Insulating an ice box

[Stephen K]

I want to improve the insuating qualities of my ice box. I would rate the current condition "poorr". Of course on the C-30's, we have the dang Universal diesel inside the salon and heat from that beast flows through the cabinetry to areas around with the ice box.

What do you all recommend to improve the insulation? The 1 or 2 inch pink foam board sold at home imorovement stores or the insulating stuff in a can? Any other ideas? I have decent access to 3 sides of the ice box and the bottom piece.

 

[Ross]

I have four inches of foam onsulation in my ice box on the engine side I used foill faced urethane for the rest and the top I used the extruded pink or blue foam. I filled all of the joints and gaps with the canned foam "Great Stuff". It will keep cold for a week in the summertime on forty pounds of ice in half gallon bottles.

 

[RAD]

I took apart as much as I could all around my ice box and used 2" blue foam,1" foam and great stuff every where else and it made a great improvement,the only part I never did was the top cause I have not figured out how to do it and be durable

 

[Joe]

You might try perusing the various Catalina owner organization websites... look for the project pages and there will probably be an icebox insulation article... The C30 and C27 sites are the most likely... If my memory serves me right, the common way is to line the inside of the box with 1 inch sheets, then follow Ross' example for the outside areas. Also the top lid could be modified with a sheet of insulation and a rubber air seal around its perimeter.

 

[RichH]

Consider an 'aerogel'

Example: http://thermablok.com/

 

[sailaway78]

If you can get to it

If you can get to it, put a layer of the reflective foil insulation on the outside of the box around any area you can. This stuff comes in a roll, is reasonably priced, and looks like tin foil bubble wrap.

 

[themadscientist]

I use their products on my cars.
http://www.thermotec.com/products/category/2/heat-and-sound-barriers.html

If you have the space to line the engine box with radiant heat reflective barrier mat that should help a lot. I would monitor the temperature in there though. It might get awfully hot in there if the heat cannot bleed out as it used to and cause engine problems.

 

[Ross]

I repaired my freezer door at home with three plies of 1/2 inch R-Max foil faced insulation. That has been very satisfactory. The engine room should have free air flow either to the outside or to the cabin.

 

[AXEL]

What year is your C30? Mine is a ‘77. I insulated with the thickest pink foam I could fit. I filled in with foam in a can where I could not reach. Also, very important, I glued pink foam to the top (inside) and built a second set of freezer covers that fit under the original. The original covers on the '77 were just wood about 1 inch thick. I also use a foil cover inside the box which I made from those emergency blankets you'll find at West Marine. I folded it over a couple of times and shaped it match the shape of the freezer. I used duct tape to hold the edges together. This works very well when the freezer is not filled all the way to the top. It reduces the area the ice needs to keep cold and helps insulate when the box is opened. I cruised last year for 2 weeks and at the end of the trip I still has a piece of the original ice block left.

 

[Ross]

Keeping the air leaks to a minimum is vital. Condensing moisture from the air requires 7 pounds of ice for each pound of condensate.

 

[kloudie1]

Exactly, Ross ! The other thing is that the water droplets that collect then conduct heat better than the insulation and causes more ice loss .. ESSENTIAL to seal the insulation system from air circulation.

 

[Ross]

The drain was the culprit on mine. I don't have any melt water so the drain exists only for cleaning. I stuffed a wad of paper towel into it. that way it can drip but no air gets in.

 

[Stephen K]

What year is your C30? Mine is a ‘77. I insulated with the thickest pink foam I could fit. I filled in with foam in a can where I could not reach.

Axel, did you use the pink foam inside the ice box or around the outside?
By the way, my C30 is a 1992 MKII.

 

[Stephen K]

If you can get to it, put a layer of the reflective foil insulation on the outside of the box around any area you can. This stuff comes in a roll, is reasonably priced, and looks like tin foil bubble wrap.

I added the "foil bubble wrap" about a year ago. I was able to apply it to 3 sides and the bottom (all of this is on the "outside" skin of the icebox)...I could not reach the side that runs along the port side of the boat. It may have helped some, but not a lot. I think using a loose piece of this (inside the ice box and on top of my items) would help like a blanket and minimize air intrusion.

Can or should I add the "pink board" to the inside of the icebox as a liner? Wouldn't it get wet and possibly mildew when it dries out?

Also, I'm not clear on the bottom drain. I have mine plugged with a rubber stopper to keep air out, but I accumulate water from all the melting ice. I drain this at the end of my trip with the galley foot pump. If I stuff a paper towel in the hole, I'm afraid it will get pulled into the drain hose and clog it.

 

[Ross]

If you have melt water in the box let it drain into a bucket to cool your beverages. I freeze water in half gallon plastic bottles and use the melt water as potable water for drinking and cooking. I also use 20 ounce soda bottles for freezing water for ice. I covered the foam insulation with very light fiberglass cloth and epoxy.

 

[BobM]

One thing I do that seemed to help a lot is to keep a layer of bubble wrap inside the ice box on top of the food. It really seems to extend the life of the ice.

 

[AXEL]

Axel, did you use the pink foam inside the ice box or around the outside?
By the way, my C30 is a 1992 MKII.

I used the pink foam outside and inside as well. For the inside I made a paper template of the top of the box, then cut the foam and used RTV to glue it up there. I used duct tape to hold it in place. The top of the box is just as important as the sides and bottom.

If you have a drain hose you should coil it in a single loop. As long as it remains below the box it will maintain a "slug" of water in the loop that will prevent heat from entering the box.

 

[Stephen K]

I don't have a loop in my drain hose, but will make that change...excellent point.

I'm also going to try the pink foam on the inside.....Many thanks to all for the replies and information.

 

[woodster]

One thing I do that seemed to help a lot is to keep a layer of bubble wrap inside the ice box on top of the food. It really seems to extend the life of the ice.

you can also put rock salt on the ice and make it last longer as well...just like we did on the old hand crank ice cream freezers when i was a kid.....

regards

woody

 

[Ross]

you can also put rock salt on the ice and make it last longer as well...just like we did on the old hand crank ice cream freezers when i was a kid.....

regards

woody

Salt reduces the melting temperature of ice. That is why you could freeze ice cream. The latent heat of fusion of water is about 140 btu's per pound. That value is fixed. A salt and ice mixture can be gotten as cold as zero degrees F. That is how Zero on the Fahrenheit theromometer was derived, boiling is 212 degrees at sea level.