Filling Cooler Walls with Spray Foam

Joronimo

New member
I have heard of a few people trying this second hand but haven't actually talked to the person who did it. Anyone on here ever try this? I would like a Yeti cooler but won't spend $350 on a cooler. I know they work well but I'm sure I'll break it or it will get stolen before it pays for itself.

I have a cheap cooler from Walmart that works OK for short trips but when we go on longer trips (2 days +) I need to refill it with ice. Granted this is usually a drinks cooler so its opened and refilled with warm drinks a lot.

cooler.jpg

I want to drill holes in the bottom and maybe sides to fill it with Great Stuff Window and Door spray foam. The window and door foam is supposed to put less pressure on the structure so I'm hoping that means it won't deform the cooler too bad.

Great Stuff.jpg

Any way, for $12 in foam and risking a $20 cooler it might be worth it. Worst case, I'll have a reason to buy a better cooler if its destroyed.

If anyone has tried it, let me know if you have tips or tricks. I'm going to try it this weekend and see what happens.
 

thethePete

Explorer
I've been considering doing this very thing to an old, but really neat cooler I have that doesn't cool so well anymore.

I plan to fill my cooler with water in an effort to keep the foam from displacing the inner walls or swelling them.
I plan to do the lid as well, and with it, I plan to put a board with some weight on it for the same reason. When I finish with foaming the body of it, provided I didn't wreck it in the process, I plan to apply a liberal bead of silicone around the lid to help seal it better. I'm thinking I might take this project on this weekend, since I don't think I'll be making it out camping. I'll do a little write-up/thread about it when I do.
 

loudboy

Observer
When building my motorcycle, I tried making molds for body parts out of spray foam by filling a 5-gallon bucket with the stuff.

The top couple inches dried, but the bottom stayed a soupy mess. Without being able to off-gas, it doesn't cure. I doubt it would ever cure in the enclosed space of the cooler walls.
 

conifers4

Suburban nomad
When building my motorcycle, I tried making molds for body parts out of spray foam by filling a 5-gallon bucket with the stuff.

The top couple inches dried, but the bottom stayed a soupy mess. Without being able to off-gas, it doesn't cure. I doubt it would ever cure in the enclosed space of the cooler walls.
Interesting
 

Joronimo

New member
When building my motorcycle, I tried making molds for body parts out of spray foam by filling a 5-gallon bucket with the stuff.

The top couple inches dried, but the bottom stayed a soupy mess. Without being able to off-gas, it doesn't cure. I doubt it would ever cure in the enclosed space of the cooler walls.
Good info. I'll drill some vent holes and see if it cures better with that. Any idea if the stuff heats up as it cures?
 

njtacoma

Explorer
I did a google search on this 6 months ago, and there were numerous posts on different websites that ran into the same off gassing problem. Also something about a reaction between the plastic and the foam that didn't allow it to cure.

i'm curious of your results.
 

chet6.7

Explorer
My experience with using the foam on a cooler is limited,I did it once.I may have used a foam that expanded more than another,I just grabbed a can off the self not knowing the difference.The stuff did deform the cooler a bit,I am not sure I got a good flow into the cooler,I would drill more holes if I did it again.
I think having more holes would allow better flow,more coverage and allow better out-gassing.
I put reflectix on the outside and the inside it did seem to help with the insulation,but I was building a box for an outside cat.The box was warmer,had a heating pad as well,than it was before the mods.
 

IdaSHO

IDACAMPER
When building my motorcycle, I tried making molds for body parts out of spray foam by filling a 5-gallon bucket with the stuff.

The top couple inches dried, but the bottom stayed a soupy mess. Without being able to off-gas, it doesn't cure. I doubt it would ever cure in the enclosed space of the cooler walls.
That's because you used the wrong foam.


Nothing out of a can will cure more than a couple of inches from the surface.

You need a true two-part (chemical cure) foam to do that.

Google FROTH-PACK for an example of the correct foam to use.
 

borison

Adventurer
I tried that spray foam in a mug with dead space between the liner and outer shell. Bad bad bad. Did not expand into all the space, blew out the access hole and sprayed foam 5' in all directions.
 

TwinStick

Explorer
I have done this. I used the regular yellow foam. I drilled multiple holes, actually a lot of them. More than 10 on each side I think. Same with the lid. Yes, it did come out the other holes. I think I only used about 4 holes with the nozzle, on each side, the rest were to keep it from deforming. Did it cover 100% of the inside---IHNI. It seemed to as it held ice for another day or 2. I let it dry all day & all night, about 24 hours, on a warm summer day. I cut off the excess with a knife. It did make a mess of the outside of the cooler, but once it dried, no more worries. Just cut off what you can. I have since gotten rid of that cooler at a garage sale. We have 2 ARB fridge/freezers now & 2 Coleman extreme coolers that we use for drinks. We can refreeze the ice jugs overnight in the ARB, & rotate them.
 

Joronimo

New member
I finally got around to trying this out. It has been raining a lot which kept me form working on it.

I drilled 6 holes in the bottom and found that the bottom and sides are already filled with foam. I didn't expect that from a cheap cooler so I'm guessing my gains will be minimal.

IMG_1392.jpg

I ran a wire coat hanger all the way through these holes to verify it was completely filled.

Next i drilled f holes in the lid and started filling.

IMG_1394.jpg

I put a little water in each hole and began filling. I worked my way around putting the straw in as far as possible to get the foam in deep before it expanded. I believe i got it filled pretty well as the lid seems much more solid and foam kept coming out of the hole on the top right for about 20 minutes after. Ill try to get a "test" this weekend. Before i got an 8 pound bag of ice and I would estimate it melted half way (4 pounds left) from 5pm to noon the next day. Ill try this again, not scientific but maybe a good reference.

All I need to do now is fill the holes with some epoxy or something. I thinking like JB Weld or something similar.
 

bwestfla

New member
I don't think you will see much change. The foam the yeti uses is a polyurethane foam blown with 245fa which gives it a much higher r-value. Froth packs will have about the same r-value as air which is what you have now. The difference is about double. 3.5 vs. 6.5.

Cool experiment though.
 
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