Re-insulating My Refrig. Box the Hard Way.

[jhulmer]

PROJECT POST: #6

With most of the void filled with pour in place 3lb foam, I needed to fill the last of the voids completely.

I have used foam in a can before for injecting into a sealed cavity and it was a disaster. Foam in a can works great for filling open voids but if it is deprived of air, like it is in the can, it does not react and foam up. In my case when I opened the sealed cavity on that previous project I had a gooey mess. So I want make that mistake here.

Instead I will use a method that I found works well if you get your ducks in a row and work fast. I use quart plastic freezer bags that have the little pull zipper on them. You need a piece of 1/2" tubing and some masking tape. The tubing can't be any longer than 6" or any smaller then 1/2" or it will explode before you get the contents out. Yup! happened to me! Cut the corner out of the bottom of the bag so that you have to force the tube through the hole from the inside. Then tape the seam on the outside. (see picture)

This makes an injector for the liquid foam. I drilled a hole in a couple of the areas that need to be filled and inserted the tubing into a hole and mixed up about 18 to 20 oz. of foam. I Quickly Poured it into the bag, that is already inserted in the hole, quickly zipped it closed and squeezed as much of the contents as possible into the void. This is another place where you should buy some beer and invite a friend over to help.
It took several of the these to finish the areas that did not fill completely from the big pours and although wastes some foam, works well.

Now the only area that needs to be filled is the first quadrant that we used as a dam. I chose this one as my starting point because it has the 1-1/2" hole at the top for the refrigeration line set. I knew I could use it to finish the pour. I removed the plastic sheet that I was between the foam and liner that allowed me to remove that section of the liner multiple times, and replace the liner section and secured with the wood blocks.

I made a funnel out of rolled up poster board (single ply cardboard) and inserted it in the hole. I figured this area was going to take 3 qts of foam and it all need to be poured at the same time. Time to call in some help. Pre pour 3 quart measuring cups with part B and then pour in Part A, mix vigorously for 20 seconds and pour in the funnel. This must be smooth quick action and the liquid foam must be at 70 deg F.

I had some areas up under the counter top that need foam as well and I failed to take pictures of this operation. I was simple enough, although pouring foam up hill generally doesn't work. I wrapped a piece of cardboard with poly plastic and taped it under the lip of the area I wanted to fill with masking tape. Using the injector bag and filled that area with two doses of foam. This foam I didn't glass over, the ploy covered cardboard made a nice smooth finish so I just gelcoated over it and its good.

FOAM DONE! After the foam had a day to cure it did a percussion test by tapping all over the liner listening for any hollow sounds and much to my relief it is solid.

As you may have notice in the pictures, despite my best efforts, I did get some bulging of the walls of the liner. In hindsight I should have installed some cross boards to help prevent this. But all in all it doesn't bother me and its just thicker insulation. However, it does add a little difficulty to making the divider between freezer and frig, but not that big a deal.

I removed all the wood blocks and the tape and plastic. I cleaned up all the mess and set about sanding the seams. I used 2" wide 12 oz fiberglass cloth tape to seal the seams. So, I need to grinded the seams 2" wide and bevel them down about 3/32" to receive the tape. The liner sections are well secured by the foam and the glass tape is mainly just sealing the seams.

I mixed up some polyester resin (no wax) and laid up two layers of tape on every seam. Once cured I sanded the seams flush and smooth. I used polyester fairing compound and filled all the low areas. Once that had cured the next day I sanded the whole liner and rolled on four coats of white gelcoat. I did this over two days, even with a good respirator and carbon filters it's hard to stay in the boat with this stuff. The last coat of gelcoat I added the wax to finish the cure.

I was going to sand and polish the gelcoat after it cured but decided I liked the slightly textured finish the foam roller left, and a lot less work.

BOX DONE!

Now I need to make a divider wall and add insulation to the lids. I am currently finishing these items and will post my progress tomorrow.

