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.
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.