Insulating round cooler lid wth spray foam

[Komodo]

Thought I'd pass along my experience since searches pulled up some evidence and references but nothing conclusive.

I've got a 5 gallon round Rubbermaid cooler mash tun, but I imagine this would apply to most any cooler lid. The round ones specifically though. First I tried drilling several holes the size of the spray foam tube around the side of the lid. (brand new can, shaken thoroughly) When you spray the foam in it, it seems to be shooting in there fine, and you can even see the foam expanding out of the holes....but, it's a lie!!! Through some research i found that the foam needs moist air to expand and does nothing inside the lid but create a pile of wet goo. NASTY, ungodly, sticky, wet goo. So, I decided to open it up with the intent of seeing what happened and then filling it and putting it back together.

I carefully sliced the top of the lid off, just under he top rounded edge all the way around the lid with my bandsaw. I held the top against a fence and slowly rotated it. Like hot butter really, no problem. You could probably easily do it with a hand saw. Once removed, you could see the foam did NOTHING. Don't think you have partial foam areas, and it's good enough. You got nothin. First I tried wiping out the bulk of the goo with paper towels, and got 80% of it out. The rest started to turn opaque yellow and expanded slightly!? So, I waited for awhile for that to dry then sprayed foam into both halves, filling them up. Later, I'll shave them flat and somehow glue them together, and use aluminum tape around the edge/seam and that should do it. Super insulated lid and peace of mind. Maybe you don't have to totally remove the top, but if you are just spraying in holes, you are just making a mess.

 

[Stevo2569]

Pics?

 

[starrfish]

Interesting... glad I didn't get around to doing that yet. my recent brews have been in the warm weather so temp loss wasn't an issue.

Glad I saved the old sleeping bag I used on my 5gal bucket mash tun.

Hollow top on 10gal Rubbermaid seems like a weak link to me too.

 

[Rob_B]

Two things I can come up with right now. The first is their FAQ page for Great Stuff Foam says it may not bond to some polyethylene and that HDPE used in coolers is a polyethylene plastic. That doesn't say it won't cure and hold in a form. The other thought is that since it's a moisture cured product you could perhaps drill several large holes in a new lid and lightly mist the inside to kick the reaction. Then easily trim excess foam.

http://greatstuff.dow.com/faq/

 

[Komodo]

I didn't shoot pics of the mess when I opened it, but I should have. Just trust me in that no foam expanded at all, until it came out the side holes.

I'll see if I can snap a couple of the lids tomorrow when I shave them and somehow put them together again. Any ideas? Liquid nails? Some JB Weld? What sticks foam to foam? The tape around the edge is just to seal it and looks, although it would likely be strong enough as is.

Rob- i considered exactly that. I was thinking of cutting much larger holes, say 1" or bigger, also considered cutting off larger sections like the triangle areas on the top. In the end I thought F-it, just cut it off so I can clean it out and know its filled. Putting it back together shouldn't be hard since the lid doesn't need to be super sturdy, just hold together. Actually, I can fudge a little and have the foam thicker than just a filled lid.

 

[Stevo2569]

I didn't shoot pics of the mess when I opened it, but I should have. Just trust me in that no foam expanded at all, until it came out the side holes.

I'll see if I can snap a couple of the lids tomorrow when I shave them and somehow put them together again. Any ideas? Liquid nails? Some JB Weld? What sticks foam to foam? The tape around the edge is just to seal it and looks, although it would likely be strong enough as is.

You could probably shoot some more goo on it then press together. I'm wondering if it didn't expand cause of lack of time. I sprayed the inside of mine and it expanded out all the breather holes. As for bonding to cooler lids, there is still yellow on my lid in a few spots after almost 40 batches through it.

 

[kh54s10]

Just had a thought, what about drilling a bit of a larger hole and filling it with bean bag foam beans?. I think I will try that. Now to find the beans. I had a bean bag chair in the 70's. Long gone.

 

[Komodo]

You could probably shoot some more goo on it then press together. I'm wondering if it didn't expand cause of lack of time. I sprayed the inside of mine and it expanded out all the breather holes. As for bonding to cooler lids, there is still yellow on my lid in a few spots after almost 40 batches through it.

When i sprayed mine it also expanded out of the holes . . .i had 4 holes, about 1/8th inch each. When i opened it, you could see the expanded foam just on the outside of each hole, and liquid inside. Like it was still in the can.

