building a drop in freezer/refrigerator box

[the bookie]

Hello everyone, I just literally threw my norcold DE 0061 over the rail and onto the hard at the yard. The nevercold is gone and I'm left with this predicament of what now? I have looked at the same model and it has horrible reviews and I promised myself I wouldn't go that route again. I'm almost sure I'm going to go with the cool blue as it looks easy enough to assemble and such. I'm currently looking at building my box. I ordered the 2 part pour foam and such but my question is the wood itself. Do I have to seal the wood with clear epoxy or can I just throw 3-4 coats of 2 part epoxy paint on there and call it good. Is that a common practice to use epoxy paint inside a refrigeration box? I also wonder if anyone in the tropics use a non water cooled system like cool blue and has it held up well? I'm currently sailing the mid atlantic waters around NY but will be bringing her south this winter and bringing her back in the spring. She's a 45ft steel ketch and well insulated. I welcome all opinions! Regards

[coopec43]

I was looking at this problem some time ago. I think these are some links I found useful:


https://www.sailmagazine.com/diy/how...ng-your-icebox


https://www.indelwebastomarine.com/u...-your-own-box/


https://uk.boats.com/how-to/efficien...-how-to-guide/

[OzeLouie]

Hi Bookie.. Most important to get he cabinet right as a priority. Here below are a couple of tips but also try to avoid metal linings and vapor seal inner and outer linings before adding insulation. If you have no experience with two mix urethane I suggest doing a few small exploration pours away from the project as this stuff can do some strange things.
Once you have established the dimensions of your cabinet, those interior dimensions and other relevant factors needed can be used to find a heat load, duty cycle and power consumption estimate specific to your project so you can then select refrigeration equipment that is capable in the nominated situation.
Regards water cooling: Air cooling with recycling fresh water combined as required is the ultimate specially in the tropics, but air cooled with adequate through air is fine in most other applications, depends a lot on where the condensing unit is to be located.

I hope this helps:



Add more insulation under and less at the top...

[coopec43]

Don't make the mistake of filling the void between the box and the hull. Air must be able to circulate around the box to get rid of heat coming through the hull. (Right now the sea water temperature in Darwin Harbor is 86°F - (30°C)

[sailortype]

"Don't make the mistake of filling the void between the box and the hull"
Is this a thing..? I have this job ahead of me this Spring and have never heard of leaving a gap between the insulated box and the hull. In addition to the practical difficulties in insulating and leaving such a gap... the space in that area is quite limited and I would have thought filling it with every last ounce of closed cell foam insulation would have been the best method.

[tml]

We built our box without a gap at the hull using the pink foam panels to 8" for an R 40 value. No problems that we have noticed. Using an infared thermometer don't see any temp differential even in full sunlight.
Talk to Cleve at Seafrost, his DC air cooled units have worked for us and many others.
If you have limited wall thickness look at aerogel insulation. We used it to beef up the R value where the cabinetry limited us to four inches or less insulation space. It is expensive but it does work.
We found the insulation in the tropics was likely more important than which refrigeration unit used.
Good luck
Tom

[guyrj33]

Originally Posted by coopec43

Don't make the mistake of filling the void between the box and the hull. Air must be able to circulate around the box to get rid of heat coming through the hull. (Right now the sea water temperature in Darwin Harbor is 86°F - (30°C)

Why would anyone want hot air circulating around the outside of their insulated fridge?
Fill every space possible with foam!

[realem]

I have written on this subject a couple of times. I had an engel drop in that worked great until it didn't. I had cut out the old ice box to put the engel in. The issue with the drop in type is they are not really repairable. My answer was to refrigerate an off the shelf cooler,ie igloo, coleman etc. Already insulated and you can add more, very inexpensive but effective. I ended up with an igloo 60 quart size mainly because it fit the existing hole with minor modification and I could use the existing corian top. I install an evaporator plate and tethered danfoss compressor. Works great, solar panels keep up with it just fine and the batteries stay charged. I cut of the top of the cooler and fabricated a top that worked with the corian that is flush to the galley top.
'Hope this helps

[Scubaseas]

Originally Posted by coopec43

Don't make the mistake of filling the void between the box and the hull. Air must be able to circulate around the box to get rid of heat coming through the hull. (Right now the sea water temperature in Darwin Harbor is 86°F - (30°C)

Huh? Say what? An air gap does have an R value (like 0.16) but no where near as high as foam (3.7 to 6.7 for urethane foam) is. Now a vacuum break......

[Hudson Force]

I converted a 10 cu ft ice box to a 6 cu ft freezer/refrigerator (4+ cu ft frig & 2- cu ft freezer) with the cold plate for my Technautics Cool Blue on the freezer side and a dividing wall with about six adjustable air exchange vents.

I did this in about 1995(?) and it was still serving me well in 2017 when I sold my boat. There might be something better now, but the "cool blue", especially with the very well performing Danfloss compressor was very reliable for almost constant use during 22 years of full time live-aboard cruising.

I did have the unit mounted in my engine room which was sometimes very warm and causing a longer run time to exchange heat. Despite this, with solar, wind and diesel power generation, I never had a significant drain of my 12VDC due to this system.

[Madehn]

be aware- 5200 is called the "devils glue" from recent experience i can tell you that 2 part foam is the devils first cousin-- that stuff gets on everything and sticks like anything- have some acetone already poured and ready to use to get off spilled areas etc while still wet- after that stuff sets up it wont cut it- disposable gloves are a must- sets up VERY quickly and is strongly exothermic.

[j.g.evans]

If you are building the box from the outside in then use ready made foam panels and seal the joints with spray foam. Finish the inside with the white, 1/8", fiberglass, 4x8 panels from Home Depot. If you are using pour in foam then use a little at a time. It expand with a lot of pressure and will distort your box if not careful. I found it coming out of a small hole in a 1/2" bulkhead where I had removed a wood screw. There will be water in the bottom and I don't have any suggestions on sealing it. I used pour in foam around the outside of an existing fiberglass ice box and didn't have to deal with water in the bottom.

[coopec43]

Originally Posted by guyrj33

Why would anyone want hot air circulating around the outside of their insulated fridge?
Fill every space possible with foam!

I don't know where you sail but the conditions would likely be very different between the UK (or Canada) and the tropics. The sea water may even keep the freezer cold in the UK or Canada!

As far as filling the void with insulation it was a refrigeration tradie who has done a lot of work on boats in Darwin said not to do it.

My reasoning is that if the insulation goes out to the hull the heat from the sea water would be conducted through the insulation to the contents of the freezer.

If there is a gap the heat would have to be radiated and that heat can be partially repelled by reflective foil

[coopec43]

Originally Posted by Scubaseas

Huh? Say what? An air gap does have an R value (like 0.16) but no where near as high as foam (3.7 to 6.7 for urethane foam) is. Now a vacuum break......

Would you rather put your hand on a hot-plate of your stove or keep it one inch from it?

It's not rocket science!

[GordMay]

Originally Posted by coopec43

Don't make the mistake of filling the void between the box and the hull. Air must be able to circulate around the box to get rid of heat coming through the hull. (Right now the sea water temperature in Darwin Harbor is 86°F - (30°C)

Coopec may be thinking of a [infra-red] “Radiant Barrier” air gap, to prevent thermal conduction.
This would be an inappropriate misapplication of this technology.