Blister in my tank's paint. Can it be fixed?

[Molly]

Hi guys. There's a pretty big blister in my tank's paint (dead centre in the following pic). Would you know if it's possible to get something like this fixed or is the only answer a full refin?

Thanks in advance for any advice you're able to offer.


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[Appowner]

Is that an actual blister or has someones knee been rubbing against it while riding?  Looks more like the latter to me but pics can be deceiving.

As for fixing it, being all the same color I'd say it's worth a try.  It's less complicated than you might think.  Do it yourself or do you plan on having someone do it for you?

If it were mine I'd give it a shot but then I have some painting experience from a hobby of mine.  If you do it yourself get the colors, primer, base, etc from HD (assuming it's a factory paint job).  Paint these days is not a simple rattle can experience.

I had a wrench attack my front fender some years ago.  Two different color pin stripes and two different met reds involved.  Took me two weeks but I did manage to sand it down, replace the base coat etc., build it all back up and clear coat it.  You can still see it IF you know where it is but no one has noticed it without me pointing it out.

[Molly]

Is that an actual blister or has someones knee been rubbing against it while riding?  Looks more like the latter to me but pics can be deceiving.

...

I had a wrench attack my front fender some years ago.  Two different color pin stripes and two different met reds involved.  Took me two weeks but I did manage to sand it down, replace the base coat etc., build it all back up and clear coat it.  You can still see it IF you know where it is but no one has noticed it without me pointing it out.

Yes. It's a blister. About an inch across.

My painting skills extend to old DuPont colour guitar refins using premixed rattle cans. I don't think I could do the more complicated layers involved in this; especially in such an obvious area. I wondered if anybody had had any success flattening it down somehow.

Wonder how common something like this is. I guess there must be a rust spot or something underneath that initiated the separation.

[Hossamania]

As you say, there is probably a rust spot or some type of imperfection under there. I doubt that it could be glued down with any success. The longer you let it go, the more potential for the rust to spread underneath. A good painter may be able to repair and blend the paint,

[kd]

Well I am going to be on the other team on this one.  If it was a plastic film I could see putting a pin hole in it and messaging it down but it's not.  Modern paints have hardeners in them and they break or chip when flexed after they have cured. Even the older lacquer applications had the thinners evacuate in a controlled manner until they hardened up also.  If there's a bubble of air under the paint it's a bigger problem.  The bubble is full of some sort of gas or fuel. Where did that come from?    I suspect there is pin hole in the tank.  If the bubble is soft or flexible it likely is gasoline. The petroleum product is blending into the paint keeping it soft and releasing it from the tank surface.

Because you are stuck with the blemish anyway, I would consider making a small prick with a pin near the bottom of the blister.  Place a fresh clean shop towel over the hole and see if it draws anything or any odor to it.  Even (with the fuel level above the blister) introduce a slight pressure into the tank and see if that forces any fuel into it now that there is a tiny escape hole. I fear it is an imperfection in the metal and fuel has contaminated the underside of the paint causing it to release from the tank surface.  Flexibility in the paint skin will be a good indicator of that.

[Hossamania]

I certainly can't disagree with kd's thinking on that.

[JW113]

How old is the tank/bike?

Maybe start by draining the tank and have a look inside. Any signs of rust, might be a good time to take them to a radiator shop, cleaned out, and Red Coated. You can try to fix the paint yourself, but it looks too big to me to try and fix with a touch up brush. This could be a blessing in disguise, though.

"Honey, the paint on my bike is trashed. It will cost as much to fix it as to paint the whole damn bike. What do you think of black with flames?"



-JW

[Appowner]

Well since the 'R' word (Rust) has been mentioned (honestly I didn't even think of considering the cause...Duh!).  I feel time is a bit more important now.

Since it has to be dealt with (i.e. repainted) anyway, I'd remove the thing and investigate.  Could mean the difference between repair and replace.

Maybe it was the MOCO but I seem to recall someone offering original tins in original factory colors for your year/model HD.  Wasn't cheap but at the price of custom paint these days it may prove to be the way to go.

Here's one place:  http://www.colormaniapaint.com/parts.html

If it is rust, a trick I have learned is to use super glue on the rusted area to stop the rust.  It's worked well for me on stone chips and the like on cars.  The glue is activated by moisture so any moisture in the chip is drawn out to set the glue.  Which then seals the chip, secures the paint around the edge and protects things until it can be properly repaired.  This is just a temp fix but I have found it pretty much stops small amounts of rust in its tracks.

[Molly]

Thanks for the detailed and thoughtful replies, guys. I'll let you know what I discover and how it works out.

Thanks again.

[thumper 823]

wet sand it dwn and shoot another coat of clear on it .

[Hossamania]

wet sand it dwn and shoot another coat of clear on it .

I believe what he has will peel right off down to hard metal if any real work is done on it. As he says, it is a "blister", the paint has lifted off of the metal but not cracked and let go yet to become a bare spot. It is not a flaw in the paint so much as a flaw in the "glue" holding the paint to the metal.
Ideally, one could use a syringe of glue and poke it through the skin, squirt it in there, and glue the paint back down, but doubtful a realistic solution.

[thumper 823]

I can't tell what is going on there from the pic,, but a clear coat  can lift from the paint.
IF that is the case, it is an EZ fix!

[Hossamania]

I can't tell what is going on there from the pic,, but a clear coat  can lift from the paint.
IF that is the case, it is an EZ fix!

The clear coat isn't lifting from the paint, the paint is lifting from the metal.

[thumper 823]

That is called a redo.
No EZ fix

[JW113]

I think a lot of this depends on Molly. What kind of guy is he, really?

Is he the kind of guy that would be happy with a patch job to the current paint, and maybe it's "better" but not perfect?

Is he the kind of guy (like me) that any little cosmetic boo boo would drive him insane?

Or is he the kind of guy that is perfectly happy owning and riding an old bike, and accept that it is an old bike, warts and blems and patina and all.

By the way, I've not seen too many, if any, shooting clear over an old paint job turn out too well, or last. Just sayin'...

How about this: Start trolling on ebay, maybe get lucky and find a used right side tank in your color that's in reasonable shape?

-JW

[Appowner]

My suggestion would be to find or borrow a tank he can use while his gets repainted.  That way there's no time limit on the painter and he can continue riding while the work is being done.  It is summer after all in his neck of the woods.  One key to painting is the prep work and that should not be rushed. 

And I think I'd get both halves done even if he stays with the original style.  All paint slowly fades with time in the sun and matching one side to the other could prove difficult.  Plus if the culprit of this blister is rust, it might be prudent to suspect more rust in other areas of the tank to include the other side.  Best to take it all down to the metal and see what damage is really there.  Would hate to see him do the right side this year only to discover later that he needs to do the left side next year.

[thumper 823]

Leave it and call it original patina ...