mash tun insulation

[soneil8]

Hi All,

Looking for a bit of advice on insulating my mash tun. What is the best stuff to use?

I have used Armaflex before http://www.amazon.co.uk/Armacell-Armafl ... B00BJL7BL0 but as you can see, it's expensive!

cheers guys!

[lord groan]

There are so many different possibilities!
Camping mats for sleeping on are about 90cm wide and 1.90m long and much the same thickness as that armaflex, but only cost about£4-5 new or I've used ones from a car boot sale that cost 50p each. Not quite as thermally efficient but you could just use more layers.
My first MT used a big polystyrene box with gaps filled with builders foam to sit in, that worked well but I still got a drop of 2-3degrees
My 2nd is an old insulated steel boxed Coleman coolbox, because it is rectangular I have built a box from 25mm thick kingspan insulating sheet to totally enclose it. That gives fantastic results, no more than 1degree drop over 90 mins.
I know some people use aluminium foil covered bubble wrap, some use duvets or blankets, and some talented souls build beautiful wooden enclosures.
So there are lots of different possibilities, just go with whatever suits you best!

[soneil8]

I have the foil bubble wrap just now (its a new kit I bought recently). but my last experiment showed a drop of over 1 degree in 90minutes.
With the armaflex, I lost 0.3 degrees over 90minutes!!!!!

Thanks for the good ideas there Lord, I'll mull over the different possibilities!

[JamesF]

Looking at some numbers I'd estimate that the Armaflex linked above is about twice as good an insulator as foil-backed bubble-wrap, so more than one layer of the bubble wrap might well do the same job for a lot less money.

Unsurprisingly perhaps, I can't find any useful insulation data for cheap camping mats, but I suspect that a couple of layers of camping mat will do just as good a job. For those who like shiny stuff, I see you can even get foil-backed camping mats these days. I don't know if the foil will help at all. I guess it is intended to act as a radiant barrier, but if it's really effective on the other side of the foam is anyone's guess.

James

[BenB]

I went for the foil backed foam mat. Seems to work well. Totally unscientific but when the boil is on full I cannot feel any heat when i grasp the boiler. .. so clearly it's doing something! !

[UpTheToon]

I have the foil bubble wrap just now (its a new kit I bought recently). but my last experiment showed a drop of over 1 degree in 90minutes.
With the armaflex, I lost 0.3 degrees over 90minutes!!!!!

Thanks for the good ideas there Lord, I'll mull over the different possibilities!

Just looking at Armaflex now for my BIAB pot. What thickness did you get? Did you get the self adhesive stuff? Not sure if that's the best idea for mine as its also my kettle...

[BlackRocksBrewery]

I built an insulated jacket for a friend who wanted to convert his 30litre stainless steel conical bottom container into a mash tun. Without any calculations we decided to build a plywood frame and fill it with polyurethane foam. The minimum gap between the cylinder and the plywood is about 35mm and the plywood is around 20mm. This is not a delicate item but it holds temperature better than my attractive and perfectly adequate mash tun from Mr Lard at the Home Brew Builder.

In the past I have used insulated food containers and containers wrapped in high density camping bed foam. Prior to my current mash tun I was using an Igloo water cooler. This was really good but it did lose more than 1deg C per hour. I was planning to put further insulation in the hollow lid but I bought the double skin stainless steel one instead.

[Fil]

i did a bit of homework on the subject, composite layer insulation is the best, and the £shop sells cheapo foam groundmats, bubblewrap, and mylar sheet (space blankets) for the outside layer spend a little more on a quality wipe down or washable surface..

there is an interesting study on the web regarding a steam balloon and the various balloon fabric/composite skins that proved effective, and a bubblewrapp/mylar composite proved the most effective insulator.



my conical is insulated with cheap £shop groundmat bubble wrap and mylar, with an outer wrap made from a quality (wipe down and tear resistant exrercise mat.



when trying to insulate my keg store, i had 1cm stand off battons so fitted 2 x mylar and 2 x bubble wrap sheets in the gap.. width space was a premium i needed to accommodate a washing machine And kegs side by side..

[UpTheToon]

Lots of inventive people on here!

I've used 19mm armaflex and aluminium tape to do the walls of my pot. Have enough left to cover the lid too.

Aluminium tape is a bit of a pain to work with and I noticed it pulls away some of the insulation if you try and remove it. I've taped the seams so hoping I can stop any liquid getting down the sides and keep it clean.