Topic: Paint Disaster

[Dunk]

Well I washed it and the whole side didn't peel off or anything crazy. I'll see if someone local is able to mix up some Polynesian Blue Metallic and can repair and match that. Worried it'll get worse or start peeling/chipping more if I let it go forever. Just my luck though, this is why we can't have nice things...

Still curious other people's thoughts on whether the paint should be able to withstand a gas spill. I'd be worried with some occasional splash or drops from filling it'd peel eventually, usually hold my hand around the nozzle to keep any off the tank particularly when using unfamiliar pumps.. Hate that some are like on/off and no inbetween.

[calj737]

My opinion from that picture is that the paint is too far up the lip of the filler neck, allowing the trapped vapor to get behind the paint due to the paint being immersed in fuel constantly.

I would remove all the paint until you reach the lower side of the lip and then seal it there with clear coat.

[seanbarney41]

My opinion from that picture is that the paint is too far up the lip of the filler neck, allowing the trapped vapor to get behind the paint due to the paint being immersed in fuel constantly.

I would remove all the paint until you reach the lower side of the lip and then seal it there with clear coat.

+1, if you go back in this thread a ways, you will see where I posted that every painted filler neck I have seen in the last several years has had this happen.  I have seen some seal the edge of the paint with a clear epoxy (the glue, not the paint!) with good success, but it looks kinda globby.
     I think it actually takes several months for modern automotive clear coats to fully cure into their full gasoline/ethanol resistance.  What are ya gonna do?  Not ride for 4 months?

[Tews19]

Sean my feelings are hurt! I thought I soaked the tank and cleaned it before you got it? Glad the tank held up after all those miles!

[seanbarney41]

Sean my feelings are hurt! I thought I soaked the tank and cleaned it before you got it? Glad the tank held up after all those miles!

absolutely no worries...that tank is still looking and working great...you had less than a gallon of Evaporust down in the bottom.  The bottom was really clean.  Tipping the tank and sloshing just wasn't getting the top.  I bought more evaporust and it didn't work, so I bought 4 gallons of vinegar and it all cleaned up nice and still is to this day.
     To get back on thread, my painter also painted the entire filler neck, with the exact same result as Cadunkle's.  I just shaved the lifted portion off with a razor blade and forgot about it.  You have to look pretty close to see this portion of the tank when the lid is closed.    ...but then overall, Caduncle's bike looks way nicer than mine and such details may be unacceptable for him.

[PeWe]

Well guys thanks for the opinions. Seems the cause of this disaster was mostly my own fault but probably had some other factors:

1) Filled too full
2) Put it under the tarp while still warm so probably got really warm under there (and it was a fairly hot day already) so the gasoline expanded as it warmed
3) Leaking filler neck connection (compounded by possibly a clogged vent which would allow some pressure to build inside) ... and again because it was filled too full
4) Poor paint prep ... Since the red was painted directly over the black paint with no primer it was much more easily affected by the fuel.

So... mostly my own damn fault and partially a questionable paint job.
............

IW

I have got my tank overfilled several times. That happened back in the days during holiday going south thru Germany, Italy...
The gas stations beside Autobahn had personel filling the tank when I sat on it, usually filled up to the very top. It happened several times that the gasoline started to expand and flow all over the tank and down to the very hot engine when I parked the bike on side stand. Steam cloud of gasoline  after the gas stop for having a smoke, coffee or food.
The bike did not turn into flames... strange. I was nervous when I switched on the ignition.

This was with my avatar tank that I painted. No water crap paint.
2k primer + 2k red + 2k clear. All of them withstand gasoline.

NO problem with gasoline or paint flaking off during the 7 years I used the bike or the following 20 years in barns.

I have ordered a compressor and sprayguns that soon will arrive to my garage.
My future paint job will have 2k paint all the way. I hope that the HONDA colors are available as 2k paint

[lrutt]

I can show you 3 tanks I painted that had no problems at all. Acrylic enamel with hardner. Granted they showed no signs of bubbling before painting so no need to test, Just really good prep.

If that neck was leaking before I'd think it would have showed up in the old paint job. If it's coming down off the cap sealing surface then crappy prep as it should never bubble like that. I've had bad gas cap gaskets and paint never lifted like that. The venting comment. nope. If you didn't vent your bike would not run. These old bikes vented both ways, not like the new bikes that capture vented gas in the charcoal canister. The only thing I would say is that when painting, I always mask off the gas cap sealing surface. From what I've seen often times the factory does not do that, but I do. I've painted an untold number of tanks and never had a lifting problem like that at the cap or at petcocks (next most popular spot to go). And like I stated, I go simple on paint, plain old acrylic enamel with hardner. Granted I've not had to do a resto to match a candy color that required a more complicated process. If that was a single stage it could be a simple process but with that color, it will be complicated and need a full strip.

I feel your pain though and am sorry this happened.

[nvr2old]

I've painted 100's of gas tanks, and the one thing you have to do is seal the tape edge at the filler neck.  The tank doesn't have to leak to produce the problem you have.  Even fumes will eventually get under the raw paint edge.  I use JB weld to seal the edge.  Mask off an 1/8" over the paint edge, smear a small amount over the exposed raw edge, remove the masking, let it dry for 24 hrs. and that seals off any exposure to the paint.  It's a very simple and yet very effective fix to the problem.

[Muckinfuss]

We must have been taught by the same guy back in the 60's when we had two choices....acrylic lacquer for trick painting and acrylic enamel for an automotive finish.  I used regular epoxy glue then.  The only difference I do now is after the epoxy seal is done at the lip and cured, I run a flex-hone in the filler neck and then immediately do my clear coats without sealing off the filler with tape.  The urethane creates a belt and suspenders type of seal over that edge.