Ice box question.

[seadog6532]

We want to improve the insulation on the ice box, and want to know what others have done. I have heard there is no insulation or very little around the ice box. Is there a trick to removing the counter top or is it better and easier to just drill some holes and spray in some expanding foam. We would prefer not to put the insulation inside and make the ice box smaller but will if we can't find a better way.
Thanks
Mark and Anna of Arianna.

[Jeff Barnes]

Mark and Anna,

I have CD36 which has a pretty large ice box to begin with, but with the traditional poor insulation. I added insulation to the inside using rigid foam panels (2" I think) all around. I then cut white plexiglass panels and covered the foam panels. Sealed seams with white silicone chalk. I added insulation mainly because I installed an Adler-Barbour SuperCold Machine. This was a much easier job than insulating the outside, and I Ithink with better results. I know the insulation has been a big improvement, and the volume of the "fridge" is still adequate for food, ice cubes, and sufficient beer for my deck apes.

Jeff

[Troy Scott]

Mark,

Instead of insulation, Cape Dory installed a "second shell" to create a "dead air space" around the icebox. This is basically how a thermos bottle works, except thermos bottles actually have a vacuum in the space. This "second shell" is better than nothing, but actual insulation is better. In my CD36, I drilled a grid of holes from the inside of the box into the dead space. I used canned, expanding foam to fill the space. The displaced air escaped from the other holes in the grid. This stuff goes a long way. I knew that when I started, so I was conservative, but I still used a little too much. The outer shell expanded outward a little more than I wanted, and the inner walls of the box bulged in slightly. But, on the bright side, the insulation is generally thicker! I had to recut the movable plastic shelves a little shorter to get them in place. Fixing all the holes was not difficult. I used a countersink to clean up the holes and provide a surface to bond to. Then I mixed up epoxy, mill fiber and q-cells to fill all the countersunk areas. I over-filled them slightly and held the mix in place with masking tape. When it all cured, I sanded it flush and used white bilge paint to resurface the inside of the box. Be sure the foam you use is not hygroscopic, otherwise the new insulation will get waterlogged over time. Also, the space under the countertop on my boat was partly insulated, but there were large areas with no insulation at all. I bought a sheet of 1" thick blue foam from Lowes and cut pieces to fill the gaps. I sealed those with epoxy and later stuck them in place with thickened epoxy. Then I added another full layer of sealed 1" blue foam (painted white) to the whole underside of the top. I also replaced the drain with better hardware (with a plug this time) and then I added some more insulation around the drain. I haven't yet decided what to do about the lid. I may just replace the seal and not worry about it anymore. or I might get fancy with it, I just don't know yet. Good luck!

[barfwinkle]

Hi Mark

Tory mentions a process used by a former frequent contributor to this board Captain Larry DeMers. Although I think Larry's process was more elobrate than Troy's. Anyway, I did a search for the thread and could not fine it. Somewhere in the archives is a fairly detailed explanation that Larry used to improve the insulation on his CD 30 DeLaMar.

I don't know what his previous user ID was, but using Larry DeMers doesnt return the expected results! OR I could be missing it entirely. Maybe someone else can be more helpful!

Good luck

[hmeyrick]

I've only just recently been working on my ice-box.

In mine, the original box was insulated with fibreglass batt insulation inside the "shell", and some sort of cork insulation underneath the countertop. As a dockmate gave me a used Adler Barbour machine, I decided to add insulation inside the box so as not to kill my batteries.

What I did is this- line the box w/ 2" blue polyurethane foam board, glued in with the minimally expanding variety of "great stuff" brand pu spray foam, which nonetheless expands enough to fill the voids between the curved ice-box walls and the straight-edge foam board. I covered the board w/ 1/4" ply- again using "great stuff" as glue- and then glassed the plywood in w/ one layer each of cloth and matt. Just last weekend I covered the glass w/ linoleum. I laid the linoleum on the deck, and went for a sail on a friend's boat so the lino would have time to get nice and flexible in the sun. When we got back I discovered that it had blown away, possibly into the drink. So I bought me some new lino, affixed it w/ polyester resin and caulked it w/ 5200. It looks very sharp- just the thing for a Cape Dory- and looks about as bullet proof as all heck.

I've admittedly lost interior ice-box volume, but on the other hand I don't think I need to carry a great pile of ice either. Especially when I get that Adler Barbour up and running.

[Steve Laume]

I have been poking around my ice box to explore the options. I am torn between the expanding foam on the outside with additional rigid foam inside vs ripping the whole thing out and laying up rigid foam to start over.

