Minnie Mouse Fitted with a Cob Hat

That's a great and simple solution. Does that rocket mass heater get cleaned out yearly? If so,  can the cob hat be lifted off with the top of the barrel or would the cob hat have to be rebuilt yearly after the barrel is cleaned?

Rex Holliday wrote:That's a great and simple solution. Does that rocket mass heater get cleaned out yearly? If so,  can the cob hat be lifted off with the top of the barrel or would the cob hat have to be rebuilt yearly after the barrel is cleaned?

I would imagine it would have to be rebuilt, or at least shored up, if it's moved. In my experience, cob and mud will crack and crumble when jostled.

The top half at least of the cob hat is apparently not going to get so hot as to char any straw in the cob, so I would suggest that when a replacement is made enough straw is included to make it strong enough to pick up. Also, forming a couple of holes in the cob in such a way that sticks or hooks could be inserted to lift the hat securely would contribute to its longevity.

What do you estimate the weight to be, Stephen? I'm thinking of a small hoist to do the lifting....

I've got a 4" J-tube in my greenhouse that would benefit from this treatment. The barrel is a 100-litre grease drum and it sits on a round channel formed in cob with a fire rope gasket, so it's easy to lift for inspection and cleanout. I also cut out the top of the barrel when it collapsed from spalling and there's now a piece of 6mm steel plate that sits on the rim, again with a fire rope gasket, for a vastly improved cooking experience.

What I've been doing is putting three big rocks on the plate to act as thermal mass. What I want to try is one of these cob hats (as much for the oven aspect as for the thermal mass), but I want it to be simple to remove for maintenance. Heavy and semi-fragile things are a pain to move. So I think I would need to build an A-frame and rig a hoist, probably with a block and tackle.

Awesome!

Tina Wolf wrote:I find it awe inspiring how a little bit of mud has such a large impact! This video shows how the "cob hat", aka mud, was added to the Minnie Mouse in the Love Shack. It is capturing all the heat that was rising, and overheating the top of the cabin, so it radiates over hours to heat the cabin up pretty quickly and keep it warm for hours.  They are so creative!

My garage is like a cabin when it comes to cold.  I've insulated it but it's still cold in the winter. The Minnie Mouse with the Cob Hat would heat it up quickly and keep it comfortably warm enough for me to get work done without freezing.