[Rhodes22-list] ...on spray foam and other musings....

[Goodness]

To decrease interior condensation.  Now that i think more about it tek-foil might be a better option.



On Feb 14, 2012, at 9:29 AM, R22RumRunner at aol.com wrote:

> Bob,
> I'm just curious, why would you want to insulate the interior hull of a  
> R22?
> 
> Rummy
> 
> 
> In a message dated 2/14/2012 8:32:59 A.M. Eastern Standard Time,  
> spreadgoodnews at gmail.com writes:
> 
> Thanks  Rob.  I am building out a 43' steel sailboat hull.  I am finishing  
> the final interior epoxy coats now then i will spray closed cell 
> polyurethane  foam all over the interior hull over the stringers and ribs.  Then i 
> have  read i should spray a fire retardant elastomeric paint over the foam to 
> resist  ignition in case of an interior fire. This foam will insulate as well 
> as  contribute to the oxygen barrier of the epoxy.
> what kind of foam did boston  whaler use in their hull construction?  My 
> friend has a bw dinghy hull  that weighs about 300 pounds! Thats like 20 
> gallons of absorbed water!   My understanding of closed cell foam is that if it 
> is cut after spraying it  will absorb some, but i am not sure how much.  I 
> think the Rhodes has the  good stuff in there like the foam that floats 
> docks.(closed cell  polyurethane?)
> Also is a pool noodle polyethelene foam? You can get that  stuff in sheets 
> and it would be nice to insulate the rhodes interior hull  with.  It wont 
> absorb water either.
> Thanks,
> Bob
> 
> 
> 
> On  Feb 13, 2012, at 9:58 PM, Rob Granger <rgranger at sbc.edu>  wrote:
> 
>> Okay I didn't want to seem heavy handed when I stated  before that I was
>> "almost certain" that Great Stuff is closed cell  because there is a lot 
> of
>> controversy on this topic and to be fair,  not all spray foams are the
>> same... but I'm a chemist and I felt it  was necessary that we get this
>> straitened out since many of us are DIY  boaters...  so on the topic of
>> spray foam
>> 
>> Some  spray foams are latex and therefore open celled (DO NOT USE LATEX
>> SPRAY FOAM ON YOUR BOAT) but Great Stuff expanding spray foam is a
>> polyurethane-based foam and not a latex foam.  So unlike the latex  spray
>> foams it is *closed cell*.   And you should not be  afraid of it absorbing
>> water.  It will (however) stick to the  hull like ... well a polyurethane
>> glue (think Gorilla glue).  So  the bag idea is the way to go if you ever
>> want to get it out again...  or line the area with visqueen before you
>> spray.  I've used both  approaches and they both work fine...  I can post
>> pictures if  anyone wants to see the results of the bag or visqueen
>> approach.
>> 
>> So to clarify, polyurethane foam (Great  Stuff)  is *closed cell*... so it
>> is fine to use on your boat,  even in low spots.
>> 
>> The pink and blue foam boards at Lowes and  HomeDepo are also great to use
>> for floatation foam.  They are  *extruded* polystyrene and so they will 
> not
>> fall apart into tiny  little balls that make a mess everywhere... (Iike
>> cheap styrofoam  will).  I have about six 3" boards cut up and crammed 
> into
>> my  MacGregor 22'.  And all of the little left over pieces are in a  bag,
>> crammed into a tight spot and filled with spray foam (along with  some
>> packing peanuts I got in Christmas boxes this year).
>> 
>> A note on packing peanuts.  They're now two kinds.  The  old-school kind 
> are
>> made of styrofoam.  Those are fine to use on  a boat.  The other type are 
> "*
>> green*" and made of  cellulose.  The cellulose peanuts will dissolve in
>> water.   Obviously you do not want to use those.  It is easy to tell which
>> type you have.  Drop one in a glass of water and wait a bit.  Or you  can
>> bite one  :-)
>> 
>> If you are skeptical about the  closed cell nature of Great Stuff 
> expanding
>> foam...(and it is not a  bad thing to be skeptical) you can read about it 
> on
>> the Dow Chemical  site... you wont hurt my feelings if you do... I promise
>> :-)
>> 
>> Here is the link to the Dow Chemical site
>> 
>> http://building.dow.com/na/en/products/sealants/windowdoor.htm
>> 
>> 
>> my 2 cents.
>> 
>> ... the other Rob
>> __________________________________________________
>> To  subscribe/unsubscribe go to  
> http://www.rhodes22.org/mailman/listinfo/rhodes22-list
>> 
>> For  the list Charter and help with using the mailing list and archives 
> go to  http://www.rhodes22.org/list
>> __________________________________________________
> 
> __________________________________________________
> To  subscribe/unsubscribe go to  
> http://www.rhodes22.org/mailman/listinfo/rhodes22-list
> 
> For the list  Charter and help with using the mailing list and archives go 
> to  http://www.rhodes22.org/list
> __________________________________________________
> 
> __________________________________________________
> To subscribe/unsubscribe go to http://www.rhodes22.org/mailman/listinfo/rhodes22-list
> 
> For the list Charter and help with using the mailing list and archives go to http://www.rhodes22.org/list
> __________________________________________________