Rust in tank

[almostthere]

Just noticed that the filler cap on my wn is letting water into the tank and there is a patch of rust around the petcock the rest of the tank is pretty clean should I just ignore it?  what effect would it have

[Sheep]

If its very light i shouldn't worry too much but if its worse then you may want to empty it out and take a closer look.I its that bad then there are products out there that will seal the tank making it good again.

A wise man once told me during winter/storage months keep the tank full to the brim of fuel,even with a dash of oil in it,until you put it back on the road again.This will stop water/condensation taking a hold on the walls of the tank.Come spring time,empty the fuel into the lawnmower and re-fill......either that or take the tank off,empty it and store it somewhere dry,like the wife's wardrobe

[Swirl]

good call Sheep, I have also heard of a bag inserted into the tank ethanol resistant blown up to fit the tank, never seen it , could be worth a look

[Captain Chaos]

petrol nowadays contains ethanol, which absorbs water. Not good in fuel tanks.

So it's probably better to empty it and store it warm and dry, maybe squirt some WD40 in it

[Sheep]

I did not know that.....every day is a school day

[Pheasantplucker]

I like the empty tank and wd40 method myself

[johnr]

ok, first off you need to find out why your filler is letting water in the tank, if its a recessed filler, then when you take the cap off, you will see a small hole in the bottom of the recess that is designed to let rainwater drain away, they easily get blocked with crud, dirt, bits of leaves, twigs etc, so either blow it out with a compressed ait line or else use a thin wire down it to poke it clear.
next you MUST drain the tank. the petrol outlet isnt at the bottom of the tank, its slightly above it, and as water sits at the lowest point, the water you get in there will sit below the fuel take off and slowly rust away your tank from the inside. if left, it will certainly rust it through. whilst it eats the tank away, the small bits of rust that are as fine as dust will get through the system and into your carbs, clogging stuff up nicely, and dont think that you can fit a filter, the particles are fine enough to pass through any in line fuel filter you might fit. so tank off, drain fuel, take tap off, empty and dry tank then you can assess whether you just put it back on, remove the rust, or even seal the inside of the tank. this depends on how bad the corrosion is. you can buy a small probe with a small inspection camera on the end that will plug into a smartphone, you can use this to inspect inside a tank. if you find a lot of rust, youve a number of options to get rid of it. you can buy kits like por15 that will allow you to degrease, derust and then seal the tank to prevent further corrosion.  or you can remove rust by electrolysis, (google electrolytic rust removal, you will need an old battery charger, a nail, some copper wire and some washing soda) its simple and very effective. but if you leave it as it is, it will rot away and give you a load of grief to sort it.
but fwiw, dont use petseal!!

[coombehouse]

On 4/1/2016 at 8:13 PM, Captain Chaos said:

petrol nowadays contains ethanol, which absorbs water. Not good in fuel tanks.

So it's probably better to empty it and store it warm and dry, maybe squirt some WD40 in it

Been led to believe that super unleaded contains little or no ethanol in it yet. Fill the tank with this stuff along with some fuel preserver (Gurls blouse stuff is good) & the fuel will be ok for at least a year. Been doing this 20 years so it does work though fuel has got worse in recent years.

For rust removal the electrolysis works perfectly (info on Google) but can take a week if its bad & modern battery chargers wont work. A car battery hooked to a PC power supply is a cheap option. 

The bag in the fuel option to absorb water is something I saw a few weeks ago. Its distributed in EU by Rochford Garden Machinery in Wincanton, Somerset. They also do fuel saver & a trick water trapping fluid. Apparently fuel & water is a huge problem in the horticultural world.

[Swirl]

some good info and very comprehensive posts, I have heard that the shell v power has no ethanol, this all I use in my bikes, electrolysis is the way forward as stated, I would not bother lining the tank

[busa ash]

the best fuel too use is super unleaded as stated above it doesnt have ethanol in , i have been saying for the last few years any carb bikes need to be run on super unleaded as it doesnt gum up the carbs ,  the normal unleaded fuel breaks down in 4-6 weeks so if your not using your carb equiped bike problems will occur

 

[Rossco(Iceman Josros)]

Ash when the fuel breaks down what are you left with ??

[coombehouse]

On 4/16/2016 at 5:31 PM, Rossco(Iceman Josros) said:

Ash when the fuel breaks down what are you left with ??

Looks & smells like sticky brown varnish. Sort of stuff you would paint a garden bench with. You cant get the smell off your hands either.

[Captain Chaos]

6 hours ago, coombehouse said:

 You cant get the smell off your hands either.

you can, just wash them in really old fork oil.

[kenty]

mix a gallon of fuel with a couple of pints of water , leave it to settle out , drain the water off and magic will happen ....... you get more than two pints of water ,because it draws the ethanol out of the fuel ... result , unleaded without ethanol . classic car guys do it .

 

[Captain Chaos]

8 hours ago, kenty said:

mix a gallon of fuel with a couple of pints of water , leave it to settle out , drain the water off and magic will happen ....... you get more than two pints of water ,because it draws the ethanol out of the fuel ... result , unleaded without ethanol . classic car guys do it .

 

That's good to know.

[Swirl]

interesting can see the logic

[rustychain]

put some magnets in the tank if its not to bad .. worked for me 

[Reinhoud]

Electrolysis is the best way to get rust out of a tank, takes quite long, but works absolutely perfect!

[Del]

18 hours ago, rustychain said:

put some magnets in the tank if its not to bad .. worked for me 

As above,break up a speaker magnet and slide it in around the hole were the fuel tap goes,no more rust in the tap or carbs

Cheap rust remover from the tank,is the cheapest nastiest coke that you can buy(Happy shopper and tesco 17p value coke works really well),5 litres will do,swill around and leave to stand for 3 days. Empty out and leave in a dry,warm place(airing cupboard).Then swill out with clean fuel. Did my brothers tls tank and fuel pump holder,now they are  clean and rust free

Edited July 28, 2016 by Del

[rustychain]

hard to  believe it works but it does .. 

[Leblowski]

Electrolysis is the way to go did a few tanks so far

It's magic!

[bernardo]

Soap works quite well on pinholes, reacts with the petrol to form a hard substance. Also hammerite rust dip is quite good

[crashtester]

On 7/28/2016 at 10:43 PM, Del said:

Cheap rust remover from the tank,is the cheapest nastiest coke that you can buy(Happy shopper and tesco 17p value coke works really well),5 litres will do,swill around and leave to stand for 3 days. Empty out and leave in a dry,warm place(airing cupboard).Then swill out with clean fuel. Did my brothers tls tank and fuel pump holder,now they are  clean and rust free

Thanks for that tip. Going to give that a go now. 

[Captain Chaos]

vinegar also works well to remove rust

[johnr]

electrolytic rust removl is speeded up incredibly if you use a small pump like a washer motor pump or a fish tank pump inside the tank to keep the electrolyte moving all the time.