Thanks again for following,
Jim

[john61ct]

Great job, excellent report, thanks!

[RaymondR]

Originally Posted by john61ct

Great job, excellent report, thanks!

[jhulmer]

PROJECT POST: #7

DIVIDER WALL AND TOP DOORS.

I am currently finishing the divider wall between the freezer and refrigerator compartments and adding insulation to the doors.

I am using XPS board (blue, pink board) to fabricate the divider. I bought a 4'W x 8'L x 1" thick board and glued two pieces together to make the divider.

I first made a template out of thick cardboard. I trimmed this about 1/8" undersize on all edges to allow for fiberglassing over the foam. (see picture) I will be finishing the divider with white gelcoat.

I will be installing a circulating fan through a 3-1/2" dia hole that is supplied by Coldeh, to push air from the refrigerator compartment into the freezer compartment. On the opposite side of the divider I will cut and line a 3-1/2" dia return air hole.

The doors needed additional insulation as well, so I cut the bottom panels out to get at the old foam. I removed all the old foam and filled that cavity with some 8lb pour in place foam I need to use. I could have cut sections of XPS and filled this area also.

The metal countertop tends to be a thermal bridge to allow heat into the box. So to mitigate this as much as possible I need to reduce its contact with the inside air of the box.

I decided to add a layer of XPS board to the bottom of the doors that would fill the 1" gap between the bottom of doors and the bottom edge of the countertop. I will then add weather-stripping to the bottom edges of the door to seal off the top.

As I progress, I will have additional posts of the finished door and divider as well as the install of the refrigeration plates.

Hope you find this helpful,
Jim

[skipgundlach]

Nice.

A question, though, as the spillover design seems to have two big holes in it; I can't tell from the pix nor remember from earlier posts the CF here, but...

In consultation with my supplier when I built ours (more vertical compared to width than yours) I was advised to center my fan, blow INTO the reefer, and make a top opening equal in SI to the fan opening. In my case that worked out to a 1" gap at the top.

I have a front-open reefer and top-open freezer. Both have NO/NC reed switches on them. In the freezer, as you would not want to interrupt the compressor, that turns off the circulating fan (smaller than the spillover) and turns on the puck LED. In the reefer, that turns off both the spillover and circulating fans and turns on 3 pucks.

That seems to work well, though your installation intention has me wondering if (I'm not about to redo it!) a bottom gap, and a top fan, might not make a more effective reefer flow - cold in at the top, which sinks, anyway, and into the bottom, which should be coldest, anyway, of the freezer, and, at the same time, make an enhanced air flow inside the freezer (we have an acrylic shelf with 1" holes in it plus space at the brackets both ends)...

We made our doors out of the same material as the sides; being the top, however the top door is only 4" - the front opening one is 6"...

Your drain is a perfect place for cold to get out, btw, though I'm sure you have thought of that. Do you have a valve on it?

[jhulmer]

Originally Posted by skipgundlach

Nice.

A question, though, as the spillover design seems to have two big holes in it; I can't tell from the pix nor remember from earlier posts the CF here, but...

In consultation with my supplier when I built ours (more vertical compared to width than yours) I was advised to center my fan, blow INTO the reefer, and make a top opening equal in SI to the fan opening. In my case that worked out to a 1" gap at the top.

I have a front-open reefer and top-open freezer. Both have NO/NC reed switches on them. In the freezer, as you would not want to interrupt the compressor, that turns off the circulating fan (smaller than the spillover) and turns on the puck LED. In the reefer, that turns off both the spillover and circulating fans and turns on 3 pucks.

That seems to work well, though your installation intention has me wondering if (I'm not about to redo it!) a bottom gap, and a top fan, might not make a more effective reefer flow - cold in at the top, which sinks, anyway, and into the bottom, which should be coldest, anyway, of the freezer, and, at the same time, make an enhanced air flow inside the freezer (we have an acrylic shelf with 1" holes in it plus space at the brackets both ends)...

