Fuel tank lining clogging line and carby

[Rick K]

My Haflinger 700AP bug-eye runs beautifully, except recently when the fuel filter began fouling and eventually the motor began to be starved of fuel. The original lining of the fuel tank has been lifting away since I let the tank run dry. I have removed the tank for reconditioning, and found the fuel line banjo to be completely chocked with crud. I cant believe any fuel got through at all. See photo of the amount of crud that one wee banjo can hold.

The tank is being chemically stripped by Redi-Strip, to the point where it is raw steel. I will then re-line with POR15 fuel tank liner, which I have found to be terrific product- as long as you follow the instructions to the letter.

with regards from Sydney

Rick

[heinkeljb]

Typical of the older petrol tank sealants - new fuel has a higher percentage of ethanol in it and so eats the older types of tank sealants.

New tank sealant should be more resistant to the effects of the increased ethanol.

Hopefully the people who are cleaning your tank will repair any holes they fins properly so you are not relying on the sealant to provide a 100% seal.

Have you got access to an air compressor? You really need to clean the rest of teh fuel line as well if you got that amount of crud out of the banjo! Failing access to an air line, a suitable length of household mains electrical wire should fit and be flexible enough to be manipulated down the fuel pipe to clear it. Or if you have a suitable length of bowden cable - the inner cable of the sort used for the handbrake cable, that you can run down the tube.

I have to do a similar thing to Lurch's fuel line at some point - also has old style petrol tank sealant in it.

John

[Bigdougal]

I have just bought a new fuel tank from Haflinger Technic. It was not sealed internally. I asked Dale what I should use and his response was it isn't necessary. Discuss!

[heinkeljb]

A brand new tank which does not have any rust in it and no holes in the seams does not need internal sealant to keep the petrol in! The problem is the fuel has an anti rust additive in it, so only if the fuel tank is always kept full will it prevent rusting...

At the very least the inside of the tank should be painted, but what paint is petrol resistant?

If your tank is zinc plated then just paint the outside.

John

[Techmogogy]

Does not need to be full of your using it.
Its a small tank and even 1/4 full the fuel will slosh and splash all over the inside of the tank as you drive and hit bumps, rocks, go over curbs etc
If it sits for weeks or months then coat/seal it

[Vampyr]

I have just had an aluminium copy made, would that need an internal coat as well? Wouldn't think so but interested in opinions, regards Danny.

[heinkeljb]

Hi Danny,

I think it would depend one the type of aluminium used to make it. Some aluminium (more pure?) corrodes when exposed to the weather - horrible white salt type stuff, which obviously wouldn't be good in a fuel line. Most Aluminium that is used is an alloy of some sort, but even that corrodes which is why most is lacquered.

I would coat it even if only for piece of mind.

I agree that even a small amount of fuel in the tank will splash and coat it, but as i have no idea how long it would take for it to evaporate / run off the sides, top etc. There is no way of knowing how long you could leave it before any protection provided by the fuel is gone and rust has started!

Like the aluminium tank above, I would coat it as then it would be more of a fit and forget item rather than one you would constantly have to monitor.

If you are going to coat the inside of the petrol tank make sure you BUNG up the petrol pick up pipe entrance hole before putting sealant in - would be a real pain in the backside to have to try and unblock it after the sealant had gone off!

John

[Bigdougal]

On the subject of fuel tanks, does anyone have a dipstick for a late model fuel tank ( under front seat). If someone has one could they let me know the volume markings so that I could make one.

[heinkeljb]

Put a fuel gauge in!

Or:-

Empty tank via drain plug.

Pour .5 litre of petrol in, put stick in and remove. Measure how high the tide mark is.
Pour another .5 litre of petrol in, put stick in and remove. Measure how high the tide mark is.

Continue until tank is full!

Then you have all the required measurements to be able to transcribe on to a dip stick of your choice...

John

[Bigdougal]

Cheers John,

Well explained. Just like I have done it on a myriad of occasions. I was just wondering if anyone had one so as to save me all the hassle.

[AustHaflinger]

A new tank made of any of the usual materials will not need a liner. (though some tanks installed in brand new vehicles have a plastic liner similar to the plastic liner used in food cans).

The fuel used is enough to normally provide protection and a varnish from the fuel will often form to provide extra protection. The issue comes when water gets into a steel tank (even if there is fuel in it) and the tank sits where the water can start to corrode the metal - will be much faster if there is no fuel in it. Likewise an empty tank may also corrode in a wet/damp environment.

It is primarily after these conditions that a liner may be needed to seal the damage and to also prevent it happening.

I had a bike tank that was rusted and the POR 15 liner worked a treat even filling small holes - in the other hand I have had a jag tank out of the car for 10 years and has been dry stored and there is no evidence of surface rust on it at all and will not need lining - I guess the old varnish lining it from the old fuel is still protecting it - though I did make sure it was completely empty before storing it.

