Refrigeration- Making it Better

[robert sailor]

Where do you get off with Aerogel being so fragile because it isn't. I built our rebuilt fridge using Aerogel and while it had some different challenges fragile was not one of them.

[skipmac]

Originally Posted by nwdiver

I used blue styro and fibreglass/epoxy.

The box was very uniform in dimensions so I carefully cut the board and beveled the edges to fit the bottom and the 4 sides, dry fit and shaved the edges until all was happy I pulled them out and put 1 layer roving and 1 layer of cloth on each panel using a nice flat bench to within 1 inch of the edge of the bevel about 2 hours work, the next day installed the finished panels and using 3 inch cloth stripes sealed the sucker up now I have the original 2 inch and the added 1.5 inch of insulation and a slightly smaller frig, all with the same compressor and cold plate I run run about 1/3 the time they did before the added insulation. I actually pulled the cold plate and compressor to replace them but on the bench they worked fine, so I realized IT WAS THE INSULATION.

First, completely agree. Unless your fridge has been upgraded, it's ALWAYS the insulation.

So a couple of questions. I assume you used epoxy resin or did you use something else? Even though I was pretty sure before hand I did test a polystyrene panel with epoxy, polyester resin and 5200 to see how it reacted. Epoxy and 5200 were fine but the poly resin melted the foam.

The other question. One reason I used the prefab FRP panels was because they already had a nice smooth surface. So how did you get a smooth finish on the glass cloth? I assume you started with a light weight, fine weave cloth but seems like it would take a lot of work, filling and sanding to cover the weave pattern.

[hellosailor]

"First, avoid the spray foam in general since it will absorb water over time. "

Skip, that's a myth. The truth is that there are open-cell foams, which will absorb water, and closed-cell foams, which simply won't. These days it is fairly simple to call the manufacturer and make sure you're using a closed-cell foam.

The higher the expansion rate, the more likely that the gas bubbles will link up and make it open-cell, AFAIK. So if someone is using high-expansion foam because they think that will insulate better...maybe they're just looking at the wrong criteria.

[Tia Bu]

I used the Home Depot FRP panels as discussed above over the Owens Corning pink foam boards from Home Depot. I also found 5200 to be best for laminating it all together.

To seal the joints between the panels, I used West System Epoxy with the microballoon fairing filler (I forget exactly which number it was). I also taped over the joints with fiberglass tape. The result appears to be a very solid, watertight installation. I'm actually using the thing as an icebox, not a refrigerator, so I'm regularly filling it with up to 80 pounds of ice and lots of groceries and drinks.

[nwdiver]

Originally Posted by skipmac

First, completely agree. Unless your fridge has been upgraded, it's ALWAYS the insulation.

So a couple of questions. I assume you used epoxy resin or did you use something else? Even though I was pretty sure before hand I did test a polystyrene panel with epoxy, polyester resin and 5200 to see how it reacted. Epoxy and 5200 were fine but the poly resin melted the foam.

The other question. One reason I used the prefab FRP panels was because they already had a nice smooth surface. So how did you get a smooth finish on the glass cloth? I assume you started with a light weight, fine weave cloth but seems like it would take a lot of work, filling and sanding to cover the weave pattern.

........ yes I only every use epoxy these days for anything........ the epoxy levelled itself on the very level bench and it was fine cloth over a layer of roving and was just epoxy painted once complete, having it on a flat surface was the only way I could do it. I tried on the galley table for one panel that I needed to replace... I then moved the project off the boat saved time and it went well..... this was after helping a friend do his glass work inside his icebox which was a very odd shape, which he could have made a bit smaller and done the work out of the box........

[vRUN]

Originally Posted by skipmac

... I just tried to check their web site and could not connect so wonder if they are still in business?

AFAIK they are selling direct and through suppliers
(don't know your location but as usual) Google is your friend
Barrier Ultra-R - Google Search

pacificseabreeze use it in their (marine) product and sell it:
Price List - Glacier Bay's BARRIER Superinsulation vacuum insulation panels.