We made our doors out of the same material as the sides; being the top, however the top door is only 4" - the front opening one is 6"...

Your drain is a perfect place for cold to get out, btw, though I'm sure you have thought of that. Do you have a valve on it?

Skip,
Thanks for the comments. Perhaps John with ColdEh will chime in here.

I have attach a sketch of what John and I have discussed on the divider design. Both holes will be close to the top of the divider. There will be a section of PVC pipe glued in the holes to seal the foam and these holes will be completely open. I will mount a small DC fan inside one of the holes blowing from the refrig into the freezer which will push cold air back into the refrig. The fan will be temperature controlled based on the set temp for the refrig. The freezer temperature will be control by a separate thermometer. This is the design of the ColdEh system.

And as you point out the cold air will fall to the bottom of the refrig and I plan to have a shelf, similar to what you describe, in my refrig as well.

As to the drain, I thought long and hard about taking it out completely, but I like a drain when cleaning, or if you have to use it as an ice box. So, I left in and I have a good lever lock plug for it. I also am considering adding a round poly foam cord to the end of the plug for more insulation. This poly cord is used to push into cracks and crevices in construction to seal them off. A valve will probably work just as well if it is as close as possible to the bottom of the box.

[skipgundlach]

Roger that. Both at the top, however, will promote stagnation below, and keep the top of the freezer warm while not delivering the coldest possible air to the reefer.

I also have two carel electronic thermos. Both were previously at a 2 degree hysteresis mounted on the divider for the freezer, and on the interior wall for the reefer.

Both worked well, but when my frigoboat bit the dust (see other threads in CF) it was replaced with Sea Frost, and a controller which read box temps but controlled on plate temps, 6.5 hysteresis, which results in a box swing more like 10. I'm not thrilled with that but see no other way to make it work in that system.

However, using freezer air for the reefer is how most home frig systems are set, so it should work well. I'd question the both-top placement, though, as above.

I don't recall if you've said - do you also have circulating fans? And, if it's not part of the design, check out the inexpensive NO/NC reed switches for turning off the spillover (and circulating fans, if you have them) and turning on lights when you open the door. Very low current on that fan and lights, so won't require a relay (or a least mine hasn't, and I have a 4" and 2" spillover and circulating fan in the reefer).

[jhulmer]

Originally Posted by skipgundlach

Roger that. Both at the top, however, will promote stagnation below, and keep the top of the freezer warm while not delivering the coldest possible air to the reefer.

I also have two carel electronic thermos. Both were previously at a 2 degree hysteresis mounted on the divider for the freezer, and on the interior wall for the reefer.

Both worked well, but when my frigoboat bit the dust (see other threads in CF) it was replaced with Sea Frost, and a controller which read box temps but controlled on plate temps, 6.5 hysteresis, which results in a box swing more like 10. I'm not thrilled with that but see no other way to make it work in that system.

However, using freezer air for the reefer is how most home frig systems are set, so it should work well. I'd question the both-top placement, though, as above.

I don't recall if you've said - do you also have circulating fans? And, if it's not part of the design, check out the inexpensive NO/NC reed switches for turning off the spillover (and circulating fans, if you have them) and turning on lights when you open the door. Very low current on that fan and lights, so won't require a relay (or a least mine hasn't, and I have a 4" and 2" spillover and circulating fan in the reefer).

Lot of food for thought here. Based on my previous experiences with spillover systems we had a hole lower in the divider with a slide over damper and I thought it worked well. I had originally planned to do it that way again here. I will discuss this again with John.

My current thoughts are to put two 2" holes in the divider one at the top and one close to the bottom. I can include the slide over damper if necessary.

I also like the reed switch idea to control a circulating fan and LED light. I will give that some thought. Easy enough to add.

thanks for the comments,
Jim

[TheOffice]

Great job and great write up

[Typhoon]

Originally Posted by jhulmer

Lot of food for thought here. Based on my previous experiences with spillover systems we had a hole lower in the divider with a slide over damper and I thought it worked well. I had originally planned to do it that way again here. I will discuss this again with John.

