Well here is how the story goes. I acquired a replacement ( Urethane ) bumper for my daily driver as the old one had significant road rash from the previous owner. It is in pretty good shape but a different color. The new bumper is silver and the car is a darker green. Well I wet sanded down the new bumper with 400 then 600. I then painted it with a spray paint I acquired through the internet. I don't remember what the company name was, any way supposed to be high quality etc. and was fairly expensive at $20 for a 12 oz. spray can. After I painted the bumper which I used the entire can giving the bumper three coats, it looked kinda blotchy. Well I convinced myself that it was the lighting and it was probably fine, so I went ahead and sprayed a full can ( three coats ) of clear. Well today when I got it into natural daylight I could see that it hadn't been the lighting and the color was indead blotchy. In a few areas where I guess I got the paint on a little heavier the color is pretty true to the vehicle, but in other areas it is much lighter and very inconsistant. Where did I go wrong here? Was it not enough paint? Was it going over a different color without priming? Was it using the spray can? ( I would doubt this as it isn't a quality issue). I will have to sand down again and start over, so I don't want to make any more mistakes. I am not looking for a perfect job here just something that will faily closely match the existing paint and look half decent. Also I forgot to mention that I don't own a spray gun, so that as wellas material cost was the rteason I acquired the base and clear in spray cans.

You said it yourself " Where I guess I got the paint on a little heavier the color is pretty true".

You get what you pay for.

IMO getting a "decent" looking job out of spray cans is slim to none and slim already left the building.

It's not possible to get even coverage with spray cans on something as large as a bumper. Even if you could, the paint would peel off because spray can paint doesn't contain any flex agent. To get a decent job you'll need to invest in some spray painting equipment and use primers and paints intended for use on plastics or accept the fact that it's not going to look OEM.

You might try looking on the SEM website. They make flexible aerosol paints for upholstery so they might offer something for bumpers. You still won't get professional looking results, but at least the paint won't fall off.

Tom

It's not possible to get even coverage with spray cans on something as large as a bumper. Even if you could, the paint would peel off because spray can paint doesn't contain any flex agent. To get a decent job you'll need to invest in some spray painting equipment and use primers and paints intended for use on plastics or accept the fact that it's not going to look OEM.

You might try looking on the SEM website. They make flexible aerosol paints for upholstery so they might offer something for bumpers. You still won't get professional looking results, but at least the paint won't fall off.

Tom
Flex agent is over rated. I did not use any on the repaint of my bro's plastics (bumpers, rockers, etc). We did not have any cracking/peeling for the year after that, until he wrecked it. Even then, with the bumper flexing over 24" inwards, there was no paint cracking/peeling. :cool:

Flex agent is over rated. I did not use any on the repaint of my bro's plastics (bumpers, rockers, etc). We did not have any cracking/peeling for the year after that, until he wrecked it. Even then, with the bumper flexing over 24" inwards, there was no paint cracking/peeling. :cool:

You were lucky.

One of the items on my to do list is to repaint the bumper on my son's TransAm because someone didn't do it properly and the paint is cracking and peeling. Can you get away with not using flex agent? Maybe, if you use a urethane paint, but why take the chance of having to repaint when all it takes is a bit of flex agent to make sure the paint stays put? Cutting corners is fine right up to the point where it bites you in the butt.

Tom

Flex agent slows the drying process, after a couple months it's basically gone anyways.

Flex agent slows the drying process, after a couple months it's basically gone anyways.
I've heard this elsewhere, also. Eventually there will be no flex-agent. It's more for the handling of parts as they're assembled on to the car.

Flex agent is only useful when the bumper is painted off the car, even then it is NOT needed.
Plus they just evaporate out later down the road, they dont keep the paint flexible forever.

Proper prep and quality paint you don't need flex add., however, automotive paints have a flex limit