Refer Insulation

[SV THIRD DAY]

Na...it's much more fun to drive the "proper vapor barrier folks" crazy with what works in the real world.

[daletournier]

I didn't know this was so complicated. I'm in the Philippines, limited access to materials relative to the US or Aus. I recently cut my fridge in half using High density Extruded Polystyrene and a pvc type board to line it all. Corked it all with a bathroom silicon then added a Ozefridge eutetic system. Once the plate is frozen the compressor dosent come on for another 12 hours. In fact if I turn it off its still cold 24hrs later and that's in the tropics. I didn't complicate this , just added 2 inches of polystyrene to the walls and filled the bottom half of fridge also. So I'm with Rich, don't get caught up with over analyzing something that is pretty simple.
Cheers Dale.

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[SV THIRD DAY]

You see this quite often in internet discussions, I call it the SOTF (Sliver Of Truth Factoid). In focusing in on the vapor barrier physical properties of “polyester” (to keep the argument technically correct but practically meaningless) as Tera Nova is missing the larger picture.

Sure polyester alone isn’t a true scientific vapor barrier, who doesn’t know that? But the other ½ of the story being left out is, do you ever have just a polyester/fiberglass box and just how good of a vapor barrier is it? Of course Q1 is no, no one’s box is just pure polyester and glass, there is gelcoat on top of it. So quoting the physical properties of polyester scores techy points in a forum, but how useful is that point since I’ve never seen an ice box made out of glass and polyester? They all have the added vapor barrier of gelcoat. So then how good is it and is it good enough? Are we 50% as good? 90% as good? How does that factor into the Cost/Good enough curve? When I've cut into boxes reinsulated using this simple/cheap approach 10/15yrs later and found them still good...what are we arguing about for $200 in materials and a weekend of labor? How many angels can dance on the head of a pin?

What kills insulation…air movement around it that brings moisture and said moisture then condenses and if it gets into the foam it wets it and then ka-bash…the foam is worthless. So that’s where my “crazy” comments comes into play because how much better is an epoxy true vapor barrier than the ice box tub the cruiser has now? Is that degree of improvement worth the work/expense? Not to most people it isn’t.

I shouldn’t be as much of a smart ass as I am…it’s probably not good for “business” as my wife says, but hey, my sense of humor is what it is and it’s taken me this far as a Cruising Bozo. I’m not trying to knock Tera here his box is probably a dream case box and a thing of beauty. I'm trying to point out that when discussing techy things, the one line data points without discussion behind them can cause more harm than good. Every thread about box insulation makes it sound like if you do anything but poured foam, aerogel or VIPs then you are doing it wrong and a screwing up....I call BS on that.

For example, a guy with a classic plastic bath tub ice box. Is he better off adding 1-2” of PolyIso insulation to the inside of his box, covering it with fiberglass board from home depot, caulking the seams and then getting his ass out cruising with a improved box to cut down on power usage at a cost of less than $200. OR do we tell that guy that the only way to go here is to rip out his box and pour closed cell foam, use Vacuum panels, or some other expensive solution that will give him what…how much better a solution? Sure in the ideal world of time/money, rip it all out and do it “right” by NASA standards. Build a new counter top and galley counter while you are at it! But that isn’t what most people have the time/money/stomach for. Adding a few inches of polyiso to the inside of a crap insulated box is sure low hanging fruit to pick and toss at the emperor that has no clothes.

This is also what happens when I'm in the boat yard with projects lined up...I keep looking for something else to do rather than all the prep work for laying a new epoxy/glass true vapor barrier on my deck in preparation for KiwiGrip.

[Matt Johnson]

Don't worry Rich..."Ignore" is set high for that one.

Matt

[Terra Nova]

Originally Posted by SV THIRD DAY

...
Sure polyester alone isn’t a true scientific vapor barrier...
no one’s box is just pure polyester and glass, there is gelcoat on top of it...

More troubling "new" facts for you: gelcoat is polyester and is not a vapor barrier.

Call me crazy, but I have had to rebuild many reefer/freezer boxes built by others who didn't have their facts straight.

[SV THIRD DAY]

Originally Posted by SV THIRD DAY

Na...it's much more fun to drive the "proper vapor barrier folks" crazy with what works in the real world.

...see how fun this is...

Now back to the deck.

[senormechanico]

Originally Posted by Terra Nova

More troubling "new" facts for you: gelcoat is polyester and is not a vapor barrier.

Call me crazy, but I have had to rebuild many reefer/freezer boxes built by others who didn't have their facts straight.

So if that's true, how come when I had the boatyard strip off all my old bottom paint, check the original gelcoat over polyester bottom for water intrusion on my 20 year old boat, they said it was TOTALLY DRY??

Oh yeah, and no blisters at all.

It must be some kind of water repellant thing having to do with (add your favorite conspiracy)

[Terra Nova]

Originally Posted by senormechanico

So if that's true, how come when I had the boatyard strip off all my old bottom paint, check the original gelcoat over polyester bottom for water intrusion on my 20 year old boat, they said it was TOTALLY DRY??...

uh...because the previous owner had the sense to apply an epoxy barrier coat?

