In message o.uk, Dave
Liquorice writes
On Wed, 21 Oct 2009 18:01:55 +0100, Bill wrote:

but I have no idea what the plastic component of it is. It is the usual
blue or green heavy stuff they use on lorries.

Are they "plastic" I thought they where canvas thus cotton. 25 ft
square and plastic I wouldn't expect to be particulary heavy, decent
bit of canvas on the other hand would be rather heavy.

Canvas would be repaired using sail making techniques, sewn on
patches etc I expect you can fine the stiches and methods to use on
the web. I can't see why the same techniques wouldn't work on a
plastic tarp provided you took into account the possibly larger weave
and the layout of the "threads" making it up.

It's definitely heavy! It is quite a close weave - sort of coated
canvassy stuff. The cotton or whatever inside is white, but the blue
'plastic coating covers this up on both sides. One side is fairly shiny,
the other shows the pattern of the weave. It's nothing like the 'covers'
they sell in Poundland or Halfords.
When I've taken it back to the makers to repair, they have stuck patches
on in some way - no stitching.

Anyway, time is running out. As soon as a capable son comes home we'll
have to dart across the country and heave it on.

Thanks everyone, I'll think about all the suggestions for next year.
--
Bill