my spray foam insulation wont expand?

[ekjohns]

Okay so I got the old yellow igloo 10 gal cooler with the red hollow lid for a mash tun to batch sparge in. After a 1 hr mash I loose about 6 F even after i preheat for 20 min with a blanket on the top. When im done mashing everything is cool to the touch except for the lid which is very warm so I am assuming thats is where i am losing all my temperature.

Easiest fix Spray foam insulation in the lid... or so i thought. I bought 1 can of general "Great Stuff" and sparyed it through 4 holes drilled in the top but never got any expansion. I didnt shake it very well so I assumed that it didnt expand cause of this. So I went and got another can of great stuff and shook the hell out of it and sparyed it in 6 new holes and BAM! filled the lid nicely and had thick foam shooting out of all the holes. I let it sit over night to harden and figured i would cut away the foam that oozed out the next day. To my surprise i broke away the excess foam to find the foam in the lid is gone! I stuck a screw driver in the lid and there is no more foam just a very thin layer of slime on the bottom. What am I doing wrong? I'm stumped, Im about to cut a 2"X2" square and just pack it with something.

 

[Smashing]

Can't help you with the foam BUT what I did was a little different. I bought a sheet of pink styrofoam, cut out a circle so it would fit in the cooler, wrapped it in foil, poked 3 holes in it, used 2 hole to thread a zip - tie through, loop the zip-tie to make a little pull tab and used the 3rd hole for my long stem thermometer. Now you have a height adjustable mash tun. You'll be able to push the foam right down to the top of the mash and eliminate any headroom issues. I loose zero degrees over the course of an hour with mine.

 

[JTGraese]

Man, Thats a great Idea. I think I am going to have to try that out on my Rubbermaid 10 gallon. Thanks!

 

[kegtoe]

Okay so I got the old yellow igloo 10 gal cooler with the red hollow lid for a mash tun to batch sparge in. After a 1 hr mash I loose about 6 F even after i preheat for 20 min with a blanket on the top. When im done mashing everything is cool to the touch except for the lid which is very warm so I am assuming thats is where i am losing all my temperature.

Easiest fix Spray foam insulation in the lid... or so i thought. I bought 1 can of general "Great Stuff" and sparyed it through 4 holes drilled in the top but never got any expansion. I didnt shake it very well so I assumed that it didnt expand cause of this. So I went and got another can of great stuff and shook the hell out of it and sparyed it in 6 new holes and BAM! filled the lid nicely and had thick foam shooting out of all the holes. I let it sit over night to harden and figured i would cut away the foam that oozed out the next day. To my surprise i broke away the excess foam to find the foam in the lid is gone! I stuck a screw driver in the lid and there is no more foam just a very thin layer of slime on the bottom. What am I doing wrong? I'm stumped, Im about to cut a 2"X2" square and just pack it with something.

if there was foam originally in the lid the great stuff may have reacted with it, and degraded it, especialy if your original can didnt expand. also there is a low/no expanding spray foam too so you have to be careful what your buying. If there was moisture in the lid, that might have been an issue to. a lot of foam products dont stand up well to water. if there was moisture in the lid it may have prevented curing. I like the 2nd poster's idea of styrofaom wrapped in reflectix. Make sure you use the water resistant foam in that application though.

 

[ekjohns]

I might try that as well since I do 5 gal batches in a 10 gal cooler it should help.

Smashing how tight does your circle fit. I assume its good enough to hold its position but not too tight to break the foam. Also do still put the cooler lid on after the foam?

 

[ekjohns]

kegtoe - the foam i used both times was the original high expanding foam. The only thing I can think is i added almost the whole can each time and that may be so much foam in such a little space that it cant get a good mix with the air and colapses under its own weight/pressure. The moisture should actually help since it says on the can to spray it with water to help harden it. Ill give it one more go with my last can (donated by a friend) and spray much less to see if i can get a good expansion that will hold. In the mean time im also gonna try and macromade myself an adjustable lid.

