(May be US specific issue due to environmental laws) I just noticed tonight that a section of paint around the fuel cap had bubbled up and turned soft. Now the gas tank was painted almost a year ago and has been subject to minor splashes of fuel in the filling process for some months. The paint itself was one of those from a spray can with hardner. In the past I've had almost no problem with paint with hardner added. But that was back when we could get the hardner as a separate product and mixed it with the paint in a gun. So let me differentiate. This is the rattle can which has hardner in a separate compartment and you strike a button on the bottom to allow the hardner to mix with the paint. And this paint is a one coat, not the two part which has, a can of color and then a can of clear coat.  I'm wondering if anyone else has had this problem arise and if so what their solution was and how well did it work.

 Know any products that will prevent or cover up such problems?

thanks
jjefferies

It's the chemistry in the paint. As near as I can tell, the OEM paint is a polyurethane based where most aftermarket paint, especially rattle can is acrylic based. OEM paint is also baked to further crosslink the molecules, making a stronger film.

There's not much you can do beyond being careful not to splash fuel when filling the tank, not using the side stand with a full tank, and making sure your gaskets are in good condition.

The same thing is happening to my paint.  I had my tank professionally sprayed with a two-part epoxy primer and two-part polyurethane finish.  After several years, this is what has happened to the paint around the filler cap:

I had the painter repair that spot and the same thing has occurred again, and it's slightly worse now than when this picture was taken.  I don't know why this is happening other than there is something in the fuel that eats away at paint, but it is frustrating.

robmack wrote:The same thing is happening to my paint.  I had my tank professionally sprayed with a two-part epoxy primer and two-part polyurethane finish.  After several years, this is what has happened to the paint around the filler cap:

I had the painter repair that spot and the same thing has occurred again, and it's slightly worse now than when this picture was taken.  I don't know why this is happening other than there is something in the fuel that eats away at paint, but it is frustrating.

Other than the color that looks exactly like mine. I was wondering if there is any product out there sort of like a gasket (wrong word) looking that could be glued around the fuel filler opening. Yeah! Yeah! lots of reasons not to. Just trying to think out of the box.

If indeed a Polyurethane finish was used, the problem may be due to the lack of curing before exposure to the fuel. Unless the paint is baked immediately after application or allowed to air cure for at least a month before exposure to fuel you will probably have issues with paint breakdown.

The ethanol and additives in modern gasoline are brutal to paint. Prolonged exposure will damage almost all aftermarket paints. The only defense is to get a good cure of the paint and scrupulously avoid fuel contact. Even then, some damage is to be expected, it's the price to pay for having the benefits(?) of having ethanol blended in our fuel.