# Methods Of Insulating A Ss Pot For A Mash Tun



## Dazza_devil (13/10/10)

G'day Brewers,
I'm in the process of researching cost effective ways of insulating methods for my 32 litre SS pot for use as a mashtun. I'm interested in finding some different ideas and perhaps coming up with something new that may work well by upgrading the camping mat solution.
I've done a little research and after purchasing a camping mat found that they can melt if coming into contact with hot wort or a boiling temp pot. Now I'm thinking of ways to avoid this and still use the mat or try a completely different approach.
In another thread Husky came up with an idea of using a few metres of 14w/m heat mat to apply small amounts of heat between the pot and insulation. I also liked his idea of using velcro with the camping mat to fit it snug, easily and securely.
I was thinking one of those emergency thermal blankets may help if incoorporated with the camping mat and then wrapped in a -10 sleeping bag. Perhaps a layer of thick cardboard may help insulate the mat from the pot a little as well.
Any ideas or what works for you? 
I'm also interested in what results peole are getting with varying amounts of headspace in the pot and varying amounts of thermal mass or mash volumes.

Cheers


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## brad05 (13/10/10)

I am also interested in what comes of this thread. I have a s/s keg that I wish to convert to a mash tun. My idea was to make a ply enclosure and use the spray foam stuff from... a certain hardware store to insulate it. I am not sure exactly how I am going to do the lid though.

Hope you get some good ideas. They will help me out as well.

Cheers,
Brad


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## Fourstar (13/10/10)

if i can find a cheap supplier, my plan is to make up a neoprene 'wetsuit' with a zipper for my keggle mashtun. SWMBO sister is app a wizard with the sewing machine so i'll be focusing my efforts her way.

As for the base of the keg, its relatively flat and shallow but will be filled with some sort of filler foam cutout, either syrofoam or something else that can fit snugly with no deadspace. only issue is finding said cheap supplier. at this poiunt all im seeing is rouughly $90 per/m  

this is for standard infusions of course, for anything step mash based, i'll probabaly direct fire it when needed with a relativly thin mash, 3-4:1 ratio.


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## Dazza_devil (13/10/10)

Fourstar said:


> if i can find a cheap supplier, my plan is to make up a neoprene 'wetsuit' with a zipper for my keggle mashtun. SWMBO sister is app a wizard with the sewing machine so i'll be focusing my efforts her way.
> 
> As for the base of the keg, its relatively flat and shallow but will be filled with some sort of filler foam cutout, either syrofoam or something else that can fit snugly with no deadspace. only issue is finding said cheap supplier. at this poiunt all im seeing is rouughly $90 per/m
> 
> this is for standard infusions of course, for anything step mash based, i'll probabaly direct fire it when needed with a relativly thin mash, 3-4:1 ratio.



I was thinking neoprene could be expensive but not that expensive, how much is a full piece diving suit these days?

The real thick rubbery stuff they use for deep winter diving would be the go perhaps with studs or a zip.

Although wetsuits are designed to work when wet, using body heat to warm a layer of water that stays close to the body, so not sure on the effectiveness, maybe no better than a camping mat.


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## Fourstar (13/10/10)

Boagsy said:


> I was thinking neoprene could be expensive but not that expensive, how much is a full piece diving suit these days?
> 
> The real thick rubbery stuff they use for deep winter diving would be the go perhaps with studs or a zip.
> 
> Although wetsuits are designed to work when wet, using body heat to warm a layer of water that stays close to the body, so not sure on the effectiveness, maybe no better than a camping mat.




Have a hunt around for its insulation properties, i think clark rubber website shows it. from waht ive seen, its the perfect prodcut to use, high temperature rated and highly durable.

On a side note, i have two neoprene wine coolers i use for transporting 500ml grolsch bottles to MB meetings. sometimes they sit in the 'wetsuit' for up to 2 hours before they are consumed and are typically below 10 deg still. well worth the investment if you can get it on the cheap. im even tempted to contact ripcurl or a wetsuit manufacturer on the surf coast to see if i can buy some from them/point me to a supplier when im down that way in the summer.


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## Dazza_devil (13/10/10)

Fourstar said:


> Have a hunt around for its insulation properties, i think clark rubber website shows it. from waht ive seen, its the perfect prodcut to use, high temperature rated and highly durable.
> 
> On a side note, i have two neoprene wine coolers i use for transporting 500ml grolsch bottles to MB meetings. sometimes they sit in the 'wetsuit' for up to 2 hours before they are consumed and are typically below 10 deg still. well worth the investment if you can get it on the cheap. im even tempted to contact ripcurl or a wetsuit manufacturer on the surf coast to see if i can buy some from them/point me to a supplier when im down that way in the summer.




Sounds the go then.
You often see old wetsuits in opp shops, maybe a bit of patchwork and you could create something effective and artistic.


