On Tue, 05 Feb 2013 13:00:23 GMT, Harry Bloomfield wrote:

Caravan, alloy outer skin which is damaged and I need to repair it with
car body filler.

The problem is that car body filler is reputed to attack polystyrene
which is just behind the alloy skin and used for insulation. So I need
something to separate the two.

I guess sliding something like ordinary cooking foil or a plastic bag
into the gap would be tricky. Ex takeaway container ali foil, Ex rigid
plastic food container, cardboard from cerial packet?

How big is the hole/damage? Will CBF stick well enough/be thick enough to
withstand the inevitable flexing of a caravan body?

--
Cheers
Dave.