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

[hillbillypolack]

Has there been ANY movement on Izz's aluminum tank?  I was ready to pony up for a Beater tank and had been contacting them to that end.

For whatever reason, Simon at Beater is no longer reachable.

[ducatiz]

Unfortunately, this is taking a long time.  There are a lot of issues getting the bottom side of the tank right. 

The goal is to have a tank that can be used on multiple bikes with the original round EFI pump.  That goal has presented fitment issues.

The top is done.  I thought I would have something by now, alas. 

[krista]

Unfortunately, this is taking a long time.  There are a lot of issues getting the bottom side of the tank right. 

The goal is to have a tank that can be used on multiple bikes with the original round EFI pump.  That goal has presented fitment issues.

BTDT... Lots of fun. BTW, the 900 engine is the tallest of all the air cooled engines. CAD was able to confirm the impressions hot cooling fins made on my tank in one of its previous iterations.

[Dry Martini]

So what is the best way to seal up the pump hole on the bottom, prior to coating with Caswell sealer?

[ducatiz]

So what is the best way to seal up the pump hole on the bottom, prior to coating with Caswell sealer?

Pick up a $4 piece of lexan at home depot.  They sell small pieces of it about 10x10.

The hole is just a bit smaller than a CD.  So you can trace the opening on the lexan with it. 

Cut the sides of the lexan down to about 1" outside the circle you traced so you can lay it on the hole and then trace the outline of the outer surface of the hole.

Cut the lexan to fit so that it lies flat on the hole with your CD traced circle in the center.  Then mark off the locations of the screw holes and drill them.  The screws are 6mm.  That's just a tad smaller than a 1/4" drill bit.  Drill all the holes and make sure they line up well.

Now that you've got a piece that will fit and can be attached, put it over the hole and put a couple of the screws in to hold it in place.  Trace a line around the outside of the filler hole just inside the screws.  Now remove the lexan and flip it over and put a THIN bead of RTV silicone adhesive along that line.  You need this because the lexan cover will not seal.

If you want to make your life easy, pick up a #9 stopper for the filler hole.  You can also use a hole saw and put a 2" hole in the middle of the lexan and use a #11 stopper there.  The stopper in the filler hole will make it so you don't have to worry about stuff coming out while you're rotating the tank.  There is an overflow hole in the filler which you need to plug as well.  I used a piece of rubber glove shoved in with the stopper.

For the mixture, pick up some disposable SQUARE tupperware, like that Glad stuff and some wood stirrers from home depot (paint dept gives them out for free).

Read my comments on how to rinse the tank, and how to reduce the caswells.  Xylene only.  Acetone will eat the tank (not aggressively, but it does attack nylon).  Xylene is 100% compatible with the tank material and the caswell's reduces well with it.  I use no more than 1.5 oz for the whole mixture of caswells. 

Dump the contents of the LARGE can first into your mixing bowl.  I put the xylene in next because it keeps the small can from fixing the mixture better.  Use the stirrer for about 2-3 full minutes.  Scrape the sides and bottom often to keep it mixed.

Have a roll of paper towels handy
I usually use about 4-5 pairs of disposable nitrile gloves.  I change them often to prevent spreading the caswell's.
Use painter's tape to cover the outside of the tank.  You don't need plastic wrap or anything.  The caswell's will wipe off easily if you use a paper towel quickly. 
The xylene is the pregnant dog you ahve to worry about with the paint -- it will literally start stripping the paint in about 10 seconds. 

I rinse the inside of my tanks with about an ounce of xylene before pouring in the mixture, but I don't dump it out, I put about 10 paper towels in a wad into the filler hole (no lexan cover yet) to absorb it and then remove it carefully.


The filler hole is actually HDPE and the caswells will not adhere to it well (FYI).  I always wipe the outside surface very clean so it seals properly when you out the plate back on.

[Desert Dust]

So what is the best way to seal up the pump hole on the bottom, prior to coating with Caswell sealer?

+1 I coated a tank for an s2r 1k last night and I drilled a piece of plexiglass to match the fuel pump holes, but I put a standard rubber garbage disposal cover (fit almost perfectly) down before bolting down the plexiglass so that it would seal. Used a sink stopper for the gas filler hole.

I had no issues with leakage of Caswells during the process.

By the way, thanks to all who contributed by providing me with these ideas.

[Dry Martini]

Thanks to both of you for the info.

[J-Speed Inc.]