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## Fourstar (13/10/10)

Boagsy said:


> Sounds the go then.
> You often see old wetsuits in opp shops, maybe a bit of patchwork and you could create something effective and artistic.




or frankenstein like!


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## Malted (13/10/10)

brad05 said:


> My idea was to make a ply enclosure and use the spray foam stuff from... a certain hardware store to insulate it.



I am not saying don't; just here is some more information for you to consider.
I looked into expanding polyeurothane foam. Good if you're not exposing them to heat, apparently.
Have a read of the back of some of the cans and read their temperature ratings, you may be surprised...

Even fire retardent expanding polyeurothane foam is FLAME retardent not really heat proof. Fire retardent is only good to about 90 degrees celcius.
I am led to believe they can release toxic chemicals when heated.


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## unrealeous (13/10/10)

Clark Rubber store... cheap and cheerful and looks the part. It will handle boiling water.


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## chopdog (13/10/10)

unrealeous said:


> Clark Rubber store... cheap and cheerful and looks the part. It will handle boiling water.
> 
> View attachment 41414




any idea of what the product is called and what did it cost per metre


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## unrealeous (13/10/10)

chopdog said:


> any idea of what the product is called and what did it cost per metre


Its was about 20 bucks a meter - can't recall the name as I just chose it by sight. I went into the store and said I wanted to look at insulation - and they had a whole section of it. So many different types of thickness, grades, some with silver plastic coatings, some without... I'm sure you can find something that will fit the bill.


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## Hatchy (13/10/10)

I went with Mrs Hatchy's yoga mat for my 1st BIAB attempt on Monday & lost 14 degrees in an hour. I really need to find a better solution.


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## brad05 (13/10/10)

chopdog said:


> any idea of what the product is called and what did it cost per metre




and how well it works as an insulator?


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## Fourstar (13/10/10)

chopdog said:


> any idea of what the product is called and what did it cost per metre




Parrot mode: any idea of what the product is called and what did it cost per metre


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## chopdog (13/10/10)

unrealeous said:


> Its was about 20 bucks a meter - can't recall the name as I just chose it by sight. I went into the store and said I wanted to look at insulation - and they had a whole section of it. So many different types of thickness, grades, some with silver plastic coatings, some without... I'm sure you can find something that will fit the bill.




thanks bud :beer:


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## dkaos (13/10/10)

I've seen plenty of people that have insulated their mash tun's with something blue, I think they got it from Clark rubber. Might be an idea to give them a call and see if they have anything that is heat resistant?

Edit:Replied way after I started viewing the thread.


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## dkaos (13/10/10)

Hatchy said:


> I went with Mrs Hatchy's yoga mat for my 1st BIAB attempt on Monday & lost 14 degrees in an hour. I really need to find a better solution.




Hatchy, just use 4 big folded beach towels. That's how I've been insulating up until now and it works a treat! I wrap 1 around it horizontally, then fold one up and drape it, wrap another around, and drape the 4th.

Cheers

Clint


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## unrealeous (13/10/10)

brad05 said:


> and how well it works as an insulator?


Good - but if you don't have an external heat source then you'll probably want to buy thicker stuff and insulate the entire vessel top and bottom. Since I run a HERMS system that provides heat, I haven't bothered to insulate the bottom of the vessel, and just put kettle lid of the top.


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## zebba (13/10/10)

Hatchy said:


> I went with Mrs Hatchy's yoga mat for my 1st BIAB attempt on Monday & lost 14 degrees in an hour. I really need to find a better solution.


Sounds like it would make a better heatsink... Prior to getting an esky I was just wrapping a few towels around my 19l pot. Don't have a lid, so i just put a cake rack over the top and another (folded) towel. Assumming I had the towels around it while it was heating (gotta love electric), I'd only lose 2 or 3 degrees over the hour.

It was certainly not ideal, but definitely better than the yoga mat!!


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## pk.sax (13/10/10)

You might want to look at the location you are brewing in. A draft from a window/door will pretty much do a stellar job o carrying the heat away, as will running exhaust systems. Shut that damn door mate. I lost nothing with just 2 towels and a 19 ltr pot recently so I can tell its not just the insulation, it's WHERE you mash.


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## Lord Raja Goomba I (13/10/10)

a sleeping mat for $5 from Kmart, then the blankets, doonas and towels. I lost a couple more degrees in the last 30 minutes of a 90 minute brew, so I'm going to do this to stabilise temps for the next batch.


Goomba


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## Cannibal Smurf (13/10/10)

Fourstar said:


> if i can find a cheap supplier, my plan is to make up a neoprene 'wetsuit' with a zipper for my keggle mashtun. SWMBO sister is app a wizard with the sewing machine so i'll be focusing my efforts her way.


