Auto body repair & detailing: blisters in paint, rear wheel wells, color paint

Question
Mike
I noticed a couple small blisters on my rear wheel wells and fixed them. They multiplied and I fixed it again (no holes) I have done this three times and it comes back worse every time I do it. I used good paint and clear coat from auto color paint store took it down to bare metal and even tried jb weld the last time thinking the bondo was porous. I know why they call it cancer because on matter what I try it keeps coming back. is there any advice you could give me on how to take care of this problem before it eats holes in my truck.
                                  Thanks, Ken

Answer
KEN

BLISTERS INDICATE A CHEMICAL REACTION I STAKING PLACE DUE TO TRAPPED SOLVENTS.
YOU SAY YOU HAVE TAKEN DOWN TO BARE METAL....BUT THINK THE BONDO WAS POROUS?

I ASSUME THAT YOU TOOK DOWN TO BARE METAL AND REDID THE BODYWORK?

HMMM....DID YOU PUT JB WELD ON THE BARE METAL AND THEN COVER THAT WITH BONDO?


TAKE DOWN TO BARE METAL AND THEN CLEAN THE BARE METAL WITH A WAX AND GREASE REMOVER.
REDO THE BODYWORK MAKING SURE THAT YOU DO NOT ADD TO MUCH HARDNER TO THE BONDO.....

SAND ,PRIME,SAND,PRIME AND FINAL SAND AND PAINT.

THAT SHOULD DO IT.....SOUNDS LIKE YOU SOMEHOW ARE POSSIBLY TRAPPING CONTAMINENTS UNDER THE PAINT.

RUST STARTS FROM THE INSIDE AND WORKS IT'S WAY OUT TO THE SURFACE....DOESN'T SOUND LIKE THAT IS THE PROBLEM.

MIKE