I believe a lot of (internal industrial) use has been delayed after some failures
- even Ultra-R is (somewhat) brittle and (definitely) pricey.

[vRUN]

Originally Posted by robert sailor

Where do you get off with Aerogel being so fragile because it isn't. I built our rebuilt fridge using Aerogel and while it had some different challenges fragile was not one of them.

Manufacturer ?
Data ?

[skipmac]

Originally Posted by hellosailor

"First, avoid the spray foam in general since it will absorb water over time. "

Skip, that's a myth. The truth is that there are open-cell foams, which will absorb water, and closed-cell foams, which simply won't. These days it is fairly simple to call the manufacturer and make sure you're using a closed-cell foam.

The higher the expansion rate, the more likely that the gas bubbles will link up and make it open-cell, AFAIK. So if someone is using high-expansion foam because they think that will insulate better...maybe they're just looking at the wrong criteria.

Actually I do believe you are correct. I was basing my, sort of generic statement on dimly remembered information from Mr Kollman about certain types of spray on foam. In fact when I pulled my 25 year old box out the spray on foam around the outside was dry as a bone, to the point of powdery when I took it off. Problem was it was 2" thick max and most places less, some none at all.

Since it wasn't clear to me which brands, types or versions were closed or open cell I was reluctant. Also after testing a few types I had serious concerns about the expansion and resulting pressure on the structure as well as problems curing in a sealed area, so I went with the expanded polystyrene which I felt confident would work.

The curing problem was interesting. I made several test panels using different grades of Dow Great Stuff. A few days later when I pulled them apart to test the strength of the panel I found only the outer 3-4" around the circumference cured and the middle a messy goo with no cell structure at all. Dow tech support informed me that the foam needed moisture to cure so I make more panels but misted the wet foam with water before squeezing the panels together. Pulled those apart a day later and they were completely cured with good cell structure.

Richard Kollman recommends polyurethane sheets for insulation but I wasn't able to find anything about this during my brief research into that option.

[Roy M]

Nanopore is located in New Mexico. They were the providers of VIPs to Glacier Bay. There is a $1000 minimum order, so if you are building a small box, get a friend to share the expenses. My reefer box is about 6.5 cubic feet, requiring about $300 worth of the $1000 that I sent Nanopore. I will be building a freezer after this project, requiring about the same amount, leaving me with a balance in their account that I will use when I build a box for someone else.

The material is wonderful. It comes as stiff 1" panels sealed in a reflective mylar sheath and HEAVILY protected for shipping. I placed mine between 1" foil faced polyurethane from Home Depot, and everything protected by epoxy-coated 1/4" birch ply casings.

If Aerogel is such great stuff, I would expect NASA to have selected it instead of the VIPs for the space station. Not the case, though. You get what you pay for.

Nano pore can be reached at (505) 224-9373. I sent them paper templates of the styrofoam panels I used when designing my box. RParts wouldn't accept paper templates because the Chinese supplier couldn't handle them accurately. Nanopore fabricates its panels in-house at their facility in New Mexico. They are easy to work with and provide good advice.

You will find lots of folks with theoretical knowledge or "common sense" experiences on this forum. You'll find people who have little experience, those with agendas, and those who actually work with these materials. Good luck with your choice of materials, build your box carefully, and don't be afraid to spend money where it is warranted.

[Cheechako]

Having the best insulation is definitely a great goal. I think one has to keep in mind what the overall gain for $ spent will be. Here's a good example. My Passport 47 had two cold spaces; a large freezer cooled by 1/2 hp motor and cold plates and a small, probably less than two cubic feet refrigerator in the middle of the salon table. All we ever used was the smal refrig (it had the little freezer evaporator in it also). I reinsulated that small space with the rigid metal vacuum panels so highly touted at the time. What a bitch it was to do that. In the end, we seemed to run the engine the same amount of time to recharge every day as we did before. Was there a gain? Very little if any. Maybe the gain was the food stayed colder longer... not sure...

