Rust in tank

[Dezza]

If you fill a rusty fuel tank with dilute oxalic acid, this will give you a rust free tank (if the rust is surface rust). Oxalic acid is the active ingredient in commercially available rust removers. The granules are freely available and cheap (Eblag) because dilute oxalic acid is used by apiarists (bee keepers) to disinfect their hives. I think it also kills varroa mites. Dilute citric acid also works well for rust removal, especially rust spots on chrome. Citiric acid is also cheap and freely available as it is used in cooking (1 teaspoon = the juice from 1 lemon),  is more convenient to use than vinegar because it comes in powder form, and it works better.

 

With tanks after a couple of hours, drop in a handful of steel, unplated nuts and bolts into the acid solution, replace the cap and seal the outlet for the tap, and give it a good shake. Empty, flush with clean water and dry as quickly as possible and you will be amazed at the results (in a positive way).

[Nickydodds]

I tried most of the above methods on my kat tank and while the electrolysis method works it's as slow as fuck. Ended up sacking it off in favour of white vinegar and a pull chain off a set of lifting blocks instead of nuts, bolts, or ball bearings etc. I figured the chain laid flat on the inside of the tank would be quicker due to the increased contact area.

chain slides across the inside abrading rather than rattling/bashing. Tank ended up like new.

[Roycee]

Thanks for the tip - did you seal the inside of the tank ? 

[Screwriverracing]

Any before and after pics?

Cheers SRR

[johnr]

electrolysis method works better if you use a fish tank pump or windscreen washer pump to agitate the water and keep it moving round. even a fish tank air pump will help.

[carlinmidarlin]

Ive used por15 on a few tanks now and had no bother so far

[Nickydodds]

Although the vinegar/chain method worked brilliantly it also uncovered evidence of a previous repair which it must have disturbed. Eventually it pinholed  and started bubbling the paint.

as the fairing needed painting anyway they were dropped off at Rapier in hull where the tank was re-repaired and sealed with por15. Two and a half years down the line and no problems as yet.

never thought to take before and after pics tbh.

 

Edited October 24, 2016 by Nickydodds

[melkweg]

Started adding a spoonfull of two stroke oil to last fill up of petrol if bike is going to be stored for a while after noticing two strokes don't seem to suffer as badly from gummed up carbs. Run for a few miles before storing to get mixture coating everything. Not done a side by side test. If you buy the right oil it makes it smells good as a bonus.

Edited October 24, 2016 by melkweg

[nick65]

Very nice looking Kat that.

[Dezza]

On 25/10/2016 at 7:48 AM, melkweg said:

Started adding a spoonfull of two stroke oil to last fill up of petrol if bike is going to be stored for a while after noticing two strokes don't seem to suffer as badly from gummed up carbs. Run for a few miles before storing to get mixture coating everything. Not done a side by side test. If you buy the right oil it makes it smells good as a bonus.

Yep, it seems so obvious. I have an ancient 2 stroke (1972) that someone had ditched the oil pump to run pre-mix and low-and-behold the tank has no rust at all inside. It probably wouldn't do one of these new-newfangled bikes with cats much good though to add a bit of 2 stroke oil to the fuel before storage.