New Barrel for Rocket Mass Heater/Forge

I got a new barrel for my Rocket Mass Heater/Forge (RMH/F) from my neighbor. The new barrel is over 10 times bigger then the old one. This should give me a performance improvement.

The current barrel is too small to work, really. There is no room for the insulated heat riser they need to work. I folded up a metal sign to use for my heat riser. I have to cheat it by putting a pair of inline-duct blowers at the far end of the heater. This forces the draft to work in the direction I want it. Works well for the forge, it sucks all the smoke out of the building, not so good for a hot fire, I have to keep the fire a bit held back or I overheat the blowers.

There is a bit of math that is required to build one of these. Not too much though. Area of a circle is pi time the square of the duct diameter, all divided by 4.

I am using 6″ ductwork as that’s what I got for free on freecycle. 8″ would probably work better – that extra 2 inches gives me twice the air volume, but, I don’t have it. This gives me a cross sectional area of 28.2 inches. I want to keep this 28 square inches minimum throughout the length of the system. Especially critical are the areas around the burn tunnel. You can get bigger than this in places, such as with the burn barrel, but everything up to the burn barrel had better be pretty close to 28 inches or this thing will smoke.

The space between the top of the heat riser and the burn barrel is one of the few spaces where you can ‘tweak’. I guess going smaller will actually make the heater sound more rockety. I am going to try to maintain my 28 square inches. The circumference of my 6″ burn tunnel is 18.8 inches. So I need to gap the top of the heat riser from the inside of the barrel an inch and a half.

This is primarily a forge, so that means I need to forgo the burn tunnel. However, I can lay a dozen bricks or so and make a quick, loose burn tunnel for the times I am wanting to heat the shop to do woodworking, or some other project.

I want to be able to ‘peel back’ a few of the ‘layers’ so to speak, so I can show people how these things work. The barrel I got is conducive to such abuse. It has a lid with a bolt-tightened band to hold it on. I will make it so I can take the outer barrel off so I can show people the insulated heat riser inside.

So, All I have to do is cut two 6 inch holes in the barrel lid, balance the lid upside dine precariously on some uneven brick, and then somehow sling the barrel up over the top of the heat riser which tops out near 6 foot off the floor.

I have a hunch I won’t be taking the barrel off for show and tell all that often..

Keychain box

The contents of my pocket I carry a lot of stuff in my pockets. This is the contents of my left front pocket. I am tired of sounding like a coffee can full of nuts and bolts rattling around every time I take a step. My keys rattle against each other, the little Altoids tin, the pill canister, my knife, etc. I took to carrying the Altoids Smalls tin as a catch-all box due to it’s small size. I’ve had in my pocket for probably 4 months now, so it’s getting pretty tired looking.


Keys and an Altoids Tin I drilled a couple of holes in each corner of the lid of the tin. I picked the lid as the keys will cover the embossed Altoids name. Space the holes as near as you can to the outside but leaving a space for the base to fit inside of the lid and not hit the nuts. I used a couple of 1/2″ #6-32 machine screws and nuts to bolt the keys to the lid. I would probably use some of those Chicago Screws as they are called if I had them. I faced the teeth of the keys in, so they didn’t snag in my packet. I use the keys in a specific order, so they are ordered outside in in the order of use. I thought about using thin plastic spacers, but it doesn’t seem to be needed for now. I just rotate the keys out that I need. There is enough clearance around the keys that they are easily usable.


Keys bolted to an Altoids tin as a keychain You can see that the small tin, with 8 keys bolted to the top isn’t any thicker then my Victornox Cybertool pocket knife. Granted, that’s a rather large knife to carry every day.


My keychain can now hold stuff I didn’t want the keys falling off my tin. I super glued the nuts to the bolts and to the tin as I don’t have any lock-tight. A Dremel will take the head of the bolt off if I can’t break the glue with a screwdriver & a wrench.
I put my headphones adapter for my cell phone in the tin. I also carry a 1 gig USB memory stick in it that I made a custom, waterproof housing using some casting resin.
I am going to put a small bit of cloth in the bottom and lid to quite the rattle down. I will also put in a cotton ball to fill the space and help silence the contents of the tin as well.

I am going to see how long this tin key-chain lasts.

My New Crock Pot

My new crockpot with the lock-down lid, usable carrying handles and it's own spoonI went out and got myself a new crock pot. I rather like this one. It has 3 settings, High, Low, and Warm. It is designed to be hauled around even! There are latches on each side of the lid to clip the lid in place. It even came with it’s own spoon that clips into the lid!

The lid on my new slowcooker can be propped up like this, or it will hang vertically off of the handle tooA really neat feature is that the lid has little tabs so you can set the lid on one of the handles and it won’t go all sliding all over the place. I think this is a winner, I plan on using it a lot for the cooking club I am inPosted by Picasa