[SV THIRD DAY]

Originally Posted by Terra Nova

uh...because the previous owner had the sense to apply an epoxy barrier coat?

So every 30yr old boat has an epoxy bottom...I love this guy, where do I check into the No Reality Hotel and once you check in...can you ever check out?

So how much do you CHARGE for these "proper vapor barrier coat boxes"? And now much "better and longer lasting are they for that extra money? Ah....now we know why the $200 way is no good....

[Badsanta]

A friend added insulation inside the box. But first he drilled holes through the tub walls and used spray foam into the holes. He said most places were solid but there were a few major voids in the old pored in foam. He was glad he checked it. Just info.

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[autumnbreeze27]

I rebuilt my freezer... somebody already had insulated the inside. Tore it all out, rebuilt the whole box, now I'm fighting the damn compressor. Rich got tired of responding to my emails, so now I'm waiting until I have time to work on it some more.

Do yourself a favor, and put in a prefab unit. Sure, it will only utilize half the space as the built in one... but it would be soooooo much less painful.

We also have an Engel that we use when the freezer stops working.

[senormechanico]

Originally Posted by Terra Nova

uh...because the previous owner had the sense to apply an epoxy barrier coat?

Nope.

[Stu Jackson]

Originally Posted by SV THIRD DAY

So every 30yr old boat has an epoxy bottom...I love this guy, where do I check into the No Reality Hotel and once you check in...can you ever check out?

So how much do you CHARGE for these "proper vapor barrier coat boxes"? And now much "better and longer lasting are they for that extra money? Ah....now we know why the $200 way is no good....

I volunteer being a guy with an almost 30 year old boat.

No barrier coat on the bottom.

Boat's still floating, no water ingress.

My fridge box is the same gelcoat.

Real world trumps.

KISS.

Rich is right.

[Marpessa]

Rustoleum has a spray rubberizor that I'm going to test out. Somehow I've got to make an attempt at sealing the foam. I have the tape, I'm going to apply that over the painted edges. Yes there are some nicks in the r-max foil, so I'll apply the tape over them after I spray can on the rustoleum. Seems to be an easy, cost effective solution.

On the topic of vapor locking the cabinet:

My guy said to give lots of drainage so the foam doesn't sit in water inside the void.
Right now there is just the simple old ice box drain that goes in the bilge. It's really not even the low point of the ice box.
So, I drilled some holes to poke around in the bottom of the box.
All the existing foam is wet. I have found a source for dry rot, mold, who know what down there...
This is the original foam insulation from 1979. I'm going to hole saw some access today and dry to suck some of the old stuff out from underneath and get it dry.
Btw, I haven't put ice in this box in years. YeArs!! It's crazy this stuff is still wet, must be water getting in there from outside somehow. I'll be finding out today I hope.

So, it's an interesting question: To seal, or not seal, the new void I'm creating? I can probably get pretty close to air tight. And I guess that assumes that no water ever will leak through any of the frp nor the joints that I fillet up. That also means using a pump mechanism to lift the defrost water out of the hole. Because: I know that if I cut a drain hole in the bottom and there's 6" of foam to travel through someday that drain will start to leak/weep into the foam and once you break the vapor lock, the whole thing becomes a greenhouse.
Yeah, tough stuff here if you want to get it right. Maybe tall kitchen plastic bags and some twist ties is the answer. Bag each foam panel up. Problem there is I can't seal the seams between the panels as well. On that note I plan to fill each gap with a shot of foam as the panel goes in. But the foam spray stuff takes on moisture too! And at the edge of the panel, the weakest point! Maybe I'll just use the tape.
...you really can't win. Stupid boats.

Btw, anybody ever use Reflectix? For anything cooler related?


Glad I got you all jawing on this one it's entertaining; thanks for all the responses on an old thread!


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[crazyoldboatguy]

Water penetration into a 53 y/o hull made of solid laminations covered with a gelcoat is one thing. Water vapor penetrating a gelcoated fridge is another. How long will it take for the penetration to occur?

In those incidents mentioned - and, for that matter, the majority of condensation problems seen in a boat, where does the moisture come from? The inside of the box?

In my understanding, most of that condensation comes from the outside - a poorly insulated fridge with an inadequate exterior vapor barrier allows moisture to penetrate into the insulation - to stay there and wreak havoc. Even the best hydrophobic insulation can be overwhelmed over many years.

Clearly, the inside of the box should be well sealed. Most folks would use epoxy in construction now anyway - I even used 2000e in my box to make sure the water didn't penetrate. But, curiously, when I had the icebox out a number of years ago there was NOT ONE drop of moisture damage on the structures underneath the icebox. And that cooler was made from polyester, not epoxy. And NO gel coat - just paint. And no drain to the bilge. The darn thing sometimes sloshed with an inch of freezing water if you didn't take a sponge to it.