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.

  • Wrap it in black plastic.
    – Solar Mike
    Commented Jul 7, 2020 at 19:26

1 Answer 1


“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.

  • Thanks, but I guess you're only suggesting the undercoat?
    – Jinren
    Commented Jul 7, 2020 at 22:27
  • “Only”??? Prep and primer are the key to it. Get that right and topcoat barely matters. Commented Jul 7, 2020 at 23:46
  • I feel like this is an incomplete answer. What topcoat would fit the bill?
    – Jinren
    Commented Jul 14, 2020 at 18:48
  • @jinren depends. Are we talking direct application onto run of the mill poly, or has the surface been prepared? Commented Jul 15, 2020 at 1:51
  • Assuming we used the epoxy undercoat like you suggested. What topcoat?
    – Jinren
    Commented Jul 15, 2020 at 3:02

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