Keith66 Posted August 28, 2023 Report Share Posted August 28, 2023 Hi All I’ve restored my car and one of the jobs a few years ago was to sort the fuel tank as it was internally pretty rusty, so restore or buy new. Well I looked into it and though I’d give a clean-up a try and see how it went. So I used both nuts and bolts and gravel with some water in the tank to get rid of the worst of the rust scale. That leaves lots of surface rust so I used 5litres of 45% Phosphoric Acid to get rid of that and the results seemed great (SeePic) nice clean steel. The bonus is (should have been) that phosphoric acid leaves the surface covered in a phosphate which resists rusting again, supposedly!! But a few years later with the car more or less finished its been driven a few times (few miles) but its stopped twice just like its run out of fuel (it hasn’t) so something else it causing fuel starvation symptoms. Had all of the Pi tested and checked and its all spot on so I look into my fuel tank as best as I could and saw, what looks like rust!!! It looks weird, though its wet with petrol. I removed the filter (CAV type) and its full of rust particles so I’m thinking that is the problem. So questions assuming it is the problem, Is my old tank junk now and do I simply need to replace it? If I de-rust it again is there a better way, tho phosphoric acid seemed to leave a really clean surface. Whats causing the rust? The water content of E5 petrol or just condensation and how can it be kept at bay? If I replace the tank with a new steel one are they treated or if just mild steel won’t they just rust the same as my current tank? Cheers Keith Quote Link to post Share on other sites
John Morrison Posted August 29, 2023 Report Share Posted August 29, 2023 Think that tank is pants Keith, you'll always be at that. I think most replacements last few years have ben ally ones, though there are some concerns about these and Ethanol, can't remember hearing of a problem so far, John. Quote Link to post Share on other sites
Paul Hill Posted August 29, 2023 Report Share Posted August 29, 2023 (edited) Because I had what you have on my old tank I just switched it out for this £230 job done no more problems. It also had the bigger outlet for the Bosch pump The tanks were made just a mile from where I live, I see you are in the West Midlands so just down the road from me Edited August 29, 2023 by Paul Hill Quote Link to post Share on other sites
kcsun Posted August 29, 2023 Report Share Posted August 29, 2023 you could try this https://www.rust.co.uk/product/slosh-fuel-tank-sealer-new-formula-2/ kc Quote Link to post Share on other sites
rcreweread Posted August 29, 2023 Report Share Posted August 29, 2023 2 hours ago, Paul Hill said: Because I had what you have on my old tank I just switched it out for this £230 job done no more problems. It also had the bigger outlet for the Bosch pump The tanks were made just a mile from where I live, I see you are in the West Midlands so just down the road from me Paul - I’m guessing that’s an Alicool tank - sadly they closed down some time ago, so not available any more cheers Rich Quote Link to post Share on other sites
keith1948 Posted August 29, 2023 Report Share Posted August 29, 2023 Hi Keith66 Looking at your photo of the filter, i'm not sure that looks like rust. Looks more like bits of a resin like material. If it fizzes in acid then rust but if it doesn't then possibly resin. Could this be muck from the garage pumps last time you filled up with petrol? I can't see similar colour bits in your tank. Had problems with a 4A and a 3A after both filled up at a supermarket garage in Wales some years back. Fresh petrol from a different garage solved the problem. Keith1948 Quote Link to post Share on other sites
Waldi Posted August 29, 2023 Report Share Posted August 29, 2023 Pictures can be mis-leading but the tank looks clean to me. Could well be a residue that came in during filling, as Keith(1948) says. Waldi Quote Link to post Share on other sites
rcreweread Posted August 29, 2023 Report Share Posted August 29, 2023 Guys - according to Keith, the poster, the photograph of the "clean" tank was just after it had been cleaned with phosphoric acid - it has then been put to use for several years, after which it's stated "so I look into my fuel tank as best as I could and saw, what looks like rust!!! It looks weird, though its wet with petrol. I removed the filter (CAV type) and its full of rust particles so I’m thinking that is the problem." I don't think fuel contamination is the issue - if it was me, I would cut my losses and get a new tank, and in terms of a choice between steel or alloy, alloy every time - claims that alloy tanks suffer more corrosion than steel from ethanol are questionable, but what isn't questionable is that the water in ethanol will have a much lesser effect on alloy than steel - the choice is yours but I know what I would choose Cheers Rich Quote Link to post Share on other sites
