What type of UV-resistant (fade-resistant) paint is best as the outer coating of a rain barrel? The barrel is made of polyethylene. It will sit in a greenhouse, so other than direct sunlight and slight temperature variations, it's relatively protected from other types of abuse.
I would like to use black paint to maximize solar-heat absorption.
Basically the paint needs to be durable, adhere well and won't crack or come off over time.
Best Answer
“Adhere to polyethylene” is going to be your problem. It Does Not Like things sticking to it.
I suppose you could voraciously scuff-sand to create a surface with a lot of “tooth”, then paint it in epoxy, hoping for a mechanical bind. Ideally epoxy primer like Amercote, but that is too dangerous for consumers to use. I suppose something like West System 105 would do. Sunlight will quickly destroy the epoxy, so you’ll need to topcoat it with something. But paints stick a great deal better to epoxy then to polyethylene.