Starting my own thread about this so i dont take away from others threads.

Had car painted 2 yrs ago, within 3 months the paint was chipping off my front bumper in large sheets. The bumper was a aftermarket stock replacement and came primered, I had the whole car shot with black and 2 coats clear for 600$ i did all the prep work.

Anyway I stripped the bumper down with aircraft stripper and got it down to the poly, then i sanded the whole bumper with 220 grit to get it all smooth. I wanted to shoot this with 2K urethane primer and then hot rod black.

questions

1) is 220 grit to rough for primer? I know it should be like 400 for primer and then 600 grit for base coat. But i want the frigin paint to stick this time.

2) i had some gouges in the bumper and im sure i cant use regular bondo body putty to fill them so ill need a special putty?

3) ive read that flex additives do nothing so im not using them, but im also not using adhesive promoters... is this ok not to use?

 

I also wanted to add that after i spray the bumper with the 2K urethane primer I was going to wet sand the bumper with 600 grit before the hot rod black gets sprayed.

What do you guys think?

 

i would use an adhesion promotor forsure urethane primer won't stick to plastic very well. I paint new bumper covers all the time and always use adhesion promotor, haven't had one fail yet.

 

You need to got to your local paint store and get plastic adhiesion promoter.it comes in rattle can or can.you need to put it on before you prime

 

what brands do you recomend? And how much would I need to get? i would prob do both front and rear bumpers.

I also do not have a local paint store for cars, mostly just home/commerical paint.

 

also what about the 220 grit? is that too rough? i wet sanded 220 it its got some drag with my hand but it doesnt seem too course.

 

seems that the 3M stuff i wont be able to get except online and then have to pay shipping. Anyone know about the dupicolor stuff? its pretty cheap and it looks like i could pick it up around here at advance autoparts etc.

http://shop.advanceautoparts.com/web...ci_sku=7140919

EDIT: I also know that bulldog is a great product however getting it would be the same as the 3M stuff and i wouldnt have it for a few days and pay shipping.

 

i just used the bulldog stuff on my bumper. its in primer right now hopefully painting soon.
i think that 220 is good for primer, if you put on a couple coats then you can sand it smooth anyway. i personally dont trust much of anything from advanced auto myself, but it should be fine. i'd just be skeptical.

one thing though is to remember that its ok to get a good deal, but try not to let quality go for a couple bucks. i've gotten some cheap stuff before and had to replace them immediately (starters from autozone) but then again its your car so do what you want lol

 

thanks, I just purchased a can of the bulldog adhesion promoter as ive stripped the bumper all the way down to bare plastic. I also got a can of the evercoat poly-flex putty as I have some gouges that i want to fill on my bumper.

Ive read mixed reviews on how to apply the bulldog, maybe you can help me out. Ive read to do a light coat then another coat thats thicker. Some ppl have problems with the paint bubbling or not hardening completely. How did you apply it? and how long did u wait before priming it? And how much of the bulldog did it take to cover your bumper? i only purchased one can to do my front bumper as i hope when the rear bumper arrives from thirdgenranch that its in decent shape and only needs to be sanded and primed.

I should add that after the promoter i plan to prime it and then let it dry completely, then wet sand again with 600 before final coat.

 

I stripped the decals from the used rear bumper from thirdgenranch, it had some gouges also that i will be using the filler for. So since there were gouges I ended up sanding down to the polyurethane. If there are spots all over the bumper where the polyurethane is showing does that mean I have to coat the whole bumper in the bulldog adhesive promoter? or can I just prime it? Reason I ask is that maybe 15-20% of the polyurethane is showing on the rear bumper otherwise its all the stock 2tone paint.

hoping to prime these this weekend if i get the chance, so answers ASAP would be appreciated

 

i followed the directions on the can. i used two coats, but i did the same amount. i dont like the chance of anything running on me. i only had to do a small area cuz i had some front bumper damage from pulling into a parking spot with a high cement tire chalk. i just went to bare plastic and used it. it says its ok to apply primer 5 minutes after application. i waited a few hours with a heater on it (it was in march, and im working in an outside pop-up-garage thing and it was cold anyway so i had everything being heated lol) and so far it seems ok. but i only painted the car a couple days ago

 

When u sprayed the spot with the bulldog did it build high enought to make a noticble differnce after it was primed/painted? I don't want any high spots to show through. Which is why coating the whole thing will make an even layer

Anyone else? Wat about my rear bumper? Should I spray the whole thing or just the spots that went to the polyurethane?