Other than the Caswell coating, has anyone had any luck with anything else?  I've heard mixed reviews on the long-term effectiveness of the coating, was wondering if anyone used anything like StarTron ethanol treatment (popular in the boating community) to keep the ethanol from making the nylon in the tank expand?

The tank on my 07 S2R 1000 has now expanded to the point where it can't be unlatched and is pressing against the key switch.  Seems like heat makes the tank expand faster as when the bike was sitting inside for a week, the tank didn't change.  When I took the bike to work and it sat outside in the 90+ degree FL heat for 8 hours, it expanded.  I will be going through Ducati to get a replacement tank under warranty, but would like to know if there's anything I can do to keep the new tank from expanding.  We can get Rec 90 (non-ethanol fuel) here, but it's tough to find.

[duccarlos]

Tiz would be the ultimate authority, but last I heard the coating has been the most effective resolution. Multi owners, the group that have been dealing with the issue the longest in the Ducati community, have shown cases of the coating, if applied correctly, have lasted years. Startron, or any other item that claims to fix the issue by chemically changing the fuel, does not work.

[ducatiz]

Other than the Caswell coating, has anyone had any luck with anything else?  I've heard mixed reviews on the long-term effectiveness of the coating, was wondering if anyone used anything like StarTron ethanol treatment (popular in the boating community) to keep the ethanol from making the nylon in the tank expand?

Where have you heard mixed reviews on the coating?

I've got a 2+ year old coating in my first tank and it's going strong. I used a fibre-optic camera to inspect it and it's holding up very well.  There might have been issues for people who did not prep the tank correctly, and the factory "test" used 100% ethanol and who knows what kind of tank or if any prep was done.

None of the additives will make any difference.  The primary issue is water.  The additives just make the water burn in the engine, they do not "remove" it.

See my other posts with info about the ingredients of those additives.  Most are kersoene, naphtha, mineral spirits, even ethanol etc.  They just increase the octane of the gasoline so the water burns more smoothly.

[J-Speed Inc.]

Not looking to start a war or anything, but from what I've read on other Ducati forums, it has been a mixed bag of results using the Caswell coating.  You're right, this might be due to improper surface prep, but I would bet it's pretty difficult to rough up every square inch of a crazy shaped plastic gas tank.  In the past I've used a handful of drywall screws on metal tanks, but nothing ever got into the seams very well.  My research so far showed the coating having issues at the seams.

Has Ducati changed the tank plastic formulation to get rid of this problem?  Is Ducati just going to give me the same tank which ethanol will eat again?  My bike is ridden regularly and the tank will be emptied after 5 days or so, but the odds are not in my favor if the warranty replacement tank has nylon like the old on does.

[ducpainter]

The tank material is the same.

Your best bet is to coat the new tank with the Caswell coating.

[ducatiz]

Not looking to start a war or anything, but from what I've read on other Ducati forums, it has been a mixed bag of results using the Caswell coating.  You're right, this might be due to improper surface prep, but I would bet it's pretty difficult to rough up every square inch of a crazy shaped plastic gas tank.  In the past I've used a handful of drywall screws on metal tanks, but nothing ever got into the seams very well.  My research so far showed the coating having issues at the seams.

Has Ducati changed the tank plastic formulation to get rid of this problem?  Is Ducati just going to give me the same tank which ethanol will eat again?  My bike is ridden regularly and the tank will be emptied after 5 days or so, but the odds are not in my favor if the warranty replacement tank has nylon like the old on does.

The issue is prep.  There is no need to scuff the tank, but that does help adhesion. The #1 issue is that the rinsing was not done sufficiently.  Gasoline prevents adhesion.  Using a proper rinse with something to cut the gas, drying the tank, and then rinsing again with a nylon-compatible reducer (xylene is the best choice) you will get sufficient coverage.

I've used both of Caswell's coatings and they are the same except for color.  The color one is better because you can see where it is running.  Reducing it is absolutely necessary to get coverage everywhere.

The replacement tanks are the exact same stuff.  Some replacement tanks were older than the tanks they replaced.  My 2005 S2r tank had a 1/2005 manufacture date.  The replacement tank has an 8/2004 manufacture date.

[J-Speed Inc.]

So it sounds like the best idea is to get the replacement tank from Ducati and coat it with the Caswell coating cut with Xylene.  Only other alternative is only run ethanol-free gas, however, that would get annoying quickly.

[ducpainter]

Even ethanol free fuel is not completely free of moisture.

Just coat the tank.

Reduce the coating enough so it flows freely and easily all over the tank and you won't have trouble.

If you can coat the tank before any fuel is put in it so much the better.