In message , Thomas Prufer
writes
On Fri, 25 Nov 2011 22:05:01 +0000, Tim Lamb
wrote:

How do I stop the foam sticking to the plywood? And, how long does it
take before full expansion is reached?

Polyethylene film. Bin liner, whatever. Peels off the foam a treat.

Yes.

Cling film was suggested as well.

On realising how long the cure/full expansion time is I decided to fall
back to the *trim off the surplus* method.

regards

--
Tim Lamb