Plastic Tank problems: Discussion thread, see info thread sticky for updates

[mjk778]

The finish on my replacement S2R1000 tank is fine, but the cutout on the strip is not centered around the fuel filler as well as the stock one.  

-Jeff

Mine is the same. 

[BoDiddley]

It has been 2 months since my S2R 1K tank was replaced, and there is no sign of swelling. No Caswell treatment was applied.

By the way, the new tank looks great as far as finish is concerned.

Just curious, why would you not but a coating on the inside if you no it is going to swell?

[Desert Dust]

^^^^^^
The dealer in San Diego told me that he had not had any problems with the replacement tanks.

[DRKWNG]

^^^^^^
The dealer in San Diego told me that he had not had any problems with the replacement tanks.

Then his replacement tanks are either sitting on his shelves, or he lied.

[ducatiz]

Then his replacement tanks are either sitting on his shelves, or he lied.

Not necessarily.  The problem with anecdotal information is that it is not verifiable.

Moreover, gas formulations vary even during the year, so his replacement tanks may have been lucky.  If the percent by volume of ethanol locally has been lower for whatever reason, then the expansion problem will show up slower.  Also, did he coat the tanks??

However, just because no one complained yet doesn't mean it hasn't happened.  If he can show that he followed up with every customer that got a tank replacement, then I'll buy it, otherwise "take with a grain of salt."

[J.P.]

My first tank took about 2 yrs for any deformation to show. Give it some time.

[hillbillypolack]

Seems that during part of this discussion, I read something about the tanks' ability to return to original shape.  Meaning that if the tank was drained of gas, it would naturally 'dry out' and return to its desired shape.

Of course I haven't seen in personally, but could this be true, and if so, what's the time required to 'dry it out'? 

[DRKWNG]

They can apparently return to their original shape, but according to a few big brained chemistry people, the actual alteration to the material's properties do not return; thus leaving you with a weakened (theoretical) fuel tank.

[ducatiz]

The tank wall will dry out enough to shrink but it is unlikely all of the moisture has come out.  There is no set time, but it is probably predictably long or short according to how long it took to deform.  Also, it is unknown to what extent ethanol affects the integrity of the material.  Some types of nylon are SOLUBLE in ethanol.

[Scissors]

Nylon 6,6 properties:
http://www.matweb.com/search/DataSheet.aspx?bassnum=O2500&group=General&ckck=1
Edit:  Fixed the link:  http://www.matweb.com/search/DataSheet.aspx?MatGUID=a2e79a3451984d58a8a442c37a226107&ckck=1

Here's a study done on the effects of E20 on various plastics, including Nylon 6,6:
http://www.mda.state.mn.us/news/publications/renewable/ethanol/e20onplastics.pdf

[ducatiz]

Nylon 6,6 properties:
http://www.matweb.com/search/DataSheet.aspx?bassnum=O2500&group=General&ckck=1

Here's a study done on the effects of E20 on various plastics, including Nylon 6,6:
http://www.mda.state.mn.us/news/publications/renewable/ethanol/e20onplastics.pdf

The Minnesota study is well known.  The material is not Nylon 6,6 but Nylon 6 or PA6. 

For those who don't want to sort, the results show a minus 0.5 of weight and minus 0.4 decrease in volume (size) with regular gasoline, a ~9% increase in weight and ~11% volume in the presence of E10 fuel, and a ~9.5% increase in weight and a ~12% increase in volume in the presence of E20 fuel.

As one increases the percent volume of ethanol in solution, the material expands/absorbs more.

The study does not consider any other properties of the materials, such as water absorption.

[Scissors]

The Minnesota study is well known.  The material is not Nylon 6,6 but Nylon 6 or PA6. 

For those who don't want to sort, the results show a minus 0.5 of weight and minus 0.4 decrease in volume (size) with regular gasoline, a ~9% increase in weight and ~11% volume in the presence of E10 fuel, and a ~9.5% increase in weight and a ~12% increase in volume in the presence of E20 fuel.

As one increases the percent volume of ethanol in solution, the material expands/absorbs more.

The study does not consider any other properties of the materials, such as water absorption.

Actually, the study did include water in the test fuel to better simulate the real world.  That would be why E20 didn't cause significantly more mass/volume gain than E10 even though it has twice the ethanol.

And I've been told Nylon 6,6 everywhere else I've read up on the issue.  So it's really Nylon 6?

Either way, the matweb link shows that Nylon 6,6 absorbs up to 9% (in terms of mass increase), which jibes very closely with the Minnesota study.  Nylon 6 is similar, with the ability to increase its mass by up to 10% through water absorption.

[ducatiz]

Actually, the study did include water in the test fuel to better simulate the real world.  That would be why E20 didn't cause significantly more mass/volume gain than E10 even though it has twice the ethanol.

And I've been told Nylon 6,6 everywhere else I've read up on the issue.  So it's really Nylon 6?

Either way, the matweb link shows that Nylon 6,6 absorbs up to 9% (in terms of mass increase), which jibes very closely with the Minnesota study.  Nylon 6 is similar, with the ability to increase its mass by up to 10% through water absorption.

The nylon type is stated on the tank itself.  Look on the bottom.  PA6.

The increase difference between the E10 and E20 fuels may in fact be significant, that's a separate study.  As far as the MN test's inclusion of water, it isn't the point of the study so they weren't looking at water absorption.  However, PA6's water absorption rate increases as the temperature increases. 

Put a half gallon of hot water into your tank and in the morning it will look like a balloon.

[BoDiddley]

I thought maybe I should stick this in here as I got zero response on it from the tech department, my tank had expanded length wise so much I could not get it off and on with out a screw driver.   Unless mine is a worst case scenario, just curious to know what is everyone doing about their particular problem?   They will keep expanding.

http://www.ducatimonsterforum.org/index.php?topic=46057.0

[Meerkat]

Had the same problem with mine, BoDiddley...as long as your talking about using the screwdriver to remove the tank from the bike hinge first. My latch was fully inoperable because the tank was swollen to the point that it was pushed all the way up against the ignition housing. Only thing to do is take it in for replacement. Don't forget to fill out the NHTSA complaint.