Filling mash tun lid with insulation

The other day I decided to fill my hollow mash tun lid with expanding foam insulation (That Great Stuff stuff). Thought I'd pass on some tips:

1) Wear gloves and put plastic on your workbench
2) Drill at least two holes so the trapped air can get out
3) The can has a little little plastic tube/applicator thing. When you put that into the hole you drilled, don't move it from side to side - it'll break off (as I learned the hard way)
4) After the lid was filled, I balanced the lid across the top of a garbage can. That way, as the foam expanded and leaked out the holes, it just fell into the garbage.
5) If you drip some on your workbench/floor, leave it. After it cures, you can just pop it off the workbench/floor in one piece. Trying to wipe up uncured foam is a PITA and it makes a bigger mess.

I have had this exact thought many many times......now i just need to do it.

JonM said:

The other day I decided to fill my hollow mash tun lid with expanding foam insulation (That Great Stuff stuff). Thought I'd pass on some tips:

Click to expand...

What type of cooler was it?

I would suggest drilling at least four holes in the lid; one on each side as vents to allow the foam to displace the trapped air. Shoot the foam into each hole sequentially for best results. Don't over do it with the foam or it can bulge the lid. You can press down on the lid to purge excess foam which will help minimize the bulging. Keep an eye on it for the first few hours and squash it some if necessary. It is difficult to judge how much foam to use and it will vary from lid design to lid design. Insulating the lid makes a huge difference in the rate of heat loss. It's not an issue when used as a cooler, but it is a major one when trying to keep something hot.

Coleman Xtreme. Is the lid already insulated? I didn't lose any heat during my first mash, although I had it wrapped in a sleeping bag due to it being 34F outside.

Just wondering if I should go ahead and insulate the lid or if it is already insulated...

Ace_Club said:

Coleman Xtreme. Is the lid already insulated? I didn't lose any heat during my first mash, although I had it wrapped in a sleeping bag due to it being 34F outside.

Just wondering if I should go ahead and insulate the lid or if it is already insulated...

Click to expand...

Take a close look at the lid. Press down on the top and you can probably judge by the deflection if it is insulated or not. Most ice chests do not have an insulated lid, but it they will usually be hollow which offers some degree of insulation. Cool air will tend to pool to the bottom of the ice chest, so not much is lost through the top when used as an ice chest. It's the opposite when trying to keep something warm as the heat will rise to the top and most of the heat will exit through the lid. The sleeping bag added a huge amount of insulation and protected the cooler from air currents. We would all be using sleeping bags if it wasn't such a hillbilly approach. It's very effective.

Catt22 said:

We would all be using sleeping bags if it wasn't such a hillbilly approach.

Click to expand...

Considering my AG stand is a basketball post, hillbilly fits right in.

Nevermind, I found my answer on amazon:

The large icy blue cooler and white lid are lined with a full two full inches of insulation

Will filling the lid on a round 10 gallon Rubbermaid cooler really help all that much? Is it worth it filling with insulation or will a heavy blanket do the same?

The rubbermaid coolers probably benefit the most.
the insulation will do a better job of filling the void inside the cooler, which slows the loss of heat more than a blanket.

but it could be a negligible difference with the volumes we are dealing with.

ultravista said:

Will filling the lid on a round 10 gallon Rubbermaid cooler really help all that much? Is it worth it filling with insulation or will a heavy blanket do the same?

Click to expand...

I have never bothered insulating a cooler lid and have never seen the need to. I do brew indoors though. Last batch w/ an igloo 48 cube I had almost no difference in temp at the end of the mash??

Insulate the lid if you wish, but try the tun first and see if you have a problem would be my advice...oh and preheat the tun well by overheating sparrge, water works for me.

With my 48qt coleman, I would lose 4-5° over a one hour mash. I recently insulated the lid, and on a 90 min mash last weekend, I only lost 1°. I mash in my garage, or basement, depending on outdoor temps. I also preheat the tun.

Sent from my DROIDX using Home Brew Talk

wilserbrewer said:

I have never bothered insulating a cooler lid and have never seen the need to. I do brew indoors though.

Click to expand...

I can see where brewing indoors at 68° might be different than outdoors when it is 10°. I use an electric blanket on the top of my Igloo cooler. I've brewed enough batches that I don't have to open the lid too often and I can hold temperature.