Glad I'm not the only one who's thought if this 4*. I just emailed the crew at http://www.bluemonkeycreations.com.au/ for some info, will post if/when they reply.

_edit: spulling_


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## Fourstar (13/10/10)

Hatchy said:


> I went with Mrs Hatchy's yoga mat for my 1st BIAB attempt on Monday & lost 14 degrees in an hour. I really need to find a better solution.



the biggest issue with most tuns is deadspace, place a piece of al-foil over the top of the mash and float it.  This works surpisingly well.


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## argon (13/10/10)

I dunno where everyones losing all their heat I tend to lose max 2C over a 60min mash in an uninsulated keggle and I brew outside at night in cold conditions although in QLD so minimum 14C or so most times around 20+. Once Im doughed in I dont open the pot again till mashout last 2 brews I put a bit of foil on top of the grain bed, 1-2C drop max. I reckon if you keep checking for temps youll be losing a fair bit of heat.

Have a search for Browndogs double brewery upgrade hes done a pot in a pot and filled the gap with expanding foam. Its all electric so not suitable for direct firing. But definitely a cool solution for insulating a mash tun.


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## Lord Raja Goomba I (13/10/10)

argon said:


> I dunno where everyones losing all their heat I tend to lose max 2C over a 60min mash in an uninsulated keggle and I brew outside at night in cold conditions although in QLD so minimum 14C or so most times around 20+. Once Im doughed in I dont open the pot again till mashout last 2 brews I put a bit of foil on top of the grain bed, 1-2C drop max. I reckon if you keep checking for temps youll be losing a fair bit of heat.
> 
> Have a search for Browndogs double brewery upgrade hes done a pot in a pot and filled the gap with expanding foam. Its all electric so not suitable for direct firing. But definitely a cool solution for insulating a mash tun.



Slightly OT, but how bizarre is the weather? Middle of October and cool. Plus I couldn't get to work (CBD) monday because the suburbs to my south were flooded (front page of newspaper).

If I get the ingredients, these wet weekends are perfect for brewing though.


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## Hatchy (13/10/10)

Fourstar said:


> the biggest issue with most tuns is deadspace, place a piece of al-foil over the top of the mash and float it.  This works surpisingly well.



I did use alfoil. I reckon my main problems were the deadspace & the fact that I had it sitting on the 3 ring for the hour. Next time I'll use an extra 5-10L of water & wrap something around the bottom. Maybe having it in the sun would be better than under the carport too.


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## levin_ae92 (13/10/10)

I put a sleeping bag over my 60L pot, and I've never lost more than 1deg over the hour mash!


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## Dazza_devil (13/10/10)

I've had a look at the outdoor place and they had three different emergency blankets.
One was heavy duty and an actual bag, looked like it would be really effective but 25 bux. Another was like a big foil sleeping bag and the cheaper 4 dollar job just like a thin foil blanket. The heavy duty one looked a bit stiff and had a layer of something enclosed by the outer foil, might be hard to handle.
I'm tempted to enclose my pot completely in one of the sleeping bag ones and seal it up with the camping mat wrapped around the pot inside and have a sleeping bag as an outer layer. 
My first batch will have a lot of deadspace as well, it's a partial in a 32 litre pot. I'll try the foil over the mash and maybe I should mash with 4 litres/kg for a greater thermal mass but how much is too thin for a partial mash?


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## donburke (13/10/10)

Boagsy said:


> I'm tempted to enclose my pot completely in one of the sleeping bag ones and seal it up with the camping mat wrapped around the pot inside and have a sleeping bag as an outer layer.




do you plan brewing in antarctica ?


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## under (13/10/10)

Until I find something better than what im using, i'll stick with the good old bbq cover. it works a treat, lose about 1 degree over the 90min.


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## IainMcLean (13/10/10)

Guys;

I looked into this a while back. In the brewshed I have a tin of ceramic dust that you add to paint to make it insulating - the same kind of stuff they paint exhausts with. If anyone's interested I can see if I still have the guy's contact details. I haven't used it yet but the guy who sold it to me has used it to insulate gear at wineries with good results....


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## brettprevans (13/10/10)

Ok fellas. Been discussed heaps before. Sleeping bags, camping mats, insulation fromhot water heaters (what I have btw), neoprene (the best and most expensive), car insulation, just about everything from Clarke rubber, expandable foam( I also use that)

Whatever u use it will be ok. 

Also depends on ur climate. If u r in hot climate all the time u don't want neoprene in case u overshoot ur temp, damn hard too cool down. And vice versa.


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## Dazza_devil (13/10/10)

donburke said:


> do you plan brewing in antarctica ?




No, but it does get bloody cold here in the winter.