 

[kh54s10]

More holes, spray a little in and let it expand, then spray a little more. Again and again until full?

 

[Zamial]

While this is a very interesting write up, In my experiences the biggest cause of heat loss is head space (between the top of the mash and the lid, more space= more/faster heat loss).

In an uninsulated keggle with a glass lid that seals up effectivly I can experience a loss of 1F to 4F in 60 minutes. The only variable is the head space. (Yes, I have experienced a heat loss of 1F for 90min in my keggle MLT!) In my round rubbermaid coolers I get the EXACT same results it is ALWAYS the head space that is the variable.

The above has lead me to believe there is a right size MLT for the mash. YMMV but I will guess not all that much...

 

[Stevo2569]

When i sprayed mine it also expanded out of the holes . . .i had 4 holes, about 1/8th inch each. When i opened it, you could see the expanded foam just on the outside of each hole, and liquid inside. Like it was still in the can.

Although you have me thinking now, I'm not going to dissect my cooler lid to find out. I lose maybe 2-3 degrees in an hour so I'm fine with that. But one day I'll retire it for something I'm sure, then well find out.

 

[Rob_B]

I'll see if I can snap a couple of the lids tomorrow when I shave them and somehow put them together again. Any ideas? Liquid nails? Some JB Weld? What sticks foam to foam? The tape around the edge is just to seal it and looks, although it would likely be strong enough as is.
QUOTE]

You could try Gorilla Glue, it's another type of low rise foam with a much lower expansion rate. It's also moisture cured. I would take your two halves after being trimmed to fit rub lightly with a damp rag and put a few small beads of the Gorilla Glue. Probably use a circular pattern starting in the middle working your way out to the edge. Then clamp it together for a couple hours or so.

I think the tape around the edge is a good idea, the foam is not UV stable and as it degrades it can get brittle and powdery over time. But that probably would take a very long time since you wouldn't store it outside.

 

[Komodo]

Rob- of course, great idea. I don't usuallu use Gorilla glue cause its so sticky and nasty, very similar to what the liquid foam is like.
I'll report back later with results.

 

[mavrick1903]

Spray foam and polyurethane glue (gorilla glue, titebond also makes one) are basically the same, just a different delivery method. Disclaimer: I'm not a chemist, just have experience with all mentioned. They all smell, and act the same. Moisture helps them cure.

 

[JonM]

I did this a while ago (complete with the mess) and now wish I hadn't bothered.

I recently cut out some discs of 3/4 inch styrofoam with the same diameter as the inside of the tun. I put them into a heat-resistant crockpot liner and rest them directly on top of the mash. It works a helluva lot better than filling the lid with foam.

 

[Misplaced_Canuck]

Why not fill the lid with packing peanuts? They are styrofoam after all...

M_C

 

[BBBF]

This all sounds like way too much work. Just put a blanket on top of your cooler.

 

[phoenixs4r]

I actually cut a hole large enough in my lid to house the neck of my carboy. This helped me with 3 things:

Insulate the cooler lid properly.

Throw a fermenting carboy in there with ice water before I had a fermentation fridge. This was cool because you can drain the old water easily from the bottom and add to the top. You can get really fancy and add a pump to recirculate water from a fridge near by or do what I did and picked up a fridge for free. Lol.

Also will be constructing a PVC tower to slip inside the hole in the lid so when I bring a keg to my companies Xmas party I don't have to bring the hole fridge.

I keep a piece of insulation board I WAS gonna build a fermentation chamber out of with the lid so when I mash, I plug the lid and usually don't lose any heat over an hour on a nice warm day.

 

[Brewfat]

I did this a while ago (complete with the mess) and now wish I hadn't bothered.

I recently cut out some discs of 3/4 inch styrofoam with the same diameter as the inside of the tun. I put them into a heat-resistant crockpot liner and rest them directly on top of the mash. It works a helluva lot better than filling the lid with foam.

This, although I use 2" foam. I have never lost a degree.

 

[Komodo]

Followup.

After first usage, where i probably only filled the MT 2/3rd of the way, I had temp losses in the 2-3 degrees in 45 mins. I don't regret doing it, but will create the disc that sits on the mash for when the MT is not totally filled. From what I've read, I pretty much expected this. Most heat loss happens because of headspace. Btw, the MT was preheated.

 

[CanadianQuaffer]

this all sounds like way too much work. Just put a blanket on top of your cooler.

+1