Hi Bob / All.
The blue foam is pretty well closed cell, the type that is definately closed
cell is coloured orange, and sold as ''Flotation Billet'' as opposed to
''Insulation Billet of the blue, as used in the Europa.
The blue will not pick up too much water unless immersed at great depth,
where the pressure will force the water into the cells, so fine at sea level !
It weighs 2lb. cu.ft, and a cu.ft will support 60lbs in fresh water.
Most of the foams that are injected, are open cell, so will soak up water
like a sponge, the pour in types supplied to the marine trade for bouyancy are
very inconsistant in use, sometimes they tend to expand to ''open cell'',
which again will soak up water. [I have seen boats foamed with this ''TOUCAN''
foam that have absorbed so much water they barely floated]
The other problem with the ''pour in'' foams [ as opposed to the blow in,
injected types] is that the finnished volume can vary, you can never be sure
how far it will go. I have witnessed floors ripped from hulls. Temperature of
the two foam components. and the space being foamed will have an effect. The
warmer the foam and / or space, the further it will go.What can happen, is
that it fills a space entirely, and ''gells'',[ so cant escape from the vent
hole] then carries on expanding, with sometimes disasterous results.The power
of
foam expanding has to be seen to be believed! I have seen a Range Rover that
someone with a grievence had poured some of this two pack foam into, puffed
it out like a hedgehog, totally round by the time it had finnished!
A Classic, I am sure , will have more than enough volume of foam to stay
afloat indefinately, an XS will eventually fill up, but possibly ''lurk'' nose
down just below the surface.
Cheers,
Nev.
|