On 14/09/2015 17:43, Chris J Dixon wrote:
I want to make a simple rectangular planter (1), and don't want
it finished in any of the available garish preservative colours.

I thought I might use Wikes treated sawn gravel boards, with
fence posts for the corner pillars. I'm happy to go with a rough
sawn appearance.

I see that planters on sale seem to come with a plastic sheet
liner, though some of them are made of surprisingly thin timber.

Should I add a clear preservative, do I need a liner, or is it
probably better (and cheaper) to simply use substantial timber,
and replace when it decays?

(1) 600 mm x 800 mm, to match the concrete surround on a manhole
cover.

Chris

Sometimes (perhaps at this time of year?) the sheds seem to sell decking
boards off so cheap that they'd cost less than gravel board, and they're
more robust.