Rust in petrol tank

If it's light rust and no leaks I would avoid sealing the tank - too many tales of sealant failures with current petrol. As for removing rust, a handful of steel balls (these old main bearings have their uses) and paraffin and a prolonged shake should do what's required. You might consider a fuel line filter BUT be careful you fit one which is ethenol resistant. I have heard tales of these things failing and spraying petrol on hot exhausts.

Buy 500g of critic acid powder, pour into the empty tank and then fill with warm water and leave for a day or two, rinse it out with water and the store in a warm place for it to dry out. The Citric acid does not attack the paint or good steel. Doing a tank using that very method now, one leak appeared which can be seen from the cap and is where the rust has been eaten, the tank had bee sat for 20 years unused and had rusted internally, it is now completely clear of rust and off for welding the hole shut next wednesday before a repaint. Sealing is best left alone, too many tales of ethanol dissolving the linings, it happened to me twice and its a pain getting the pieces out through the filler neck. Another alternative is phosphoroic acid which converts the iron oxide to iron phosphate which acts as an anti rust coating.

I'm pleased to hear warnings of the Ethanol threat and the best policy is not to use petrol with the stuff in. Not always easy as our politicians have made it difficult to know what you are buying with regards to petrol but I have found that BP Ultimate outside of South West England is sound.

The best method I know of cleaning the inside of a rusty tank is to put a couple of handfuls of clean pebbles or nuts and bolts etc into the tank, seal it up and put it inside a concrete / cement mixer, securely cushioned of course. 10-15 minutes going round usually does the trick and all will be shinyinside.

I like this idea - never tried it as yet - but looks like a good method..

https://www.youtube.com/watch?v=cTKHZSKuJtQ

Regards - Paul.

I recommend the phosphoric acid method. As John said, it leaves an anti-rust coating afterwards. There are proprietory versions available, for example Hammerite do one. You buy a litre and dissolve it 10:1 in warm water, as warmer means quicker acting. I use a large plastic storage bin, place the tank in it, and fill to the brim. Don't worry if some leaks out in contact with the exterior of the tank. It is totally harmless to paint, chrome etc. You can then store the solution in plastic containers, where it will keep indefinitely for re-use.

One thing I would say is that, whichever method you use, dry it out immediately, as leaving it for a couple of days to dry naturally will simply allow it to coat itself in rust again, particularly if you don't use phosphoric acid. An airline and a hair dryer and a bit of patience; something I'm not renowned for, ahem; does the trick.

Previously paul_smith wrote:

I like this idea - never tried it as yet - but looks like a good method..

https://www.youtube.com/watch?v=cTKHZSKuJtQ

Regards - Paul.

Interesting that he mentioned rinsing it with Coca Cola; it contains phosphoric acid

.....which is why it cleans up old coins like new!

I have used quartzgravel and phosphoric acid, shaking for several minutes to get the loose rust off inside oil and petrol tanks, though this doesn't reach the corners.Then,I do the final clean up with the electrolysis method, but I put theanode attached to a suitable length of heavy cableinside a piece of 1/2" X 2 - 3" long plastic conduit full of 1/4"drilledholes. This insulates theanode from touching the inside of tank andshorting out, blowing the fuse. This way, I can poke itdown into the hard to reach sides and crevices, as mentioned in the video. I did an oil tank recently which took 2 days, using a 4amp charger attached to a 12V carbattery.This method releases plenty of hydrogen from the water, and will be seen soon bubbling up when the power is on. When the tank is clean, quicklydry withhot air(hair dryer or your local politician)and spray with some oil to seal the surfaceto stop it from flashing over with surfacerust, which will happen very quickly. I also have cleaned up old spanners etc this way. It also strips out any hard, oily sludge in the bottom of an oil tank.

There are several articles on this methodto befound in 'Google'

Wyldes new flowliner is ethanol proof and is good stuff. It goes on really well. I use BP ultime, E0 in most places but you never know when things change to meet political renewable energy targets.

Old Bike Mart doing a big write up on the Ethanol scandal, about time the media got serious and stopped licking the Green Blob's butt by minimal commenting. Good luck with the tank and stay clear of EN228.

Wyldes new flowliner is ethanol proof and is good stuff. It goes on really well. I use BP ultime, E0 in most places but you never know when things change to meet political renewable energy targets.

Old Bike Mart doing a big write up on the Ethanol scandal, about time the media got serious and stopped licking the Green Blob's butt by minimal commenting. Good luck with the tank and stay clear of EN228.

Hi Chris, I am sure you are going the right way, with the phosphoric acid treatment. Rattling foreign objects, in the tank, will never remove all the surface rust (and maybe cause a leak where there was none before). A wire brush, in an electric drill, struggles to remove all surface rust on external metal, rattling pebbles, or ball bearings, on the surface would take a lifetime. Regarding sealing, if it doesn't leak, don't seal it! Regardless of ethanol, who knows what other fuel additives may be introduced in the future.

John, I would hope that the piece of mind I gave to the FBHVC will ensure that the composition of petrol will never have another unwelcome agent added without forewarning.

Previously Neil Wyatt wrote:

John, I would hope that the piece of mind I gave to the FBHVC will ensure that the composition of petrol will never have another unwelcome agent added without forewarning.

Neil, Do you believe in Father Christmas as well? Since when has public opinion stopped businesses, or politicians, making a quick buck?

Jonh, Father Christmas not involved in this one but he can gift me some E0 fuel when he passes this way.

This is about meeting renewable energy targets and being fined by the EU for not meeting them, rather than making a fast buck! The Green Blob!