Hi there,
I read a bunch of things about the rust removal with vinegar. I did this method on a few things (gearbox, oil tank)
I did the petrol tank like this
3 days in vinegar
washed it out with stones and petrol
rinsed it out with water.

Then it started to "flash rust" inside. As im not using it I swilled oil inside to try and stop the rapid rusting.
I have looked now (2 weeks later) and the inside stinks and is full of rust again.

I do not want to use tank sealer as there are no leaks. Is there something else that is supposed to be done to stop the rapid rusting? It seems like the vinegar treatment has made it rust at an accelerated rate

email (option): hutman80@hotmail.com

Hi Maxwell

Vinegar is an acid and is corrosive.

White vinegar is recommended for cleaning oxidisation from brass but needs to be thoroughly rinsed afterwards, brown vinegar contain barley malt extract, which is sticky.

The bottom line is whatever you put in your tank to clean it has then got to be removed afterwards which isn't that easy.

Rob.

email (option): robmiller11@yahoo.co.uk

Try it with phosphoric acid (diluted!). This should convert the rust to an iron phopshate coating which is stable and hopefully prevent any further rust forming. Rinse well with water and dry (a hair drier down the filler works OK)
Cheers
Pete

email (option): petercomley@web.de

I treated a VERY rusty tank with phosphoric acid, turned the inside of the tank black and cured the problem. Magic!
Cheers, Mick.

email (option): mick@motorbikemike.org.uk

Mick
Where do you get phosphoric acid from?

email (option): gasboy@btinternet .com

I think it's available from building suppliers in the form of brick acid or patio cleaner

email (option): davmax@ntlworld.com

or coca cola (about 0.2% so not really a viable alternative)
Pete

email (option): petercomley@web.de

Coopers DIY in Bungay. I'm sure most DIY shops will sell it.
Cheers, Mick

email (option): mick@motorbikemike.org.uk

Looking on the Internet it looks like phosphoric acid can be dissolved by Ethanol.

I'm not sure if this means the crystalline structure created by the phosphoric acid and ferrous oxide in the petrol tank would be broken down by the levels of ethanol currently in fuel but its possible.

email (option): robmiller11@yahoo.co.uk

Is there anything this damn stuff doesn't dissolve?

email (option): mick@motorbikemike.org.uk

email (option): viaconsu # planet dot nl

Unfortunately I have already done it with vinegar, I think I need to put something else in to stop the effects of the vinegar.
Maybe bicarbonate of soda

email (option): hutman80@hotmail.com

I'd still go for the phosphoric acid treatment. Clean the vinegar/oil out with petrol or whatever works and if possible a last rinse with acetone will get it really clean and dry. Then use the acid which will convert any flash rust to an inert coating. You can then rinse the tank out well with water and dry it, preferably with forced hot air (that hair drier again, I new I would find a use for one after going bald).From then on you can do what you like, it should stay as it is indefinitely. Ethanol should have no effect as there is no acid left, only the iron phosphate coating.
Phosphoric acid is in quite a few "rust converter" products which can also work if you can't find a source. I'm lucky in that I can order mine concentrated direct from laboratory suppliers and then dilute it as required. Don't leave the acid in contact for too long though. I put some bolts in a jamjar full of the stuff and forgot them. A few weeks later I had a nasty goo and and some sorry looking nails

Cheers
Pete

email (option): petercomley@web.de

Yea I'll try and get some, cheers.
nice one

email (option): hutman80@hotmail.com