[Celestialsailor]

Originally Posted by skipmac

Sorry, I think I'm confused (too easily done these days).

Certainly for structure, hardness and impact resistance the sheets of FRP, but what do you put behind the FRP for insulation, R-value?

Are we talking about the same FRP sheets? I bought mine at Home Depot, white with one side textured the other smooth, about 1/8" thick. Then I glued the FRP sheets to the blue foam board with the FRP as the exposed surface inside my refer box. So I have the strength and water proof (water resistant?) FRP covering for structure and the foam under for R-value.

So do you know of some other kind FRP sheet that also insulates?

So are we talking apples and grapefruit?

What you described is exactly what I meant and my friend did.

[skipmac]

Originally Posted by Celestialsailor

What you described is exactly what I meant and my friend did.

PS

Like your new avatar but it does make me jealous.

[skipmac]

Originally Posted by Cheechako

Having the best insulation is definitely a great goal. I think one has to keep in mind what the overall gain for $ spent will be.

For better or worse this is always part of my decision making process. If the final result is perhaps not equal but at least good and close, I generally go with the solution that will give me the most bang for the buck.

Another concern about vacuum panels, what happens if (when?) they lose vacuum? I seem to recall reading some comments about that problem in the past and noticed that Nanopore's website even mentions "lifetime requirements of the customer" which leads me to believe that they do have a finite lifetime. However I could find no mention of what that might be. Anyone have any information or data from Nanopore on that issue?

For me, the risk of even one panel losing vacuum and the resulting drop in R-value to almost zero is a major concern. Redoing the insulation in my fridge would involve major destruction and reconstruction and I do not want to go there. Already have enough new things to do on the list without adding redos.

[Celestialsailor]

Originally Posted by skipmac

PS

Like your new avatar but it does make me jealous.

Then get it in gear and join the fun!
I don't know if you ever read my thread... http://www.cruisersforum.com/forums/...-up-26626.html
I've tried to do this a few times. It's just my turn now I guess.
Back to Refers...While I'm not where it is real hot...yet. My refer seems to still run for 6 minutes, every 25 minutes. As it did the day i turned it on.

[skipmac]

Originally Posted by Celestialsailor

Then get it in gear and join the fun!

I am doing my best but you know how it goes, stuff happens including the job thing. Also had some family issues I had to be around to deal with that have been eating into my "get the boat ready" time but that's the kind of thing you can't shirk.

I could bail on the job but wife wants to get her 30 years in with the state to qualify for the full pension so I'll hang in another year and a half until she's ready to go.

Originally Posted by Celestialsailor

url]http://www.cruisersforum.com/forums/f108/never-give-up-26626.html[/url]

Don't know if I have but will now.

Originally Posted by Celestialsailor

I've tried to do this a few times. It's just my turn now I guess.

Well at least I can say that I already took one turn but want a second helping. Managed to be a boat bum for several years when I was young and foolish. Mostly did it on the supercheap. Cruising on $500/month? That's luxury. I did a lot of months on $50/month.

Originally Posted by Celestialsailor

Back to Refers...While I'm not where it is real hot...yet. My refer seems to still run for 6 minutes, every 25 minutes. As it did the day i turned it on.

Just finished my box and installed the hardware a few weeks back so haven't timed the on/off cycles. Since I'm one the hard (in the woods) I didn't run it but a few days to test the installation. I did check the battery monitor and once the box was cooled down it seemed to be burning +/- 50 amp hours/day. That's Florida in August with daytime temps in the mid 80s to mid 90s. All in all, I'm pretty happy with how it's working.

One thing I did that so far seems to be working was to install the compressor unit under the floor forward of the mast step. A dead spot with no other use but dry, low in the boat so cool and enough air flow to avoid heat buildup.