Some of the old landrovers I have are weeping at the seams of their tanks which are soldered together so I will line these to seal the seams.

Garry

[Rick K]

I picked up my newly stripped fuel tank yesterday, and have already painted the outside with POR15 rust preventive paint. Ill go through the long process of treating the interior of the tank prior to applying the sealant tomorrow- you have to work quickly as corrosion commences almost immediately once outside of the chemical bath.

[Yakov]

On this topic, does anyone have any advice for chemically stripping the tank of the old liner? I'm having trouble with it. Is Redi-strip a product or a service? And does the Por15 brand, Por-Strip work? What did you guys use?

I tried a dichloromethane based stripper from the hardware store and it took the paint off the outside of the tank, but not so much on the inside.

[SAM]

Hi Yakov

I have done 3 Pinzgauer tanks now and these are even more difficult as they have the baffles inside which are a B*****d to work around. Try a chemical stripping firm like Rick has, there are bound to be a few about where you are.

Alternatively I had great results from a company here that did thermal stripping. It was mostly for the powder coating industry for stripping the build up on the production lines. It uses a Huge gas fired oven the heats up to 400 degrees for 4 hours or so and turns everything (grease, paint) to ash which just needs a pressure wash off afterwards. Extremely cheap too!

Warp is not an issue either as the Haflinger panels are thick enough for this not to be an issue. Ask powder coaters locally to see if they know of anyone that has a setup. I ended up using it for loads of parts it was bloody brilliant! The oven was so big the bloke there said he would put an entire Haflinger platform in if I wanted! It is no good for ally though but they used to use it for rubber too.

Then just reline as Rick suggested. I used KBS products and I have been happy with them but POR15 are top quality.

Good luck

Sam

[Yakov]

I guess I just have to fork over the money and get someone to do it professionally. The Haflinger tanks I've seen have baffles too, so its hard to see what effect anything has on the hidden sides. I really don't like breathing the chemicals while I'm trying to rotate the tank to coat all the sides...

A radiator place I phone told me they would cut it open, sandbland and weld it back up, but that seems crude, no?

[SAM]

I did 2 Pinzgauer tanks that way and it works out more expensive in the end. My welding is ok but not good enough so that cost. Also the problem is the fuel seeps into the metal over the years and can make it dodgy to weld. Interestingly the heat process gets rid of all that fuel too. Seriously go for chemical stripping or heat. Either of these processes should not be too expensive and like Rick said you have a blank canvas not a compromised tank. With the welds I was always a bit wary of it being a bit weak if it got a ding and split open.

Sam

[kerry460]

i usually found the biggest rust problem was rust under the extra panel on the front of the tank .
i had Rheem coat the inside of mine with the same epoxy they used in there avgas 200 litre drums

kerry

[Rick K]

I have finished off the fuel tank reconditioning. For the POR15 process, first I rinsed with Marine Clean to remove any traces of oils and fuel gum residue. I think this is essentially sodium hydroxide. It needs to be rinsed well with water before treating with Metal Ready. The Metal Ready acidifies the surface to allow the POR15 liner the stick optimally. It is critical for the tank to be perfectly dry before pouring in the POR15 liner. This is done with a heat gun set at a low temp- just stick the neck of the gun into the fuel filler hole. It takes about 2 hours to become bone dry.

I used sections of disposable nitrile glove and wadding to seal the tank. The POR15 is then poured in, and tank rotated to get into every corner of the tank. Coating the internal baffles can be tricky, so you have to 'imagine' the flow of the paint. You have about 20 minutes to work the paint around. Leave the tank upside down so that the paint accumulates in the thickest layer on the ceiling of the tank rather than the floor. Little liner 'stalagtites' form on the floor of the tank, but that's no big deal. The liner cures in a day or two.

[Rick K]

As Kerry mentioned, the main problems with rust arise from the welded plate on the tank just behind where the wheel sits. Here moisture accumulates and is the main site for tank corrosion. With my tank, there were already some pin holes evident, but thankfully the integrity of the tank was not compromised. To extend the life of the tank, I injected SW2 rust preventative oil (also made by POR15) into the vent channels. Hopefully that will do the job for another few decades. The Haflinger now runs and idles beautifully. Wish I did this years ago...

[AustHaflinger]

Hi Rick - the POR15 tank sealer/liner is good stuff - even fills small holes -as you have indicated need to be kept mobile until it goes off.

For blind spots that rust can develop - like the tank and the double thickness area that strengthens the steering box/pedals I use Penetrol http://www.floodaustralia.net/products/ ... i_rust.php = can be mixed with paint to provide additional protection. I also squirt it in the front stiffening panels under the front seats.

Thanks for the pics - I now need to look at the hidden bits on my tank.

Cheers

Garry