my customers car will be heading for an MoT for the first time in 15 years!

Tank outlet pipewise, there are 2 front facing in the middle, 8 and 15mm, which are the flow and return for the original setup - but not used for the new setup.  I've turned an adapter/reducer to go from 15mm down to 8mm, which runs via a filter to a new facet fuel pump to replace the high pressure injector pump.  The return pipe has been blanked off so it could be reinstated at a later date.  There is another 15mm outlet that runs up to the filler neck.  The other 8mm outlet, that runs out of the top of the tank runs to atmosphere via a non-return valve.

I've fitted a filterking filter and pressure regulator inside the engine bay to supply the newly rebuilt carb.  I rebuilt the dizzy too, but that's all probably best mentioned in another post.

Cheers

Darren

[mangocrazy]

Hi Peter,

I've just got a Vx tank back from Hartlepool Radiators. 

That'll be the one they'd 'just done', then... Mine's one from an S2 F/L Spider, so won't have the swirl pot and was probably in better condition to start with than the one you sent up. I'll be 'interested' to see how much it costs, especially as I've also taken a motorbike tank up for them to refurbish...