cleaning out a fuel tank

[mojobaby]

I've just read an interesting post on the oldclassiccar.co.uk website.

Someone commented that he had cleaned out the rust and dirt in his fuel tank by putting in a few handfuls of small pebbles, adding water (probably hot) and shaking it around vigorously.

Has anyone tried that? It certainly beats the chemical option.

 

[Cornish4]

I've never tried this process myself, but I know of people that have cleaned out fuel tanks this way and apparently it works very well.

 

[renoir cigar]

One of our senior gurus at our local car club does this on a modified cement mixer, lets it roll around for hours, I did mine withthe POR 15 kit from the states, lots of evil chemicals but solves the problem perfectly.

 

[Dawier2]

And how do you clean the brass petrol pipe going to engine?

 

[mojobaby]

One of our senior gurus at our local car club does this on a modified cement mixer, lets it roll around for hours, I did mine withthe POR 15 kit from the states, lots of evil chemicals but solves the problem perfectly.

A brilliant suggestion Renoir Cigar, my cement mixer still looks like new inside after 10 years because I run it with pebbles and water afterwards. I could always strap the fueltank to the front of the mixer, fill it with pebbles and water and let it turn for 20-30 minutes or so.

 

[DavidN]

Funny that this topic popped up right now.
I am in the midst of cleaning and prepping a tank as well.

When I did my resto back in 2009/2010 I only drained and flushed the fuel tank of my F6 van and just painted the outside.

http://www.renault4.co.uk/forum/showthread.php?t=3173&page=5

As I left the inside of the tank untouched (what turned out to be a bad idea) I am running a 2-filter-setup since the van got back on the street.
(In addition to the regular fuel filter in front of the carburettor I fitted a second inline filter right in front of the fuel pump.)

After 3 Years I still have to regularily change both filters as they fill up with nasty, grainy, brownish residue.
This stuff is so microscopic that it partially makes it's way through both filters and ends up in the carb as well. (See pictures below.)


To prevent that in the future I bought a used tank and will prepare that one thoroughly.

First step was to drain the tank and to clean it from the outside.

Then I removed the sending unit and flushed the tank with fresh petrol.
To remove any residue I added a handful of clean screws and nuts to the fuel in the tank and gave it a good shake.
You won't believe how filthy the mixture was when emptied out of the tank. :eek:

After that I flushed the tank with some thinners to clean it from any dirt and grease left inside.

Now I fought the rust inside. :evil:
I filled the tank again with a handful of clean screws and gave it a very good shake.
(See picture below of the screws and what came out the tank.)

I repeated that step a few times. Here a cement mixer would have come in very handy!

The last picture shows the clean and mostly rust free inside of the tank.

Next steps are ...
- Cleaning of the inside with some heavy duty dissolvent
- Fighting rust the chemical way (oxalic acid?)
- Converting rust inside (phosphoric acid)
- Sealing inside against rust (Kreem / Por15 / Tapox (Fertan) - I'm still undecided which product to use)

Cheers,

David

 

[pepper]

Ive used por15, on my old Morris Oxford and it worked brilliantly!

I used the cleaner first with gravel to clean the tank out then blocked all the outlets etc and filled it with the special paint. Its never leaked or caused me any problems since.

 

[orsome]

fuel tank debris

Ive used por15, on my old Morris Oxford and it worked brilliantly!

Take a look what i wrote under thread "Zenith IF problems" my problems and solution for "idle jet jamming"

 

[DavidN]

Take a look what i wrote under thread "Zenith IF problems" my problems and solution for "idle jet jamming"

Problem here is that the alcohol could have very well eliminated the water in your fuel, but the rust and so the grainy bits that end up in the filter and eventually in the carb are staying in your tank.

For more than three Years now I changed fuel filters every month or so and tried to close my eyes regarding that specific problem.
But in the end you'll end up with either buying a new tank or restoring what you have.

And I seriously doubt that there is one single rust-free tank out there unless it's a new or a restored one.
That mainly has to do with the change in mixture of the petrol itself when in 1988 the lead free fuel has been introduced.
Our old tanks are simply not made for that stuff.

 

[petak]

Nice work DavidN.

I still need to go that road, but was thinking about it.
My concerne is what kind of "paint" put inside tank that wont be dissolved by petrol

 

[allez-y]

After thorough cleaning, the only tip I can share here from one local craftsman is to keep the tank fully filled when you don't drive for a long time, for example in winter period. Not half, not empty! Also, he doesn't recommend to paint inside. Sooner or later all the paints weaken over time.

 

[DavidN]

After thorough cleaning, the only tip I can share here from one local craftsman is to keep the tank fully filled when you don't drive for a long time, for example in winter period. Not half, not empty! Also, he doesn't recommend to paint inside. Sooner or later all the paints weaken over time.

The problem is that modern fuels with their additives adhere water.
So a tank without some kind of inside surface protection will get rusty sooner or later.

What your local craftsman said about paints weaken by fuel is only true for the one compound type of paint. The one that dries by solvent evaporation.
The modern 2 pack (2K) paints do not dry. They cure by a chemical reaction and therefore should withstand chemicals like petrol and petrol additives without any problem.
That is why I am so hesitant to use a product like POR15 to treat the inside of my tank. It is a one compound type of paint whereas the other products like KREEM or TAPOX (by Fertan) are coming with a base resin and a hardener.

 

[renoir cigar]

I don't work for them but a POR15 kit with cleaner prep and seal is about $150 australian, so probably 90 pounds? You tape up the gauge hole , add the tank cleaner and hot water, add your gravel, tape up filler hole and give it recommended time, then use metal prep chemcal, (resusable) then pour in seal paint, roll it around till all covered, there's a litre I think and you know it gets everywhere in there with that volume and then pour out remainder. They say it isn't reusable but if you do it quickly enough you can pour it back into tin and use for another job.
Easy.
problem solved.

 

[renoir cigar]

I missed that David, I think these guys are selling this product with a big degree of confidence so I am not in the least worried about it crapping out in the near future, in fact I reckon it's as tough as anything if not tougher, all I know is it's a really evil stuff!

 

[angel]

Some years ago I treated a Volvo 544 fuel tank, which had been standing for 20 years in a field, with the POR15 product. I followed all the steps exactly, including drying times etc. The result was amazing, to say the least. Abloutely no traces of dirt/rust in the fuel filter, even after some 4000 kms of driving.

That said, make sure you follow the instructions meticulously, and use only fresh product. I used the same POR15 paint that had stood for some time on my shelf, in a Lancia Fulvia tank, and although initial results were promising, it never hardened fully, and after some time it clogged the fuel pickup tube.