Cleaning fuel tank

[asj1]

At the end of the season the fuel filter was extremely dirty - I had deliberately run the fuel low though. I decided that I needed to drain the fuel from the tank and try and clean it in some way.

Needless to say the drain plug on the tank wouldn't budge - access was very awkward with the tank in place.
I have now removed the tank - itself requiring removal of the water tank first- and taken it home. There I have managed to get the drain plug out and drained out the remaining dirty fuel.

I have then refilled with a gallon or so of diesel swilled it round as best I could and emptied it, filtered the fuel and refilled and repeated a few times. This has done a lot of good but the fuel is still not coming out perfectly clean. So the question is - am I ever going to be able to get the inside of the tank sufficiently clean in this way ? Has the fuel got to be absolutely clean ( I have a secondary and a primary filter)?

How else could I clean it? I could partially fill with Hot water or even put a hose in - but srely this isn't a good idea as the inside of the tank will then have some water in it (it is made of ordinary steel) and some drope are bound to be left in /

What does the panel think?

Also follow up question - what sort of washer should be on the drain plug - plain copper or fibre. The plug appears to be brass. The tank is original 23 year old but in good condition - at least on the outside !

Thanks for your help .

 

[savageseadog]

Steam clean it if you can. There will be water in there soon enough anyway. The other option after steam cleaning is to use some alcohol ie meths as it is miscable with water., there won't be a drop of water if you give it a little time but it really isn't necessary.

 

[duncanmack]

Andrew,

As you have the tank out it is quite straightforward.

To get the rusty deposits off the inside of the tank (and the cruddy deposits off the bottom) get about 12 to 18 about 1/2 inch nuts threaded on a good bit of string and tie a good knot in it.

Rattle and roll the tank about so's the nuts get dislodging any crap inside. When you have had enough then catch the string with a bit of wire - welding wire or an old coat-hanger.
If you can borrow a vacuum cleaner, bodge a longer tube on to the existing hose and suck the loose crud out.

There is no reason why you couldn't use a high pressure washer to get as much rubbish blasted off the inside of the tank - a lance car-wash with TFR does fine. Keep emptying the tank and hosing like mad.

Do not worry about water droplets in the tank, cos when you finish the water treatment you then heat the tank - with a gaz stove if you want! and the water boils off. NO you won't blow it up!
Copper washer is best for the plug.

Heating the tank gets "interesting" when it has had petrol in it. Even if you go through the recommended cleaning routine it is still liable to go bang. Seen it.
Derv is OK tho.

 

[toad]

Agree with DuncanMack, put it on the BBQ or use a hot air gun. The idea is to dry it out before rust starts forming.

 

[ms1]

worth taking advice above and spending some time on it. Dont forget tanks have baffles which can trap the crud so if you can get high pressure lance right inside through drain plug and fuel gauge sender hole it will help

 

[abbott013]

Used to use small whole stones to remove rust from the inside of motorcycle tanks, put plenty of stone in with a gallon of fuel, and shake vigorously, repeat with the same stone and fuel (washed and filtered ) until clean.
Its worth saying that if your tank is rusted inside, you might want to check the gauge of the tank.
It could be time for a new stainless tank

 

[duncanmack]

Bananaman,

I use that and/or nuts for m/c tanks - they are easy to get out. On boat tanks the stones are a right B to get out hence the nuts on astring!!

 

[rogerthebodger]

Affter you clean out the diesel and loose muck
take your tank to a local galvanizer and ask hin to put it into his de rust acis bath to remove all the rust inside and out. Then quickly paint the outside only.

Replace the plug with a stainless BSP Taper and seal with PTFE tape.

 

[dolphin]

if the tank is the steel one, i would suggest to change with new, for avoiding later repeating the same procedure !
you can expect to have a corrosion in a low part of the tank
after 23 years in service !
i am doing the same thing right now !

 

[asj1]

I have wondered about replacing the tank. It would obviously need to be built to order to fit and with the right fittings to marry up to the fuel lines in the right places etc.
Any idea where I could get one from and what sort of prices for a very regular shape 90litres tank ?

 

[dolphin]

http://www.google.com/search?hl=en&q=boat+tanks

here are a loat of web pages with tanks of diffirend type

i will replace my tank with regular steel drum of 200 l
as the others are very expensive