Custom cooler lid fail. Where did I go wrong?

[MMBB]

I am making a portable kegorator out of a 70qt Igloo cube cooler and, inspired by another post and not wanting to hack up the lid, I decided to make a custom lid out of Great Stuff. It went well, at first but then the lid shrunk.

I used the high expansion formula and did it outside in the sun (around 80 degrees yesterday). I drained the cooler and removed the keg and lid after about two hours. The thing was left in my basement over night while I was at work.

I got home this morning and saw this:

Yep. the lid shrunk all around. anywhere from .5" to 2" gap all around.

Where did I go wrong? Should I have left the lid on there for longer? Let it finish curing outside? Should I use the normal (gaps 1" or less) Great Stuff? I am not opposed to trying this again tomorrow.

 

[BBL_Brewer]

Just use the lid that came with the cooler and go have a beer.

 

[Dolomieu]

Why would you have to hack into the lid?

 

[MMBB]

Sorry, I forgot to specify in my original post. Portable kegorator for five gallon cornys. Original post edited. A little too much home brew today!

 

[Dolomieu]

that makes sense then, though the great stuff approach seems odd. I would probably use foam board insulation instead.

 

[MMBB]

In theory, this works great. Put keg in the cooler, fill cooler with water up to the lever that you'd like to foam to start, spray in foam. The lid, before it shrank, fit the cooler like a glove and the foam is "semi-waterproof", sandable, and paintable. I just don't know why it shrunk so much. I may do a two prong approach. Fill the cooler to the desired level again and re-seal the old lid and once that is done I'll do an entirely new lid and let it sit for the entire eight hour curing period. This stuff is $5 a can and I'd rather waste a can or two of it than cut up the lid on a $70 cooler if I can avoid it.

 

[GrantH]

I'm fairly confused as to what is going on here.

 

[Bobby_M]

The attempt was to make a foam "plug" for the top of the cooler to seal around a corny that is going to stick up through the top. Just get a piece of rigid foam board and cut it to the shape of the cooler. If you want to get fancy, cut a piece of plywood the same size as the original lid and paint it white. Filling the space in with a big mountain of liquid foam just doesn't make sense to me. In regard to the actual question, it shrunk because foam is a structure of air bubbles and since it expanded and set in the sun, it later cooled and the air bubbles contracted.

 

[MMBB]

I'm fairly confused as to what is going on here.

This is what it looks like now.

The attempt was to make a foam "plug" for the top of the cooler to seal around a corny that is going to stick up through the top. Just get a piece of rigid foam board and cut it to the shape of the cooler. If you want to get fancy, cut a piece of plywood the same size as the original lid and paint it white. Filling the space in with a big mountain of liquid foam just doesn't make sense to me. In regard to the actual question, it shrunk because foam is a structure of air bubbles and since it expanded and set in the sun, it later cooled and the air bubbles contracted.

My main reasons for doing it this way as opposed to foam board/pluwood were to avoid having to work with foam sheeting and plywood, cost, and fit. Yeah, it looks like ass but it will insulate better than foam sheeting and, provided it didn't shrink, the seal between the cooler body and keg was very tight. I wouldn't have had to worry about water sloshing out while it is being transported in my car or rolled around.

 

[BBL_Brewer]

Oh, that's what you're trying to do. I thought you were going to mash in it.

 

[rekoob]

how about just filling the gaps now? won't that stuff stick to itself?

 

[nopride]

Maybe try using a piece of plastic egg-crate style panel for lights that can be cut to fit in place. This could provide an internal structure for the foam.

 

[GrantH]

Ah, got ya. Ya I made a dash piece with stuff like that but not great stuff. That stuff...not so great. Find a marine shop in your area and ask for 2 part medium density expansion foam. You pour it in, so you'd have to have at least a foam board (posted board from michaels?) to hold it up but it would be nice and solid (and removable).

 

[MMBB]

how about just filling the gaps now? won't that stuff stick to itself?

I am going to try this tomorrow and let it sit at a consistent temperature overnight. I am going to use the regular expansion stuff and see how that does. I also got another can of the regular expansion great stuff and I am going to try and make an entirely new lid out of that. I'll report back.

If that doesn't work, I may go to a marine store and get the two part foam.

The plastic for an internal structure sounds like a good idea! I may do that when I try the new Great Stuff lid.

 

[GrantH]

I would (personally, had I done this) cut a tight fitting piece of board, tape it off with blue painters tape completely and up/over the coolers edge. Then I would sand it flat however I wanted it and flush with the top of the cooler. Then again, I'm speaking of the two part foam that you can control by pouring it where it needs to go.

edit: I would maybe try filling in the gaps like you said, but you have a LOT of carving ahead of you haha.

 

[MMBB]

edit: I would maybe try filling in the gaps like you said, but you have a LOT of carving ahead of you haha.

Eh, I may just leave it like that. It kinda looks like the head on a beer. I can justify my laziness that way.

 

[starman]

Eh, I may just leave it like that. It kinda looks like the head on a beer. I can justify my laziness that way.

After a bit of UV Great Stuff turns a nasty arse dark brown. You might need to apply sunscreen to your lid when going outdoors.