Icebox rebuild revisited

  • March 06, 2013 1:30 PM
    Message # 1235493
    I started a renovation behind my stove due to some leaks causing dry rot.  As all projects do it has expanded to include re-insulating the icebox.  I figured in for a penny in for a pound at this point.  I've been needing to rebuild the icebox since I bought the boat 9 years ago anyway so now is the time.

    Anyway, the icebox is coming out entirely so the tub itself can get new gelcoat inside, etc.

    I am also using 2 part closed cell 'expando-foam' for the new insulation.  It seems like I read that once the foam is in place to wrap the exterior with plastic so as to create a moisture barrier? Am I remembering correctly?

    Otherwise, any one have any useful tips? 

    Like maybe ideas how to better organize the interior. Right now I'm using a couple sliding baskets that hang on the 'ledges' but they are not really sufficient. Otherwise stuff just gets piled up on the bottom.
    Last modified: March 06, 2013 1:34 PM | Anonymous member
  • March 06, 2013 6:30 PM
    Reply # 1235708 on 1235493

    Mike,

    Done properly, use foam around the outside of the liner to just fit into the plywood cabinet.  Wrap the foam with aluminum foil for a radiation barrier, then wrap with plastic wrap to form a moisture barrier.  

  • March 06, 2013 9:27 PM
    Reply # 1235803 on 1235493
    Deleted user
    A problem I've found with pour in foam is when it cures it forms voids as it off gases and the R-value is greatly diminished.  My own box box when I tested it had an R-value of R-6.  After the rebuild the R-value is now R-40 +.  When I demoed it I found several large voids in the factory poured in insulation and the thickest at the bottom was about 4" and as the box tapers it was 1" or less.  I also did away with with the part that tapers along the hull as convection from the sun hitting the hull is a real killer. What is wanted is R-20 on the sides and top and R-30 on the bottom.  Something like Dow's Blueboard, at @r-4 per inch, 4" on the top,sides and 6" on the bottom works best. There are other materials that rate r-5 per inch but I haven' used them.  It becomes a problem getting enough insulation in the factory W32 box as the cabinet is narrow.  It isn't that it doesn't work or you can't make it better, it's just difficult to get optimal performance.  I warp with plastic for a vapor barrier and foil lining for UV protection also, although ASHRE studies for foil for UV protection are inconclusive

    Our own refrigeration is about 5 cu. ft. without a freezer and used 15-18 amps in the tropics.  With a freezer it would have been  @25 amps.  We felt we needed refrigeration space more than a freezer. It hasn't been a problem as Julie stacks frozen food in the bottom and it can last up to two weeks, but I do think most people would prefer a small freezer section.  Our performance is probably no longer obtainable and beware of cruisers "estimates" of power consumption.  When I've check other systems I've found almost all estimates were way off and many times used double what they thought.

    Jim











    Last modified: March 06, 2013 9:31 PM | Deleted user
  • March 07, 2013 6:06 AM
    Reply # 1236022 on 1235493
    "A problem I've found with pour in foam is when it cures it forms voids as it off gases and the R-value is greatly diminished."

    that was my concern when we initially thought about pouring the foam with the icebox in place.

    However, I'm hoping by removing the icebox, turning it upside down then pouring the foam (trimming to size after it cures) will avoid or at least minimize any voids.  At least it will be visible.

    "Wrap the foam with aluminum foil for a radiation barrier, then wrap with plastic wrap to form a moisture barrier.  "

    I've not heard about wrapping with foil.  Wouldn't foil actually serve to retain heat? Like a big heat sink?
    Last modified: March 07, 2013 6:20 AM | Anonymous member
  • March 07, 2013 10:20 AM
    Reply # 1236298 on 1235493
    Deleted user
    Mike, that might work.  When used in a factory it's carefully controlled by humidity and temperature so as not to leave voids , but still does.  What I did was discard the original box and fabricated a new one that was square, which would allow the use of material similar to Blue Board, although we used vacuum panels which are no longer available.

    Foil won't retain heat and has no R value.  The theory is that UV radiation penetrates the box and adds to the heat load, foil is suppose to reflect the UV.  As I said ASHRAE (American Society of Heating, Refrigeration, Air Conditioning Engineers) has done studies and they were inconclusive, but I would add foil, it can't hurt.

    Two other areas are the door gasket and drain.  If the drain is open and a poor door seal, heat will thermo siphon and add a tremendous  heat load. We have a double gasket and eliminated the drain.  The performance of the system is more dependent on the box then the mechanical equipment.

    Jim    
  • March 22, 2013 7:36 PM
    Reply # 1249852 on 1235493
    Hi all

    In 2011 I redid my ice box/fridge replacing the previous box which had no insulation directly under the counter and sweated terribly. I used the existing plywood box, had to remove the counter and the lid. I lined the box with foil then I replaced the foam with new blue board (three inches on sides and four to six underneath and three under the countertop) and used spray in stuff to try and fill the irregular spots (with creative cutting the blue board can fill in all but the weirdest spots. 

    Then I did a cardboard mock up to create the new freezer and refrig compartments and then had plexiglass boxes made to them, one for freezer and one for refrigerator. The last steps were to add the plexiglass top with openings for both compartments then putting blue foam on top of that, again using spray in foam to fill voids and then the new counter top. I was able to get two vacuum insulated lids for the compartments which have double gaskets (no longer made as far as I know). 

    I had the counter top made at a shop (they were a little intimidated since I showed up with a cardboard mock up and non-square measurements!) with formica on marine grade plywood. The original counter was screwed into the stringers on the inside of the box. I chose to fit the counter top to the edge of the box and then use the teak trim pieces to hold it down. I also replaced my old stove while I had the space available. There are some photos under my user profile too. pictures.
    (Ben: I added a return at the end of each image string to make it a URL and changed the last image to a finished view... nice group of shots - shows original construction and your modificiations very well. Hope you don't mind
    Jay )
    Last modified: March 23, 2013 8:12 AM | Anonymous member (Administrator)
  • February 21, 2014 8:14 AM
    Reply # 1502979 on 1235493
    Deleted user
    In the midst of a refit, W43.  I stripped the middle cabin re
    : new tanks.  Now I'm rebuilding galley.  This requires rebuilding the refrigerator.  I found a supplier of vacuum panels.  R40 insulation and thin.  $10-15 per square foot.  Minimum order is $1000.  I will be putting in an order shortly ( 4 - 8 weeks)  

    Anybody else interested in combining an order?


    Edward,
    Thank you for your inquiry into Kevothermal(formerly Nanopore Insulation)
    and our vacuum insulation panels. I have attached our technical data sheet
    and our PDF of general information. Our VIP's run in the $10-$15 per sq.
    ft. range and we have a minimum order of $1000.

    All of our work is custom and our blank size is 36" X 24" with a thickness
    range of 1/4" up to 1 1/2". Let me know if you can work with our minimum.
    Thank again and if you have questions just give me aor call or send an
    email.



    Rodney CheekDirector Sales Kevothermal
    100 Rogers Bridge Road P: 864-433-7024Duncan, SC 29334C: 770-313-3921
    SealedAir.comrodney.cheek@SealedAir.com

  • March 13, 2014 5:02 PM
    Reply # 1517337 on 1235493
    Deleted user
    The vacuum panel order goes in Monday.  If anyone wants in speak now as the minimum order is $1000 and they are R40 1 1/4" thick max 24 x 36 and 10-15 sq ft.