Plastic is the hardest thing in the world to get paint to adhere to. Mostly because of mold release and plastic is so slick in nature. This is why you see the oldest companies in the business still have paint that comes off from time to time.
You will have to get the mold release off before you do anything. I just use soap, water and a stiff plastic brush, but some folks flame treat them or use acetone..... and then some folks use both acetone and flame treating. Sand blasting the decoy has been the absolute best, but this is difficult for most folks to do since cabinet style sandblasters can be difficult to have access to.
I have painted hundreds and hundreds of plastics with several different things and tried several different preps.
Sand blasting the decoy has been the absolute best, but this is difficult for most folks to do since cabinet style sandblasters can be difficult to have access to.
Some easy to find products that I have had good luck with:
Krylon Fusion..... found at Wal-mart in the paint section. Prep according to can and then paint with oil-based paints. I just use this for a primer. It comes in gloss or satin.
Bulldog Adhesion Promotor.... found in auto paint supply stores for bumpers. Prep according to can and then paint with oil based paints.
Jansen Arts Multi-surface Prep and Jansen Arts paints...... found at The Duck Blind.... just do a search. Prep according to instructions and paint with the Jansen Arts paints.
Note: If you get season or two out of the repaints you have done better than most folks. Don't expect alot out of any process that you use. It's basically like flipping a coin. Experiment to see what works best and always follow the instructions on the products.