With spray foam it will be hard to know for sure if all voids have been filled. I would give that a try for sure but wonder how much harder it will make the rip out job if I do go that way. One thing to keep in mind if any of you start spraying foam into voids is that there are some water hoses running under the ice box. You would do yourself or the next owner a big favor if you protected those runs from being incased in foam. I was able to get pretty good access to the under side of my box by cutting a small panel out inside the cabinet next to the box. There is no insulation around my ice box. Anything would be an improvement over the existing situation, Steve.

[oldragbaggers]

I found Larry DeMers thread and moved it to the top of the board.
Becky

[Boyd]

Hi All:

I just reinsulated my refrigerator box and one of the most striking things I discovered was how much cold escapes through the drain and lid. I little convection current develops with hot air entering the lid through CD's miserable seals and exits as cold air through the drain.

If you plug the drain and remake the lid seals there is a tremendous improvement possible.

I added insulation panels to the underside of the lid and the counter top. There was NO insulation at the top. This was really apparent on hot humid days as the countertop and lid would sweat.

Boyd
s/v Tern
CD30 MkII
Fort Lauderdale, Fla.

[Troy Scott]

Folks,

The icebox drain should be replaced with one that has a plug, similar to a bathtub drain. This will stop the constant and wasteful downward draft. Also, the "second shell" I mentioned meets the inner skin near the drain, so there is no dead-air space there in the original design. Along with filling the cavity with foam, you also need to add some insulation on the outer bottom around the drain. Don't forget the underside of the countertop, where you should add an inch or two of foam, but not the canned kind. Just use sheet foam there. Once you've installed the plugable drain, the seal around the lid becomes much less critical, since you've stopped the draft at the bottom. In my opinion, filling the cavity is the easiest way to drastically improve the icebox. In my boat the cavity averaged just over two inches thick. You don't need to worry about not knowing if you've filled the cavity of not. You will know, because expanding foam will come out of all the holes in your grid. If there are one or two holes where no foam came out because it didn't expand enough, just add a little there. You also don't need to worry about covering hoses, etc.. You aren't filling the space between the icebox and the hull; You're filling a dead air space between the two shells of the icebox. If you aren't sure whether or not you have the inner and outer shell "thermos bottle" type of icebox, just drill a hole through the inside wall of the icebox and probe the space. If you choose to use this method to insulate your icebox, be very conservative with this foam. Use it and then wait a while to see what happens. If you quickly use enough to see foam coming from the other holes in the grid, you've overdone it. The foam is made in several styles; some expand more than others. Find it at Lowes or wherever. Buy one can and play with it to learn how much it expands. When it cures, take a dry chunk of it to the sink and see if it acts like a sponge, which you don't want. Make sure you've got one that doesn't take on water. Good luck!

[Bill Cochrane]

...add a trap instead. Water in the trap will prevent the cold air from draining out, and you'll still have the drain.

More important for ice box users than refrigeration; in the latter case, a plug might be appropriate.

[barfwinkle]

you can put a loop in the drain hose in such a manner that the top of the loop is above the bottom of the ice box.

fair winds from a VERY pleasant (read north winds and cold front) Oklahoma

[Boyd]

Hi All:

I will take the risk of overworking this subject only because convective flow is such a major source of heat gain.

A trap wont work at all if there is no water in it. Unless you put a quantity of water in it on a regular basis to make up for surprisingly fast evaporation then its just a hole in the bottom of your frige. I keep a sink drain plug in mine unless I am flushing out the box.

My box has some kind of traped drain that isnt like anything I have ever seen before. Since it has NSF stamped on it I assume its an ice machine drain. Despite its sophisticated design, both the drain piping and the drain itself sweat considerably due to the cold water contained in the trap. My trap actually froze up a couple of times. Water and ice are a very poor insulators. I finally had to build a surround out of blue foam and completely encase the trap and hose to cure the problem.

A sure sign that your lid gasket is not working is condensation all around the lid.

Boyd
s/v Tern
CD 30 MkII
Fort Lauderdale, Fla.

[Troy Scott]

Boyd,

I removed the same "trap" from my icebox and installed a drain with a plug. I know a trap could work, but I'm using refrigeration, so there shouldn't be enough water to fill a trap. Plus, I don't like the idea of standing water.

For the lid gasket, I'll probably use a thin bulb seal. This type is the most versatile for uneven mating surfaces.

[Neil Gordon]

I just put one of those Rubbermaid circle thingies over the drain. It's not just the cold air going down the drain... you lose lots of cold by draining melt water, as well.

A trap will also capture the inevitable bits of debris that go down the drain, leading to an eventual clog. (There's not much pressure to flush them through the trap.) I'd prefer they just fall to the bilge with the melt water when I drain the box.