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Re: Europa-List: bouyancy

Subject: Re: Europa-List: bouyancy
From: Fred Klein <fklein@orcasonline.com>
Date: Wed, 10 Jan 2007 20:19:32
All,

Posted points are well taken...as I said, I intend to do some research 

on the subject and will report back any information I gather...adding 
foam may well be one of those seemingly simple notions which, upon 
investigation, is fraught with peril.

Fred

On Wednesday, January 10, 2007, at 03:51 PM, NevEyre@aol.com wrote:

> 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.
> --
>
>


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