Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > General Motorcycles only > Plastic petrol tank expansion problem

[jerryz]

below is a link to an excellent article about plastic tank deformation by Gasohol and includes lists of makes and models ,
not just Ducati but also HD,KTM ,Motoguzzi,Apprillia and more reports are now coming in from Europe even some BMW s have been affected.

triumph have stopped using plastic tanks and HD will be switching to steel tanks on 2012 model sporster 1200 sport
the main issue is PA 6 poly propelyne plastic and the primary manufacturer is Acerbis

www.deformedfueltanks.com
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MONSTERMAN

[skidlids]

Originally Posted by jerryz

below is a link to an excellent article about plastic tank deformation by Gasohol and includes lists of makes and models ,

www.deformedfueltanks.com
__________________
MONSTERMAN

Think I'll see if I can get my brother-in-law to have a read, he was a top researcher/analyst/trouble shooter for BP plastics division before they sold the division and still does the same job now just for the new owners

[ducatiz]

The problem has been well sussed.

PA6 - the material that the tanks are made from -- absorbs water.

That's pretty much it.

There is no inner liner of the tank, so it is in direct contact with the fuel. Gasoline often has water and sitting atop the engine means the heat creates a nice environment for condensate when it's cooling down.

Add ethanol to your fuel and you learn that it absorbs ambient humidity 10-20x faster than pure gasoline and holds more (E10 holds up to 1% water by volume, whereas pure gasoline only holds about 0.2% water by volume).

Coating the tanks absolutely works and there are many different epoxy based preparations that have been around for a long time. PA6 (aka "Nylon 6" or "polyamide 6") was invented in 1938 so its properties are well known.

[ducatiz]

Originally Posted by jerryz

below is a link to an excellent article about plastic tank
the main issue is PA 6 poly propelyne plastic and the primary manufacturer is Acerbis

www.deformedfueltanks.com
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MONSTERMAN

not poly propylene, it is nylon. Polyamide (PA) is different from polypropylene (PP).

PP will dissolve in gasoline.

PA is impervious to gasoline (and alcohol) but absorbs water.

[Steve E]

I've contacted some of the main UK fuel providers; BP, Shell, Exxon (Mobil and Esso) and Valero (Texaco) for clarification on what's in our fuel.

I have had a first response back from Valero which I have pasted below. Based on this feedback I will be filling my Sport Classic up with Texaco Super Unleaded this afternoon!

I believe E10 is being fazed in 2013 but E5 is supposed to be available in the UK until 2015 from what I've heard. But I do remember LRP disappeared pretty quickly from UK forecourts. E5 can certainly damage a plastic tank now. E10 can potentially damage carbs if left in in the float bowls and cause seals to fail

I will post any further info as soon as I receive it from the petrol companies. I am going to get my tank lined with Caswells tank liner. There are a number of companies who will do this for you listed on the Caswells UK website.

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Thank you for your email dated 14th January 2012 regarding ethanol in fuels.

Ethanol was introduced in the UK in order to meet the RTFO (Renewable Transport Fuels Obligation). In order to meet the obligation biodiesel is blended with diesel and ethanol is blended with petrol. The conversion of the specification for EN228 to include up to 10% Ethanol is currently being reviewed and agreement is not expected until late 2012. Therefore it is unlikely that gasoline with greater concentrations than 5% ethanol will be introduced before this time.

For any petrol containing up to 5% ethanol no additional labelling is required at the pump. If the ethanol content of the petrol is above 5% then there must be clear labelling on the pump stating this (for example E10).

Currently in the UK Texaco Unleaded 95 octane may contain up to 5% ethanol. Texaco Super Unleaded and Supreme Unleaded do not contain ethanol but this may change in the future.

The expectation is that E10 will come onto the UK market late 2012 / early 2013. It is advisable to speak to your car manufacturer if possible if you have any questions regarding the compatibility of your vehicle with ethanol blended petrol.

I hope you will find the information provided useful.

Yours sincerely

UK & Ireland Customer Care Team

[funkatronic]

i have an s2r 800 2006 an have started to notice some deformation as the rubber spacers no longer fit snug over the frame (in any position).

Rac3r on UKMOC managed to get a free replacement out of Ducati as a 'goodwill gesture' but they would not admit its a problem in the uk yet and claimed that his was the first one they had heard about (which is BS for sure):

http://www.ukmonster.co.uk/monster/s...highlight=tank

[Steve E]

Hi funkatronic, do you know if Rac3r's Monster was within warranty? It would be good to know if Ducati UK would entertain replacing a tank on a bike out of warranty.

I expect the problem is now well sorted on the newer models but Monsters and Sport Classics for 05 - 09 models its worrying, considering what's happened in the US.

[funkatronic]

nope his was 2005 bike and he was 4th owner i believe

dont think it is sorted, there are stories of 2010 bikes in the us starting to show signs of deformation looking th the forums

[ducatiz]

It will be interesting to see how it's handled in UK and the rest of Europe.

The lawsuit was just finalized here (rather, the settlement) and the result is that Ducati will be "modifying" bikes to allow for the deformation rather than replacing tanks with something that prevents it. This means new mounts, shorter seats and in some cases, a smaller tank so it can expand without hitting anything.

The details of the settlement are here: http://www.girardgibbs.com/ducati-class-notice.pdf

Please note that this settlement affects US owners ONLY, no one else.

Despite my and others' efforts, we were unable to get Ducati to implement some sort of barrier coating as a solution. Here in the US there are epoxy-based coatings available which are designed for use with polyamide plastics such as PA6/Nylon6 and are impervious to fuel or water. Acerbis did some testing on one of them and found it delaminated during testing, but no indication was made of how the tank was prepped or how the solution was prepped. There are literally 100s of people now with coated tanks in the US, some with 2+ years of use and showing no problems.

One thing to note: if you're experiencing tank deformation, you should fully drain your tank, wash it out with a cleanser appropriate for fuel and plastic, and let it sit in a dry place for a few months. It will return to its original shape. When storing your bike, do not leave the tank FULL as you used to with your metal tanks, you should drain it.

The problem is water -- ethanol attracts water and then the combined stuff sinks in the fuel and puts it into contact with the fuel cel wall. Nylon6 absorbs water aggressively to up to 10% by volume.

Here is one company in the US that makes epoxies for polyamides (nylons). I am sure you can find something similar in old Blighty.
http://www.reltekllc.com/adhesives-for-nylon.html

The main issue is getting coverage. We mixed the epoxy with xylene to reduce it. Xylene is compatible with nylons and with adequate air supply, it just evaporates and doesn't affect the epoxy except to thin it during application. Two coats and you're done forever.

If you coat a tank that's had petrol in it without properly prepping -- completely rinsing out the fuel and drying it -- then it will not adhere properly. There are many water-based solvents on the market which are compatible with nylon and will handle the fuel.