New Insulated Keggle Mashtun

Well after much laziness and determination I finally created a BobbyM style keggle mashtun for my direct fire mashtun. Props go to him, as I took his design to a tee.

Here's the keggle wrapped with holes drilled for the thermos and spigots. I had to re-drill them a bit as the original placement was less than perfect.







Here's the finished product. I added some square pieces of aluminum over the holes and riveted them in place and added caulking to make sure no wort ever gets into the wool through the holes.





Then I caulked the hell out of the inner rim of the keggle. Covered the handles too for watertight fit. Lastly I caulked the top of the wool so nothing wet gets in there.







Then I added some reflectix wrap to make the top as insulated as possible. Added 3 layers to slip over the lid and then 3 more on top of the whole thing to fit snug. I have not done heat tests yet. But I am confident to have only a couple degree loss over an hour.







Here's a pic of the back. I opted for a permanent solution instead of the hinges as I felt the hinges were too weak to hold the aluminum sheet together. I had to cinch it down very tight with the racketing straps to get the wool to form fit around the keggle. I thought the rivets would hold better.



Here's a shot from underneath to show the thickness of the wool.



Lastly, is Jaybird false bottom.

Geez - where's the love.

So I finally test the insulating capabilities of this thing. Brought 6.5 gallons up to 154F.

After 60 minutes temps were at 153.5.

After 120 minutes temps were at 150.

After 150 minutes, temps were still at 150.

I am psyched over this.... Won't need to fire up the kettle to increase temps at all, unless I am step mashing.


temps

Looks awesome. I assume there is no worry about the open flame and the insulation?

None. This stuff is fireproof. However the outer shield sure gets hot.

How much did it all cost? I do BIAB in a Keggle on a Top Tier burner... and during the winter months with the cold air blowing around I loose a lot of heat.... also you don't happen to have his original thread handy do you?

Wow that's awesome!!!

Total costs was about $75 which was mostly shipping costs for the sheeting and insulation.

Here's the original thread from BobbyM

https://www.homebrewtalk.com/f51/direct-fire-mlt-insulation-project-154652/

ghart999 said:

Total costs was about $75 which was mostly shipping costs for the sheeting and insulation.

Here's the original thread from BobbyM

https://www.homebrewtalk.com/f51/direct-fire-mlt-insulation-project-154652/

Click to expand...

Nice job. Thanks for the info.

please note, most if not all wool insulation is merely Fire resistant, not fire proof.

CCBrewer said:

please note, most if not all wool insulation is merely Fire resistant, not fire proof.

Click to expand...

Well maybe I correct myself here. I imagine a direct flame for extended period of time would cause a problem. But then again this is used for a mashtun, not a boil kettle. As such there is no reason on earth you would be blasting a burner at this which such voracity that flames are licking up the sides.

The stuff is rated to 1200F. I will say that I had my burner (BG-12) on full throttle getting my water to 154F. There were no flames going up the sides and certainly no issue with burning or even a scent or weird smell.

ghart999 said:

Well maybe I correct myself here. I imagine a direct flame for extended period of time would cause a problem. But then again this is used for a mashtun, not a boil kettle. As such there is no reason on earth you would be blasting a burner at this which such voracity that flames are licking up the sides.

The stuff is rated to 1200F. I will say that I had my burner (BG-12) on full throttle getting my water to 154F. There were no flames going up the sides and certainly no issue with burning or even a scent or weird smell.

Click to expand...

I'm bumping this for future reference.

Maybe I can clarify this somewhat. I've worked professionally with refractories and insulation for 15 years. Humble as I am, I would describe my knowledge of this as " highly adequately". Please also note that I'm European so i work with deg. C. But I will try to use F.

The only problem I see with using mineral wool for this application,is not the material itself. The material will withstand the temperatures. On the other hand the material contains a binder that will evaporate at 390F-490F. The vapors are hazardous and you don't want to breathe in these vapors.

I've never used a burner (I'm electric), so i have no experience in the flame heat focus, but I would be somewhat hesitant to take this path without doing some testing.

One alternative would be if you could find some ceramic vermiculite (The lightweight stuff that you line your fireplace with, not the heavier chamotte bricks found in "open" fireplaces). These can be poured in a mold, like you steel sheet (but this would probably require some kind of controlled dry out to get rid of the water).

Still, nice work! And believe your'e fine.