This is how i reduced my headspace in my masttun

[weirdboy]

I originally was gonna use this http://m.lowes.com/mt/www.lowes.com...etInfo=&un_jtt_v_tabs=description#description

But I had the styrofoam so I went with the free route. That stuff is only $3 though. Seems like it would work perfectly

That link does not work. What is the name of the product?

 

[Kmcogar]

Insulfoam at lowes

 

[tre9er]

I tried the spray foam insulation on my lid and it didn't expand - actually, it appeared to expand, then later collapse. I have since heard that it needs moisture to work properly, so maybe that is why it sometimes doesn't work when you spray it into small holes in the lid. Anyone tried spritzing a small amount of water in before the foam?

I used the low expansion "Great Stuff" for "Windows and Doors"

I was planning on making a few holes, larger than they "need to be" and spraying it in from a few angles. I can silicone the holes back up later once the stuff expands. Even if it doesn't fully expand I guess it's more insulation than just plain plastic.

 

[ekjohns]

I have tried adding only a little, adding a lot, with moisture, without moisture and nothing works. I always notice that the holes look like the foam expanded and hardened but if you drill another hole 1" away there is no foam. This is why I think people say the have done it "successfully" when they really didn't. I have thought about cutting a 1" hole and just manually pack the lid with ground up packing peanuts.

 

[ekjohns]

I was planning on making a few holes, larger than they "need to be" and spraying it in from a few angles. I can silicone the holes back up later once the stuff expands. Even if it doesn't fully expand I guess it's more insulation than just plain plastic.

Tried it and it didn't really work for me with 1/2" holes

 

[tre9er]

Tried it and it didn't really work for me with 1/2" holes

Last option is cut the top of the lid off and spray the foam directly onto the inner chamber, let expand some, masking tape lid on, later silicone around seam.

Otherwise is there something more liquid-y that could be poured into the lid until full then allowed to cure?

 

[wilserbrewer]

Spray foam can be messy and a huge pain in the ass if it doesn't set up, therefore, I have always chosen to preheat the cooler thoroughly and either anticipate, or live with 1-2 degrees loss over an hour. If you really obsess, toss a blanket over the cooler during the mash.

 

[tre9er]

If you really obsess, toss a blanket over the cooler during the mash.

Which is what I've always done. Usually don't lose more than a degree.

 

[HangLoose]

If you thought that I was suggesting that insulation is unnecessary you misread me. I was simply saying that GIVEN a level of insulation in the lid, the marginal effect of the headspace on heat loss would be negligible. I still think so. Anyone who thinks not can do what he likes to address it. I won't. That's all.

I agree its marginal. I thought that's what we were discussing. Saving a degree or two an hour sounds marginal to me. I don't bother to insulate my head space just for this reason (plus I have a RIMS).

I disagree with your attic analogy BTW, I mean it seems to me insulating your roof would really help keep heat out (like on a hot day). Try this: crawl under a blanket on a cold night, then lift the blanket up off of you by a foot or two (keeping it sealed on all sides) will you be:
a) a little warmer
b) the same
c) a little cooler
You say warmer, I say cooler. The difference would be small but it would exist.

 

[ekjohns]

I use a 10 gal igloo preheat for 20 min the add grain and a 2" styrofoam lid the the cooler lid and still lose 3-4 degrees. I also add the grain 2 degrees hotter and stir the piss out of it till my arm is dead and usually close it up 1 degree hotter than the target. What am I doing wrong. My grain to water ratio is 1.30

 

[wilserbrewer]

I use a 10 gal igloo preheat for 20 min the add grain and a 2" styrofoam lid the the cooler lid and still lose 3-4 degrees. I also add the grain 2 degrees hotter and stir the piss out of it till my arm is dead and usually close it up 1 degree hotter than the target. What am I doing wrong. My grain to water ratio is 1.30

my guess would be that you are not preheating adequately, or you are not wating long enough for the grain water temp to stabilize...the mash temp will drop for about 5 minutes till it becomes constant...checking it too soon will indicate false highs IMO.

 

[HangLoose]

I use a 10 gal igloo preheat for 20 min the add grain and a 2" styrofoam lid the the cooler lid and still lose 3-4 degrees. I also add the grain 2 degrees hotter and stir the piss out of it till my arm is dead and usually close it up 1 degree hotter than the target. What am I doing wrong. My grain to water ratio is 1.30

Are you taking the starting temperature of your grain into account?

 

[tre9er]

This is why I heat strike to 180 and pre-heat my tun with it. I leave it in there for a good 10 minutes then stir down to just ABOVE prescribed strike temp from software and dough-in a little high. I stir like crazy and then once I'm in the upper range of my mash temp, cover it up and throw a blanket on it.

 

[ekjohns]

This is why I heat strike to 180 and pre-heat my tun with it. I leave it in there for a good 10 minutes then stir down to just ABOVE prescribed strike temp from software and dough-in a little high. I stir like crazy and then once I'm in the upper range of my mash temp, cover it up and throw a blanket on it.

this is exactly what I do, only I preheat for 20 min and still loose 4 degrees over 1 hr. usually with about 11 lbs of grain

 

[tre9er]

this is exactly what I do, only I preheat for 20 min and still loose 4 degrees over 1 hr. usually with about 11 lbs of grain

Weird. I lose about a degree, if that. I've always liked the way this cooler held temps even though it's not fancy or expensive. It's a rectangular 7g. cooler, maybe an igloo or coleman...not sure.

 

[Rundownhouse]

I've tried a couple 5gal/~12lb grain batches in my 25g mash tun and it loses heat at a crazy pace compared to when I've got a 10gal/~25lb grain batch in there.