Paint experts...What causes this???

[bjfish11 5,000+ posts]

Ok here is the procedure I went through.

Had all the body work done on a box, primer and was ready for paint.

I start spraying down my base coat and realize on of my corners looks like *** and needs a bit more primer. So I stop with the base coat. Then I shoot some more primer on the box and get the corner fixed. I wet sand it all back down to get it ready for paint AGAIN.

Well, I sanded through some of the primer back down to the original basecoat, but I didnt think it would be a problem. So I go to spray my basecoat again and everywhere I sanded through the primer to the original base coat did this little "crackle" (see pic).

So, what causes this? Has this ever happened to anyone? Its happened to me a couple times, so Im wondering why?

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[wilzyx 5,000+ posts]

that actually looks kinda cool, and cant you just sand it down and do it over again?

 

[bjfish11 5,000+ posts]

that actually looks kinda cool, and cant you just sand it down and do it over again?

Nope, it just does it again, and again, and again.

I tried.

 

[dirtye30 10+ year member]

you have sime kind of oil or water in your paint or clear. or you have two differant products that have a differant base and will pull away from each other. try using a differant \product.

 

[wilzyx 5,000+ posts]

even if you put more primer and then paint?

 

[bjfish11 5,000+ posts]

you have sime kind of oil or water in your paint or clear. or you have two differant products that have a differant base and will pull away from each other. try using a differant \product.

But its wierd, because it only happens in the area I sanded through the primer back down to the paint. So it cant be anything to do with oil or water in the paint, or gun, or airline.

And its the exact same base coat that was originally used.

 

[bjfish11 5,000+ posts]

even if you put more primer and then paint?

Well, no. I have to sand it down and re-primer the whole thing. Im trying to figure out what is causing this so I can avoid it all together.

 

[bumpweLL.nYc 10+ year member]

before you lay your base take off your fingerprints with prep-sol.

 

[bjfish11 5,000+ posts]

before you lay your base take off your fingerprints with prep-sol.

I forgot to say that I always prep before I lay a coat of anything.

 

[supa_c 5,000+ posts]

Looks like you put paint remover on it...

 

[Chevyaudio 5,000+ posts]

My guess was going to be fingerprints (the oil in them from touching the box after you sanded it) but you already ruled that out.

 

[bjfish11 5,000+ posts]

My guess was going to be fingerprints (the oil in them from touching the box after you sanded it) but you already ruled that out.

Yea, I cant figure it out. It only happens when I have to repaint and I sand through the primer. But it doesnt happen every time. Thats why I find it very wierd. Its not like I change my procedure. Its the same thing everytime. //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

 

[candyman206 10+ year member]

I'm in auto body right now. This happened to a kit car that we had to color match. I don't know what it is called but it will keep on happenning until you sand it all the way down. THe parts you cut into past the primer are now going to keep on getting softened by the new paint. So it's just gonna be a whole mess if you don't just start all over again. Sorry for the bad news. It's something related to being THERMAL PLASTIC, which is something like ice and butter you could keep on melting it but THERMAL SET things can never be put into original form. THe pain is THERMAL PLASTIC is constantly gettin melted by the new paint that has solvent in it.

 

[bjfish11 5,000+ posts]

I'm in auto body right now. This happened to a kit car that we had to color match. I don't know what it is called but it will keep on happenning until you sand it all the way down. THe parts you cut into past the primer are now going to keep on getting softened by the new paint. So it's just gonna be a whole mess if you don't just start all over again. Sorry for the bad news. It's something related to being THERMAL PLASTIC, which is something like ice and butter you could keep on melting it but THERMAL SET things can never be put into original form. THe pain is THERMAL PLASTIC is constantly gettin melted by the new paint that has solvent in it.

It doesnt do it EVERY time, thats why it is very strange.

But thanks a lot for the info. I guess from now on, if I ever have to repaint, and sand back down to the original basecoat, I will just shoot some more primer before attempting to paint again.

Thanks again for the info.

 

[lukedogg 10+ year member]

was the part previously panted? Are you sure the primer is compatable with the paint you are using? I had this happen to me when I was painting my Dad's truck. I had to sand through the sealer and I just sprayed a 1 part primer over the parts I sanded through. But since the sealer was 2 part, I had the same effect you are. So I just resealed the fender. This fixed the problem.