"Peter Clinch" wrote in message
...
riverman wrote:
"John-news-group" wrote in
message
...

I am thinking of filling the old bages with polystyrene beads

Has any of you done this sort of thing, if so any thing to look out
for

My first thought is that, if the old bags let air out, the new bags
will let
water IN, and there's no easy way to drain them. You might make them
a LOT
heavier this way..

If you don't trust air bags I'd be inclined to go in the solid[1]
shaped
foam direction, 'cause that seems to be a working thing you actually
see
in use. In the bow you can carve them into an ideal footrest, though
this isn't such a Cunning Plan if more than 1 person uses the boat, or
you want to use the same buoyancy in several boats.


[1] not /really/ solid, but YKWIM

In answer to the OP:
I suspect the spaces in between the polystyrene beads would soon fill
with water, which would rapidly become rather smelly if not drained
regularly.

Adding to the suggestions already made:
Why not fill the air bags with 2 part expanding foam? The airbag stops
the foam from sticking to the boat so if you ever want to take it out
you still can.
Small tip: put the air bag in the boat before adding the foam. A little
foam gets a lot bigger, very quickly, and expands in all directions if
not contained.
It also gets quite warm as the reaction takes place. It sticks to just
about everything including your skin. Experiment with filling something
disposable if you haven't used expanding foam previously. Build up
layers rather than pouring loads in at once. Overdo it and you could
distort your boat.

David
Not a fan of distortion