Martin50 Posted August 29, 2023 Report Share Posted August 29, 2023 Keith, I would try to flush the tank and see if more particles come out. Not sure if you can do that with tank in-situ but the more rigorous the flush the better and would give you more info on status of the tank The filter by the looks of it has done its job and quite likely caused fuel restriction. If more particles do come then as the prior comments its probably better to cut your losses and replace the tank. But if the flush is clear, maybe you’ve seen the worse of it? Not sure how long you’ve been running car since the original tank cleaning. Just thinking to try another test before paying out for expensive new tank. Just a thought. Quote Link to post Share on other sites
Paul Hill Posted August 29, 2023 Report Share Posted August 29, 2023 My Alloy tank as been in three years now with no evidence of any problems with ethanol. Quote Link to post Share on other sites
Z320 Posted August 29, 2023 Report Share Posted August 29, 2023 Hi, mostly forgotten is the stiffness the steel petrol tank give the rear car body. Knowing how different steel and aluminum acts and reacts my choice is to keep my original steel tank. Ciao, Marco Quote Link to post Share on other sites
keith1948 Posted August 29, 2023 Report Share Posted August 29, 2023 Don't know if this link is of any use but suggests particles like in your photo might not be rust but might be inside of 'rubber' fuel pipe being affected by ethanol in fuel. Are your hoses modern ethanol resistant? https://www.thehulltruth.com/boating-forum/773757-looks-like-rust-particles-fuel-water-separators.html Quote Link to post Share on other sites
Pontious Posted August 29, 2023 Report Share Posted August 29, 2023 11 hours ago, kcsun said: you could try this https://www.rust.co.uk/product/slosh-fuel-tank-sealer-new-formula-2/ kc +1. I had a Good result with Slosh. Useful advice from the manufacturer when I called them too. David Quote Link to post Share on other sites
stuart Posted August 30, 2023 Report Share Posted August 30, 2023 16 hours ago, Z320 said: Hi, mostly forgotten is the stiffness the steel petrol tank give the rear car body. Knowing how different steel and aluminum acts and reacts my choice is to keep my original steel tank. Ciao, Marco A firewall will add the missing stiffening Stuart. Quote Link to post Share on other sites
Keith66 Posted August 30, 2023 Author Report Share Posted August 30, 2023 Hi Guy’s Many thanks for the replies. As Rich said the first photo of the tank was just prior to installation taken mid 2019, with the installation done late 19, so it was a clean as I could make it at that point. The car has only just been made usable but the first lot of petrol has been in for ages to get the engine running and do an initial shakedown run of maybe 10 miles. After finishing a few things off recently I again took it out for a short trip and all was fine. So as the car seemed roadworthy I put about 3 galls, say 2 weeks ago to take it out for a longer shakedown run, planned to be 50 or 60 miles but in that time it stopped 3 times and it took some messing and leaving overnight to get it home. So its only covered about 75 to 100 miles since first being driven over 6-18 months. As the pump (Lucas) was tested and was spot on it was suggested the problem was between the tank and the pump hence stripping the filter down and finding all of the junk, which I assume is restricting the fuel flow enough to cause the pressure to fall. I also drained the tank and more bits came out. I assumed it was rust until Keith1948 suggested resin. So I’ve put some of the bits in the Phosphoric acid and at the moment its doing nothing just sitting there not fizzing. My first pic of the inside of the tank was taken with the tank out and its really difficult to see inside with it in the car so I got one of those endoscope cameras, only a cheapo USB one that plugs into a laptop so the images are not great. But it does not look that rusty but something else is in the tank. I also had a look in the fuel hose but the camera won’t go far in and it looks ok, with just a few minor cracks. So is that the resin and what is the cause and solution? Cheers Keith Quote Link to post Share on other sites
stuart Posted August 30, 2023 Report Share Posted August 30, 2023 Second picture looks like rust. either way its a failure of the coating. I would ditch the tank as you`ll never get it clean enough to rely on now. Stuart. Quote Link to post Share on other sites
mattyb Posted August 30, 2023 Report Share Posted August 30, 2023 While not much help to Keith, when I cleaned the petrol tank of my Tiger Cub that had been stood for 10 year plus, I used Brick acid (hydrochloric acid) with a load of old nuts and bolts to agitate the rust, hosed it out with water, dried it and then used "POR15" . Inside of tank has been perfect for a good few years now - The only caveat is that the cleaning and POR15 treatment has to be done all in the same day, other wise the tank immediately starts to rust again - POR15 is very "runny" but seems to coat the inside of a fuel tank very well - I'll be treating my TR6 fuel tank with POR15 cheers Matt Quote Link to post Share on other sites