My current thoughts are to put two 2" holes in the divider one at the top and one close to the bottom. I can include the slide over damper if necessary.

I also like the reed switch idea to control a circulating fan and LED light. I will give that some thought. Easy enough to add.

thanks for the comments,
Jim

We put both ports at the top for a few reasons , one being circulation , the cold air from the freezer will tumble down in the fridge and the warm air from the fridge will rise , no need for a lift tube. Holes in the bottom get covered with stores and get very dirty and hard to clean . If they work correctly the hole at the bottom will freeze everything in the bottom of the fridge unless you have a lift tube , another thing you have to worry about . It is crucial to circulate the air in the fridge , not so much in the freezer. Once your freezer is full, as most of our small freezers are, the coldest part is at the top , right where the vent is . This has been in my experience and many years of trying different spillover layouts , the best compromise of good cold air flow with out over complication.

Sorry for the late interjection into this thread but this is a very time of year.

With all the great work Jim has done on his box he will have great refrigeration in the tropics.

Regards John
www,coldeh.com

[jhulmer]

Originally Posted by ColdEh Marine

We put both ports at the top for a few reasons , one being circulation , the cold air from the freezer will tumble down in the fridge and the warm air from the fridge will rise , no need for a lift tube. Holes in the bottom get covered with stores and get very dirty and hard to clean . If they work correctly the hole at the bottom will freeze everything in the bottom of the fridge unless you have a lift tube , another thing you have to worry about . It is crucial to circulate the air in the fridge , not so much in the freezer. Once your freezer is full, as most of our small freezers are, the coldest part is at the top , right where the vent is . This has been in my experience and many years of trying different spillover layouts , the best compromise of good cold air flow with out over complication.

Sorry for the late interjection into this thread but this is a very time of year.

With all the great work Jim has done on his box he will have great refrigeration in the tropics.

Regards John
www,coldeh.com

John Thanks for clarifying the spillover design I had forgotten our discussion as to how this was better than what I wanted to do.

I will post more pictures when I complete the doors and install the system.

[sailcrazy]

With a boat almost as old as yours, I'm considering a similar project for both the refer and freezer boxes. Mine are side-by-side, with only counter-top above them, no sink or other infringements, but...they are both built-in and with no access anywhere.Did you consider just drilling a series of small holes in the liner, hogging out the back side, and using spray foam insulation(letting it expand to fill whatever voids there may be) vs your method of cutting out large sections of the liner? Why did you opt for your plan? How will you reinstall the sections of removed liner, and what will you use to cover the existing liner...a layer of fiberglass, or?

[sailcrazy]

Please disregard my post-previous...for some reason my computer did not show pages 2-3 when I read your thread.. Now they are all showing.. Impressive job!

[jhulmer]

Originally Posted by sailcrazy

With a boat almost as old as yours, I'm considering a similar project for both the refer and freezer boxes. Mine are side-by-side, with only counter-top above them, no sink or other infringements, but...they are both built-in and with no access anywhere.Did you consider just drilling a series of small holes in the liner, hogging out the back side, and using spray foam insulation(letting it expand to fill whatever voids there may be) vs your method of cutting out large sections of the liner? Why did you opt for your plan? How will you reinstall the sections of removed liner, and what will you use to cover the existing liner...a layer of fiberglass, or?

Hi Sailcrazy,
thanks for the questions. Read through all my posts, they will answer most of your questions.

I did consider trying, as you suggest, to avoid cutting out the 4 panels but in the end this would have been a waste of time. In my opinion it is better to cutout the sections and get the old foam out. It looses all it's insulation properties over time. In the end you will be much more satisfied with the results. Also, foam in a can is not good for this type of insulation.

By the way, this was a time consuming project but not particularly difficult.
cheers,
Jim

[john61ct]

Yes drilling holes and adding spray foam would not help much.