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## ged (13/10/10)

I also bought some stuff from Clark Rubber. It's silver foil on the outside, black rubber in the middle, and adhesive on the inside. Stuck straight onto the mash tun, haven't lost a single degree in 60 mins. Again, sorry but I don't know the name of it, but it was very easy to find. I found one called "Thermobreak" on the internet, and wanted something like it, and I think this is pretty close.

Ged


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## felten (13/10/10)

What is that stuff they're using at beerbelly for their turnkey brewerys? I remember reading about it a while ago but forgot what it was.


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## Dazza_devil (13/10/10)

felten said:


> What is that stuff they're using at beerbelly for their turnkey brewerys? I remember reading about it a while ago but forgot what it was.




Expensive


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## felten (14/10/10)

word

ps. I use a towel, bubblewrap, then a doona for a long mash. The bubblewrap is the really thick kind with large bubbles.


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## Dazza_devil (14/10/10)

ged said:


> I also bought some stuff from Clark Rubber. It's silver foil on the outside, black rubber in the middle, and adhesive on the inside. Stuck straight onto the mash tun, haven't lost a single degree in 60 mins. Again, sorry but I don't know the name of it, but it was very easy to find. I found one called "Thermobreak" on the internet, and wanted something like it, and I think this is pretty close.
> 
> Ged



Ged, how big is your pot and what volumes do you mash?
I was interested in how the camping mat solution can be modified, since I already have one. We don't have a Clark Rubber here but this gives me an idea.
Perhaps if I glue the heavy duty emergency blanket material to the outside of the camping mat, giving it a dual layer. Maybe there is another substance I could glue to the inside to improve it further.

People that use the camping mat, do you cut it to fit under the pot lip and from the top of the base where the side of the pot is vertical, cutting slits for the handles? How do you attach it and are there other solutions for the bottom and top of the pot other than the towels, blankets, etc.?


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## goldstar (14/10/10)

I believe the insulation used by Beerbelly is called Aeroflex. I think there are a few guys on the forum that have also used it. Check out www.aeroflexinsulation.com Would be great if more information on its use / where to buy etc could be posted.


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## Supra-Jim (14/10/10)

I spoke to Beer Belly recently, inquiring about aeroflex and they quoted about $55 per linear metre, the roll is approx 1.3m wide. From quick calcs, this vwould be enough to cover a 50 ltr keg shaped tun.

Cheers SJ


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## Supra-Jim (14/10/10)

I spoke to Beer Belly recently, inquiring about aeroflex and they quoted about $55 per linear metre, the roll is approx 1.3m wide. From quick calcs, this would be enough to cover a 50 ltr keg shaped tun.

Cheers SJ


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## MarkBastard (14/10/10)

I currently have a 40L urn and I have attached a $5 blue camping mat to the outside, held in place with some old belts.

I put the lid on the urn (not insulated) then cover the lid in a towel, then cover the whole thing in a big blanket.

It works well (about 1.5 degrees lost over the hour) but it's annoying using the big blanket. I'd much rather be able to do one of the following.

1 - Insulate the urn with better passive lagging and also insulate the lid of the urn so that I only need put the lid on and walk away.
2 - Make an insulated cover for the whole urn that's exactly the right shape. Like a big upside down stubbie cooler, perhaps even with some straps at the bottom to tighten it so it hugs the urn at the bottom.

I don't know if option 1 would ever give the right performance because the heat would likely find a way out, but number 2 I reckon would give better performance than my current method if done right, and it could be used as an urn cover when the urn isn't in use as well.


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## Doogiechap (14/10/10)

Browndog's guide is pretty impressive with his expanding foam sandwiched between two stainless pots.


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## Dazza_devil (14/10/10)

Supra-Jim said:


> I spoke to Beer Belly recently, inquiring about aeroflex and they quoted about $55 per linear metre, the roll is approx 1.3m wide. From quick calcs, this would be enough to cover a 50 ltr keg shaped tun.
> 
> Cheers SJ




That sounds pretty good. By the time you stuff around trying to find cheaper ways of doing the job it's probably gonna cost more and be inferior. Depends what you are gonna be up for by the time the stuff is installed on your pot, interesting to find out.


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## Simon66 (15/10/10)

levin_ae92 said:


> I put a sleeping bag over my 60L pot, and I've never lost more than 1deg over the hour mash!



Use the same works really well, and I still use the sleeping bag for my many camping trips.

Also I have the basic three ring burner with bricks as the stand. The bricks are a heat bank. Heat the strike water in my 40 litre aluminium mash vessel and the bricks heat up significantly. I have actually gained a little increase in temperature over an hour from the hot bricks and sleeping bag insulation.

I also like the idea of removable insulation as it allows me to do step mashing. Depending on the the insulation you use, you may not be able to add a flame to the mash tun to do step mashing or even raising the mash temperature for mash out

Simon


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