[Dragon J]

Hi guys- it's been a while- I've lurked many times but everyone seems to get quick advice so I've remained silently reading. I'm hoping now that you can help me with a mystery bubble... As many know I've painted cars, bikes, murals and graphics for about 20 years. I did a bike in 2003 and the guy just noticed a 'mystery bubble' appearing on the side of the tank. The paint is Martin Senior base/clear deep red metallic. The bubble is not near the graphic or any bodywork. It is about the size of your little fingernail and raised only about a 32nd of an inch or less. It is not the clear only as it is red and perfectly round. He said it gradually grew over a 2 month period and has not grown any further. It looks like a gremlin got inside and tapped it once with a ball peen hammer! No other area on the whole bike is affected. Can anybody guess what could have caused it? I see no remedy but to repaint, although it is not discolored or very obvious - just a little bubble. I have pics but you can barely see it in them- it's a - 'you have to be there' - kinda thing. Any help is appreciated, guys!!! Thanks-DJ

[BarryK]

Not knowing what you prepped the metal with or used as an undercoating because it has not grown real fast I'm going to say its rust (speck) Gasing.
Caused by print left on metal or use of acid etch primer.
If you get rusty water out of it and goes to the metal when you blow on it, its caused by one of the two.

If you push the bubble will it disappear for a few minutes?

Short cut:
Pop it with a pen and mix some clear up and dab the pen hole.
Next day 2000 and had buff.

Who knows how long will last?

[BondoKing]

Nice trick Barry

Matthew

[Dragon J]

Thanks for the quick reply Barry- I sanded to bare metal, removed damage (not in this area) and used a good primer surfacer from Martin Senior followed by a sealer. There was no rust I saw, but you may be right that a speck could have formed (the humidty at the time was about 90% and it was my old drafty garage before the new shop!) I will mention this possible test/remedy to him and see what he thinks (he's in Colorado- I'm in Iowa!) and Thanks Barry! DJ

[Henry Moran]

Originally Posted by Dragon J

Hi guys- it's been a while- I've lurked many times but everyone seems to get quick advice so I've remained silently reading. I'm hoping now that you can help me with a mystery bubble... As many know I've painted cars, bikes, murals and graphics for about 20 years. I did a bike in 2003 and the guy just noticed a 'mystery bubble' appearing on the side of the tank. The paint is Martin Senior base/clear deep red metallic. The bubble is not near the graphic or any bodywork. It is about the size of your little fingernail and raised only about a 32nd of an inch or less. It is not the clear only as it is red and perfectly round. He said it gradually grew over a 2 month period and has not grown any further. It looks like a gremlin got inside and tapped it once with a ball peen hammer! No other area on the whole bike is affected. Can anybody guess what could have caused it? I see no remedy but to repaint, although it is not discolored or very obvious - just a little bubble. I have pics but you can barely see it in them- it's a - 'you have to be there' - kinda thing. Any help is appreciated, guys!!! Thanks-DJ

I had simular problems on offroad bikes, even with sticker graphics on their
petrol tanks, then I found Out the plastic tanks are manufactured with
microscopic holes in the plastic, for safety reasons so the tank can breave
to let the gas vapors escape, if it happens were theres a sticker it forms
a bubble.
Henry Moran.