Re: [bolger] Re: foam flotation

Vince:

I'm not a chemist either, but I have some practical experience. Use only
the expanded polystyrene foam. The two part is polyurethane, and is no good
for flotation, unless as someone mentioned, it is kept completely dry until
the day it is needed.

Chuck

> I am not a chemist and I don't understand all of the measurement units
> shown. The test dealing with water absorption % by volume seems easy
> enough to understand though. It was given as 6.0 max and 4.0 max for the
> two grades of foam they sell. Am I correct in assuming that after
> absorbing 4% by volume of water, it would still have 96% of its original
> flotation? I don't know if this type foam is only available in blocks or
> if the two part foam-in-place products would have similar test results.
>
> Vince Chew

I am quite interested in this topic as Bolger recommends foam flotation
for may of his designs including the Dakota I am building. I have seen
floating docks at marinas which used unprotected blocks of foam. I
wonder what type it is. I did come across one web site with pictures of
marina docks floating on unsheathed foam. It is called expanded
polystyrene and the Canadian manufacturer gives test data for it. The
web site is:
http://www.mansonvilleplastics.com/newpage5.htm
I am not a chemist and I don't understand all of the measurement units
shown. The test dealing with water absorption % by volume seems easy
enough to understand though. It was given as 6.0 max and 4.0 max for the
two grades of foam they sell. Am I correct in assuming that after
absorbing 4% by volume of water, it would still have 96% of its original
flotation? I don't know if this type foam is only available in blocks or
if the two part foam-in-place products would have similar test results.

Vince Chew