I got a used stone deflector for my 92 F-150. I stripped it down to bare metal. Then wiped it down with grease and wax remover then sprayed on a rust converter, because it had a few small rust spots. I bondoed up a couple of small dings. I then wiped it down again, let it dry then primered it.
I let it sit over night and put a second coat of primer on it, with a light sanding between with 1000 grit. And wiped it down before the second coat.
I let it sit over night again then sanded it with the 1000 grit, wiped it down again and painted it. I let it sit over night , then again sanded it with the 1000 grit. I wiped it down again, let it fry and put a second coat of paint on it. I then did it all over agin the next day.
Now the problem. I didn't get back to it for 2 weeks. I light sanded it down with the 1000 grit and wiped it down, and let it fry. i then started spraying the clear coat. And I didn't even get it all coated before the spider webbing started.
Both the primer and the paint are laquer, and so is the clear coat. The weather was good temp, and it was all done inside the garage. So I don't have a clue why it spider webbed. My only thought is maybe I should have used 400 or 600 grit instead.
when I stripped it down, the paint was peeling off in spots. One piece was about 4" long when it came off. I had sanded all of the paint off except a few non issue parts, and blew it off with the compressor, and more of that paint just blew off. So obvious to me, none of the paint actually adhered properly. Thus leading me to believe, I should have used a courser grit.
What do you think? Anything else i should have done different?

 

How old is your paint? Maybe the wrong thinner for your weather? The paint just blew off.... Down to what? Primer or your Rust Converter? I MIGHT be willing to bet you did not sand your Rust converter and the primer was unable to grip and bond with it.

What kind of primer did you use? a high build ( or sanding primer ) or a epoxy primer?

 

You definitley should have gone with a courser grit (400-600 max for best adhesion), but I don't know if it would peel off like that just due to that. I somewhat agree with Ohio above - most likely a chemical reaction....incompatibilty somewhere, likely in the rust converter. POR 15 specifies a "tie-coat" primer to adhere to it.

 

I would still like to know what stayed put on this and what all lifted off..... That would help in trying to figure out what happen ware.

I'll take a Somewhat agree with me in the paint and body area ! Means maybe I'm learning something!

 

I can't remember what brand the rust converter is, but I only used it in a few spots.
The primer stayed put. I had to sand it all off. 2 coats of this.
The paint which I had 2 coats on is what peeled off.
The primer, the paint, and the clear coat are laquer. I made sure that I used all the same stuff, and they are all from the same company.
I went and bought 500 grit wet and dry sand paper, because that's all they had. I wanted 400 grit.
I'm also going to not use the grease and wax remover after each sanding betwen coats. My friend who used to spray cabinets for a living said to use just plain old water from a spray bottle, so I'm going to do that.