A messed up plastic prep

G

GLHX

I was getting ready to primer some plastic parts with spi epoxy primer.

I scuffed and cleaned the plastic well and then sprayed some bull dog adhesion promotor on it. The can says allow 30 to 40 minutes for flash time. I got distracted and waited 50-60 minutes. Then primered it with black epoxy with reducer 1:1:1. Do I need to take all the primer back off.

I also did the bumpers the same way.....EXCEPT for scuffing them. I was going to prep them by using a gray scotch Brite pad and some paste. Again I got distracted and forgot to scuff it. My wife called and needed something and kept me on the phone for 20 minutes while I was doing all of this.

The bumpers came primed with the cheap primer they use....I scuffed the primer with a red pad and went through in some spots.....there was bare plastic spots showing and the primer was so thin that the regular wax and grease remover was creating a lot of static. I switch to plastic cleaner jx101 ppg and it took the primer off. I stripped the bumpers with this stuff easily. I don't know of it was scuffed from the factory before that primer was put on there or if the plastic was made into the primer like a gel coat. So I had he bumpers all stripped

Then forgot to scuff them.....then let the adhesion promoter sit for 50-60 minutes instead of 30-40 like it said on the can.

Then it says the promoter is good up to 24 hours. I want your opinions on where to go next.

- - - Updated - - -

How bad is this mess.
 
Why don't you let them dry real good and then feather back a small area to see if it is sticking. It doesn't sound real good to me, but maybe you got lucky. Sanding into it is the only way to know for sure. If it is sticking, reprime the area and go on your way. If it's not, well, you got a mess on your hands. I do not recommend Bulldog. That junk bit me on the butt one too many times. Use SPI adpro if you are using SPI primer, imo.
 
It's bad if it's bad but I can use flex paint remover and it should remove the primer from the bumper fairly quickly. Some of the trim painted was straight abs......that could be a problem. As paint remover melts abs. Why does this ad pro say its good for 24 hours? I thought it flashed off and left a tacky substance. Them you primered it and they dried together glued to the plastic. I sprayed some parts with the bull dog and didn't primer it. 2 hours later I checked it. It didn't feel tacky at all. What will it do if it doesn't work. I'm going to let the primer dry for 4 days. If it doesn't work will it chip off?
 
Personally, I don't see any issues.
After 48 hours you could do a 2" tape natch test but i don't really see the point.
 
I was worried because all the training videos I see show to scuff the bumpers with a gray scotch Brite pad and prep paste.
I got distracted and just happened to skip that step. But the bumpers had primer on them already......I was told that the bumpers that come primed are not scuffed.....the plastic is poured over the primer and the plastic hardens bonding the primer to it. I was told they spray gel coat into the mold....then primer....then plastic. I didn't scuff it.
The other parts I did scuff.....just not the bumpers

I'll do a tape test and see.

I was under he impression that you let this stuff flash for 30-40.....and with spi adhesion promoter you wait 15 minutes and you have to spray it directly with primer after that or it dries quickly and is ineffective.

What I'm seeing is that that's only for flash off and this stuff works for a while before it can't be coated with sealer. The can says 24 hours. I won't use bull dog again.....I didn't know spi sold adhesion promoter or I would have used that. I'm not a fan of rattle can stuff anyway.

If this primer is going to come off......what tape should I use to test it
 
Duct tap is best, press down 4 inches and leave two inches lose. then snatch it back fast as you can pulling it towards you.
 
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