Building a Proper Marine Refrigerator and Freezer

Just kidding, what did you think I knew about refrigeration? I'll tell you what I do know, marine fridges are expensive, and they use a lot of power, which is expensive, they take up an incredible amount of space, and you can't put much in them, did I mention they were expensive!

I was going to wait until it was installed and working, but there are so many photos that I though I would update the progress, then do a part 18 later on down the road.

Back in April I made some posts that had the beginnings of the fridge, April 15 being the big one. Since then the project has changed so many times that I can't even remember why all the changes happened. One thing I noticed in that original post was that I intended to gelcoat the inside of the box over an epoxy layup. Back then I believed that that was possible, and now I know that theoretically it works, but in practice its better to paint epoxy. Some of the theory from that post is still valid, no matter how many times it re-engineered itself in my head. So the following is more or less a chronological update.

This was the original box. Designed to give me 4 1/2" of insulation all around and to make maximum use of the space available in the boat. Made from 1/4" plywood, and at this stage it only had thickened epoxy fillets in the inside corners.

Then the entire inside of the box got cover in a layer of glass and epoxy after I epoxy taped the corners.

Then I used thickened epoxy to smooth out all of the rough spots.

Then I cut the bottom off of the box and made it flat across the bottom. Although the original design would fit in the space, and it was maximized to utilize that space, Serena noted that no one was ever going to be able to get at anything in the very bottom of the box. That's when I remembered that humans have a limited reach,  and modified the box accordingly. Unfortunately that means I also lost cold beer room. Ughhh. That will be where her cold beer goes, in theory at least.

The lids. In an effort to keep the box from being too deep, for reasons mentioned above, I only used 3" of insulation in the lids instead of the intended 4 1/2". Also, because of the limited access, and the weight of the lid, I decided to split it in two. The primary lid over the fridge, and the secondary lid over the freezer. The lids interlock and allow for a double seal between one another, just like the fridge box, which I'll show further down. The lids have 3/4" plywood on the top to match the counter height, 1/2" plywood on the sides, and 1/2" on the bottom. Pretty tough for fridge lids, but the theory is that a little weight will help the lids seal better.

The two lids all put together, seams, holes, screws, all filled with thickened epoxy and sanded smooth.

And here is the build of the box interior. There are two sealing lips, one down low and one on the top to help prevent air flow. I put a plexiglass divider between the fridge and freezer. I want to have the freezer cold enough to make ice cubes, but not freeze the beer next door. Theoretically the Nova Kool RT6 unit that I bought is designed to do that, but in a box so small, I was worried that the unit may think I intended to use the whole space as freezer and ruin good beer, so I added the divider, and have enough space that I could insulate the freezer side with 1/2" of foiled insulation. Alternately I could cut holes in the bottom of the plexiglass to allow more cold air to flow if that was required. And just in case, I can remove the divider, if that's what I need to do to make the fridge work the way I want it. However, the secondary excuse for the divider is to hold the slider for the sliding/removable crisper. For putting food in, or something silly like that.

I didn't take any pictures of the painting process, because it was kind of like watching paint dry. But I used Iinterlux's Perfection two part polyurethane. This stuff is nasty. The smell alone will strip paint, it is thin and does not respond well to the brush, or to being put on a vertical surface. But, it you can manage to get enough coats on to cover up the substrate, then you get a finish that is as good as rolled steel. Its impressive stuff, but I will use if very sparingly in the future, just because of how hard it is to work with.

Also here you can see I cut the pieces of insulation at home before going to the boat. The box barely fit down the companionway, so all 16 of the insulation panels had to be glued and tape onto the box while it was in the boat.

The first couple of layers. There is not a lot of space to work with when dealing with something this size in a boat this size. I used PL300 Foam Panel adhesive. I am not really sure how well that is going to hold, but the panels are taped on with tuck tape, and all the seams are taped up as well. I used the PL300 because I didn't want any chance of the glue eating the foam, but also because it has little to no smell. And the tuck tape, designed for house vapor barriers keeps the airflow in check, plus the stuff just doesn't come off. It states right on the roll that this tape is permanent, and it means it. I had some on my garage floor, and I have tried everything short of a sand blaster to get it off, and its still there.

All put together. Jigsaw puzzle, yes, but I numbered the pieces which took some of the guess work out of it.

And here it is mocked up in place. It takes the whole corner of the gallery, with just enough room for the sink on one side and the stove on the other. Also notice I raised the counter top 4" from the original. I don't know what sadist decided that boat counters should be so low, but the way it was, it was a back breaker for anyone over 5' tall.

I may or may not have mentioned it in an earlier post, but somewhere along the way I decided that I had to have 6" of insulation all the way around, or four layers of 1 1/2 code board. However, I ran out of code board after doing only three layers, plus one extra layer on the side where the stove is. I figured that I would try that first, and if there was room left, I would consider buying another sheet. Good call, because there wasn't a 1/4" to spare with the 3 layers. I even had to trim the insulation at the hull and where some plumbing went through. That means there are some weak points in my design, but it'll have to do. On average the box is probably encapsulated with 4 1/2" of insulation, which gives me R27. I could foam in the back, but I think there would be little benefit.

According to the manufacture, with 4" of insulation, I should be able to have fridge of 14 cu.ft., a freezer of 7 cu.ft, or a combo (fridge 8 cu.ft. and freezer 4 cu.ft, at 32 deg C.

Well, I have slightly more insulation, but to err on the side of amateur installation, we'll call it 4", however my entire box is only 2.52 cu.ft.. .6 for the freezer, probably .3 for unusable space, leaving about 1.62 for the fridge. So that's 45L for the fridge, or 63L of total usable space. Compare that to the cooler in your garage and you'll probably notice your cooler is bigger. But I don't have to put ice in there, I hope.

Someone in my yacht club told me that you can't make ice in the tropics on a small boat. Well, I'm sure as hell am going to try.

I built a plywood base for the fridge. There will be bulkheads all around to hold everything in place. Notice the little gap between the front edge of the plywood and the corner of the liner. I poured some water down there, and sure enough, right into the bilge. So this is how water that manages to get into aft starboard quarter, makes it too the bilge. Important to leave that open. Also, its hard to tell, but as before I put a layer of 1/2" foam between the plywood edge and the hull. This piece will not be glassed in, but the bulkhead on the aft side of it will hold the stove, and that will be. Still, I want to make sure there is some room for the hull to flex if it needs to. Hard spots are apparently bad.

And the fridge is in place.

I couldn't go any further because I forgot the drawings for the galley at home, or so I thought. On the way home I realized that they were in the passenger seat beside me.

I was tired....