Paint around gas cap bubbling

[feederbb]

Went for a long ride on Saturday with tank bag on.  Filled it up once on the ride but no fuller (is that a word?) than I have before, and yes I'm anal about spilling ANYTHING even a drop of fuel anywhere on the bike.  Did a lot of altitude change on the ride and brought her home with 1/4 tank, fuel light flickering a little here and there.  Went out to give her a good clean up, pull the tank bag and there is some bubbling of the paint just in back of the cap.  I'm bummed because the paint is pristine and now it's not!  First question would be why did it happen and now that it has what can I do to stop the spread?  One thing for sure is that I take the bag off when I'm done riding from now on but you hate to do that all the time thinking it might be hard on the paint also (granted not as hard as what happened).  I'm thinking the tank/cap gasket has probably gone by by.  Any sugestions?   Thanks.  Kevin 

[Pat Conlon]

aaaawh, cripes, I hate to hear that Kevin. I hope it's not too bad.
Question: Are the bubbles under the color coat or just under the clear coat?
#1 as you know, you got to figure out how it happened so you can stop it. A leaky gas cap gasket is a good bet. You're sure you didn't overfill? I'm not sure what type of tank venting your '89 has but you want to be sure it's clear.
The tank bag definitely hurt the situation, however it's not the tank bag's fault. It would be a good bet that 99% of us use a tank bag on our FJ's.
#2 You have to remove the blisters so you can get to the damage surface to clean & prime for your color and clear  They *will* enlarge if you don't take action. Kinda like a cracked windshield.
As painful as it sounds you need to open them up (Xacto knife #11 blade) to do this...
A dab of Midnight Black paint and a dab of clear to level the surface is the best you can hope for...

Take some close up picts and post them here... Pat

[feederbb]

thanks Pat, they are through to the color and actually down to the clean metal.  I think what my plan of action will be to take the tank off and try and have a local paint shop paint a "ring" or the top part of the tank in a black color in a uniform shape that will blend in with the paint scheme of the bike.  Don't know if they can do it or not but possibly another couple coats of clear over the whole thing to help protect it from future use of the tank bag.  Just such a shame to see what happened to such a clean tank.  It litteraly took my breath away when I pulled the bag off and saw....oh shit!!!  I was going to wash the bike but spent the next couple of hours just miserable comiserating on what happened.  Hey it's just a material thing but I keep my stuff pristine and it was like someone kicked me in the nuts!  As I told my girlfriend, hey at least it didn't leak enough and have a fire or something while we were on it!  It's a bike, I'll get over it.  It's not new, we just need to take action on how to deal with the situation.  Metal can be repainted, rubber replaced, but sometimes skin is hard to replace and lives can never be.  Life is good.  I'll get over it!  If your headed to Willits have a great time and thanks for all the info so far.  You guys are great and I hope to make it next year, hell I will make it.  Mark my word!  I'll have new tires, time on the bike and my financial BS with the ex will be far behind me by then.  Motor safe!  Kevin.

[carsick]

Yeah Kevin- Look where you want to go, on bikes and in life. You'll get it fixed, don't worry!

[Marsh White]

Kevin - that sucks!  I'm not 100% sure that this was the cause; but don't top off the fuel tank when you fill up.  The gas will heat up and expand and it can overflow if you filled it up to the brim...then get caught under a tankbag.

[markmartin]

  Filled it up once on the ride but no fuller (is that a word?) than I have before, ...  Did a lot of altitude change on the ride :

To reiterate what Pat and Marsh said about venting and a full gas tank,...I'd check the overflow tube at the back of the tank to make sure it's not kinked, pinched or plugged.  When you say "Did a lot of altitude change on the ride"  I'm assuming up and down steep hills maybe? 

If I fill my tank on the center stand and then go park the bike on the kick stand I can get overflow from the overflow tube.  I'm thinking going up and down hills would with a full tank of gas may cause a little overflow.  if the tube is plugged it's gonna want to go somewhere..

Just a guess, but an easy check.

[feederbb]

Think I know what happened.  After much thought and personal ass kicking, I realized we filled (on the center stand) then shortly after stopped and got a drink.  I didn't think much of it because in "time" it was probably an hour later but we were going through Zion park and it was a lot of waiting, slow speed riding, aka, not using much fuel at all!  Duhhhh, only went a short distance out of the park and stopped for a drink and the girlfriend to make a phone call.  Probably sat there on the side stand for 20-30 minutes in the sun (yes of course I always park in the shade when available).  Probably burping some fuel out the cap and then proceded to ride all day with said fuel on top of the tank.  Since it wasn't sitting in the garage and we were pretty much moving the whole day, or wind blowing, I never noticed or smelled it!  bummer.  What's done is done.  Took the cap assembily off today and all the rubber looks good.  Didn't realize until I took it off 4 of the screws are just for show!  Going to a check out a local paint shop or two and a guy in the neighborhood who has a custom cycle business and ask a lot of questions.  Lesson learned, no blood or skin lost.  It's all good.  Kevin.   

[DB Cooper]

Just noticed this post.
I had the same thing happen on my RD. I know the cap was prone to leaking a little after a fill (especially if I was stupid and put too much fuel in ), and it's usually not a big issue. Given the chance, gas will evaporate long before it will eat through the paint. Until one day, I left the tank bag on and the gas had no where to fume off, what a mess. Now that I have the FJ, as a precaution, every once and a while I will lift up one side of the tank bag (it's a magnetic bag) to let it air out just in case I've put too much fuel in or whatever.   
Great idea if you can match up a painted ring around the cap!
Kevin

[feederbb]

Yes I have learned that lesson.  I probably did fill it too full since it was the first real "long" ride we were going on.  After talking with a local paint guy we decided to repaint the whole top portion of the tank.  The top of the tank from the stripes up is just plain old black and is very thin, not much left of the clear over it either.  There is quite a step from the black to the blue pearl color which is very thick so he's going to do the black and maybe a couple coats of clear over it possibly helping it to stay nice longer.  We will see what this guy is made of!  He does tanks and custom painting for some of the bike shops and has had some work at SEMA and other car and bike shows, been a local auto/bike painter for over 20+ yrs in same location so that in itself says a little something.  We will see early this week!  Kevin

[rktmanfj]

Yes I have learned that lesson.  I probably did fill it too full since it was the first real "long" ride we were going on.  After talking with a local paint guy we decided to repaint the whole top portion of the tank.  The top of the tank from the stripes up is just plain old black and is very thin, not much left of the clear over it either.  There is quite a step from the black to the blue pearl color which is very thick so he's going to do the black and maybe a couple coats of clear over it possibly helping it to stay nice longer.  We will see what this guy is made of!  He does tanks and custom painting for some of the bike shops and has had some work at SEMA and other car and bike shows, been a local auto/bike painter for over 20+ yrs in same location so that in itself says a little something.  We will see early this week!  Kevin

The stripe is a decal under the clear coat, I think.

Randy T
Indy

[feederbb]

Update on the tank paint job!  The guy did a great job!  I took it to the "local" paint and body guy, kind of a once man show.  He masked off the Yamaha on the tank that's in the black, re-shot the black and new clear over the black and the letters.  It looks really good.  Couldn't be happier.  I can't use my tank bag for a couple of weeks till the paint is totaly set up but hey, threw the soft saddle bags on and tried them out on Saturday.  They work great and don't even know they are there.  Miss the tank bag for ease of access but you can't complain if your still riding, right?  So I have learned my lesson, not filling her as full, no side stand when full, and checking to make sure if I do fill her to make sure no more lost tears looking at bubbled paint!  Kevin