I'm getting ready to paint my EG and there is one spot that will not stay smooth where it was filled. I have sand blasted this spot down to bare metal, because it was a slight rust hole, then filled it and sanded smooth and shot some rust preventative primer over it for the time being and the **** is still bubbling through slightly. It's above the back right quarter/fender right above the tire. What should I do to get this to stop for good? Any help is appreciated.

 

I'd cut out the rust and make and weld in a patch. Or if it is small just weld the hole up. If you just want to fill it without doing this use duraglass instead of regular filler as it will not absorb water from getting wet on the backside as regular body filler will.

 

You could use some POR15 on it.

 

what exactly is that, some kind of spray??

 

POR15..its a paint that chemically stops rust from reforming.

it almost sounds to me like your bubbles are gas/moisture trying to escape not rust reforming...

if it is rust, welding in a patch would work very well...

there are also plastic patches you can buy that you glue over the existing panel, then remove the seams by using filler and repaint

 

Rust keeps coming back like child support checks.
From my experience POR 15 didn't do ****. Just cut and patch, prime seal and spray. Pull out quater linings (rubber). Good luck

 

If por15 didnt do ****, you didnt use it right.

You said it was a rust hole. If bondo has any access to moisture, its going to bubble and come off.

Rust needs moisutre. So once you figure that out, your problems will stop.

 

por 15 didnt do much for me either, but then again i think the rust needs to be compeltely encapusulated in the por 15