Brian Moss Posted August 30, 2023 Report Share Posted August 30, 2023 Is there anyone making stainless steel tanks? I had one made for a prewar sports car project of mine to avoid problems with modern fuels. I know that one Alvis specialist has had some made for some of those cars. Quote Link to post Share on other sites
PodOne Posted August 30, 2023 Report Share Posted August 30, 2023 Personally Kieth after looking at my own steel tank and the cost of chemicals, POR15 and the time and the potential for further rusting as there is no guarantee of it all been fully removed and then recoated with POR15 I bought an aluminium one. I'd suggest trying to salvage the old one will lead to further problems down the line usually late at night with heavy rain! Andy Quote Link to post Share on other sites
Mark V Posted August 30, 2023 Report Share Posted August 30, 2023 Colin at CTM used to make stainless steel tanks for the TR6, I've got one but it was brought several years ago. Maybe worth a call to see check. Mark. Quote Link to post Share on other sites
Keith66 Posted August 30, 2023 Author Report Share Posted August 30, 2023 10 hours ago, stuart said: Second picture looks like rust. either way its a failure of the coating. I would ditch the tank as you`ll never get it clean enough to rely on now. Stuart. Stuart, yep there is def some rust in there but the majority seems like something’s else, especially as the bits haven't dissolved in my acid yet. So has anyone ideas on what that is? If the tank is past it I will get another but I was concerned about rust in a new mild steel tank, but you mention the coating having failed, are they made from a coated sheet? I’d assumed simply pressed mild steel which would rust fairly quickly, as steel sheet does. Have you had any problems in new(ish) tanks? TR tanks have been around decades so did pre Ethanol steel petrol tanks have less of a rust issue? I know almost all cars now have plastic tanks so moisture in ethanol is not a rust issue. I’d considered ally but the look, stiffness issue and cost put me off a bit, but as Podone Andy says further problems will happen at the worst times so I’d prefer a long term solution. Cheers Keith Quote Link to post Share on other sites
Waldi Posted August 31, 2023 Report Share Posted August 31, 2023 Hi Keith, we are deviating from the root cause (which is fine off course) but it would be good to understand the issue first so it can be properly adressed. Pictures can be misleading, but the deposits in the filter do not look like “rust” to me. The fact that sulphuric acid does not react with them is a strong indication. More likely they entered via the petrol pump or from a failed hose (the inside layer). That could be a return hose too. Are all hoses ethanol-resistant, not only the ones from tank to filter? If there is no specification stamped on them that meets this requirement, they are likely not suitable. If it is a “hose issue”, then a new tank will not solve your problem. Waldi Quote Link to post Share on other sites
ntc Posted August 31, 2023 Report Share Posted August 31, 2023 40 minutes ago, Waldi said: Hi Keith, we are deviating from the root cause (which is fine off course) but it would be good to understand the issue first so it can be properly adressed. Pictures can be misleading, but the deposits in the filter do not look like “rust” to me. The fact that sulphuric acid does not react with them is a strong indication. More likely they entered via the petrol pump or from a failed hose (the inside layer). That could be a return hose too. Are all hoses ethanol-resistant, not only the ones from tank to filter? If there is no specification stamped on them that meets this requirement, they are likely not suitable. If it is a “hose issue”, then a new tank will not solve your problem. Waldi +1 definitely Quote Link to post Share on other sites
keith1948 Posted August 31, 2023 Report Share Posted August 31, 2023 Hi again Waldo has made a good point. Are the bits in the tank attached to the metal or just deposited. Can you suck some of them up using a bit of tube and compare them with the bits in the filter. Waldo has reminded me that with fuel injection you will have a return hose. As he says the bits could be from the inside of that hose if it is old non ethanol spec. It doesn't look like rust to me but I could be wrong. Doesn't look quite the same as the bits in the filter either for that matter. If the bits inside the tank are attached to the tank then maybe rust but if they are loose then suggests they are from elsewhere. Keith Quote Link to post Share on other sites
rcreweread Posted August 31, 2023 Report Share Posted August 31, 2023 Keith - sent you a PM this morning s we which I can see you haven’t yet read - it’s in your forum mailbox which is the envelope icon at the top of the page cheers Rich Quote Link to post Share on other sites
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