 

[justtaint]

Something is causing your foam to collapse (oil?). Clean out the inside of the lid as best as you can, let it dry (get all the moisture out, as water acts as a blowing agent and will throw off the density). Don't waste your last can until the inside is clean.

 

[ekjohns]

ill try and clean it but its going to be tough through those small holes and that colapsed foam is like super thick honey and water insoluable. Im afraid of putting in organic solvents with the risk of melting the plastic

 

[justtaint]

Acetone will melt the plastic. Isopropyl Alcohol should be safe. Swish it around in there for a few minutes, drain, and do it again. If the second wash comes out clean just let it dry, otherwise wash, rinse, repeat until the IPA comes out clear.

 

[Brewfat]

Can't help you with the foam BUT what I did was a little different. I bought a sheet of pink styrofoam, cut out a circle so it would fit in the cooler, wrapped it in foil, poked 3 holes in it, used 2 hole to thread a zip - tie through, loop the zip-tie to make a little pull tab and used the 3rd hole for my long stem thermometer. Now you have a height adjustable mash tun. You'll be able to push the foam right down to the top of the mash and eliminate any headroom issues. I loose zero degrees over the course of an hour with mine.

This is exactly what I do, works great. I have no heat loss over an hour.

All I do to preheat is add a gallon or so of hot water from tap while the strike water heats.

 

[ekjohns]

okay so I tried some IPA swished it around, let it sit and drained it and...nothing. The alcohol came out crystal clear and removed absoultly nothing. Would cutting a small square out and cramming a bunch of fiberglass insulation in then sealing it back up with the square i cut out with epoxy work?

 

[Hang Glider]

probably not.

I really think that it is the plastic at fault. Almost no glue will stick to 'cooler' plastic, including epoxy.

I think the plastic is at fault with the Great stuff foam as well. Coolers are made of Low Surface Energy plastic (google this). Higher surface energy promotes bonding,
Low surface energy products are easy to clean, hard to bond.

special glues are required, like this

 

[ThePearsonFam]

Have you tried spraying just a little bit into one hole and letting it sit? Perhaps the expanding foam just needs someplace to fully expand into before setting up? Maybe drill one hole right on the outer edge and spray just a little bit into just that one hole. Let it sit and see what happens. You can continue to work across the lid if that works, or just get it the best you can and accept that anything is better than nothing.

 

[camus]

Are you shaking the can? Is it freezing cold, the can or where you are spraying and letting it cure?

You should be able to spray that stuff in a plastic gas can half filled with gas and see it expand.

 

[ekjohns]

Everything was at room temp. I think i was sparying to much which isnt giving it a good area to expand as ThePearsonFam mentioned. This weekend im gonna try my last can with spraying alot less and see if that help. I was thinking this since the foam that was shooting out of the holes set very nice since it was unconstricted but the stuff that had minimal area to expand colapsed. The only thing that worries me right now is that it will have problems expanding since there is a bottom layer of colapsed foam already. If that doesnt work Ill just make an adjustable lid out of styrofoam.

 

[Smashing]

I might try that as well since I do 5 gal batches in a 10 gal cooler it should help.

Smashing how tight does your circle fit. I assume its good enough to hold its position but not too tight to break the foam. Also do still put the cooler lid on after the foam?

I make it nice and snug so it takes a little force to slide down. I traced the inside of the lid and used a drywall saw to cut it out. I've been putting the lid on only cause there is still room to do so. Every little bit helps. The foil helps in cleanliness and to help keep foam out of the mash. Do it and you will never look back. I'm even going to do a rectangle one when I change coolers for when I start 10gal batches.

Man, Thats a great Idea. I think I am going to have to try that out on my Rubbermaid 10 gallon. Thanks!

Do it!

 

[Smashing]

One thing I just learned. Spray foam is only good for 1year after packaging. Check the bottom of your can.