Bob Jackson

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since Jan 06, 2014
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Recent posts by Bob Jackson

I'd love to do something like this. In the front yard there's a 3' post from a satellite dish I've been thinking of incorporating into one.

I don't see another vent so I'm guessing the door is never blocked completely but is there a 'partial' door?
7 years ago

Alexis Hamels wrote:Thanks for all the answers so far.
It becomes clearer to me what I need to do.

I'll take the information to a local stove-builder and see what comes out of it.
The wall is made of red brick. I suppose it conducts the heat well, so that it radiates on both sides. That's what I wanted to make sure.

Another concern is how much fuel it would need. I definitly don't want to have to feed it all day long.

As a nice first job, I should problably best build a small standard rocket stove and experiment with it. I can see that now.

Consider - the smaller the rocket, the more time it'll have to burn. And smaller rockets take more tending.

ETA: I wrote that thinking you meant 'small ... rocket stove' feeding the bell/wall, but on rereading I guess that's not what you meant.
7 years ago
Using water to dissipate and distribute the heat is a good idea. That would help keep the sap pans from having hot spots.
7 years ago
If you do away with the coil you're moving away from the double boiler. It could be OK if the pot is not closed - pump water into it and let it overflow. If the pot is closed and it gets low you might have a problem (bomb).

Having your flue gasses in contact with the sides of the pot gives a lot more area for heat transfer. The chimney probably improves draw but you could also set it up with an open top (with proper gap) instead. Go to and look at items 5, 8, 19, and any others that may catch your eye.
7 years ago
First, the 'double boiler' method is much safer. In your pic I see a couple things "less than optimal". The inside of the heat riser is not the place to take heat from. Let the combustion complete or you'll get soot and/or creosote in the rest of the system. And your water flow is backwards, you want the cooler water in contact with the cooler gasses - flowing hot water past the cooler gasses is not productive. But exposing the piping to the intense heat makes things critical. Pump failure is not an option, the water will flash to steam and likely blow a pipe apart. Mineral buildup may become a problem, depending on your water.

This is the best setup I've seen:

Something like this:

could work with a coil in the pot, maybe put a J tube under the barrel and use a deeper barrel inside if you need more capacity.
7 years ago

Byron Campbell wrote:Yes I believe you've got a good handle on it Rob. The way the system is described in "the book", the two barrels are joined by their ends that would normally accept their removable lids (joined lip to lip with the standard barrel band clamp). So in your application one option would be to cut your top barrel to length with clamping end intact. Then close the cut end with a welded on lid, or even make one from a disk of heavier gauge steel for a nice heavy cook surface.

Here's another idea that may help you avoid the welding chore. Common 55 gal. drums have two molded in strengthening or stiffening bulges encircling their circumference, one at about 1/3 the barrels length and the other at about the 2/3 point. If the barrel was shortened by cutting it at the apex of one of those molded in bulges it would make for a nicely flared opening to facilitate clamping to the other barrels lip. Best to try this out first with a scrap barrel.

As to the gasket to seal the two barrel sections together, Wisner mentions using fiberglass woodstove door gasket, high heat foil tape, then the original ring clamp (band clamp).

That's what I was thinking but it might fit better against another apex (cut the barrel just above one). The clamp has a V shape doesn't it? Been a while since I looked at one.
7 years ago
Not much point heating under the rocket heater anyway, is there?
7 years ago
My insurance also says I have to have a UL approved woodstove. By the time I get one of those and a professional installation it will take a long time to break even. Value of the mobile home is about nil anyway, and my personal possessions are not documented. The main reason I keep insurance is liability, so if I do install a wood burning device I figure I'm on my own and I'm careful. They didn't give me fire insurance on the garage anyway.

I do try to follow codes where it's practical, but last time I installed a flue to code, the code changed shortly after.
7 years ago
I can't imagine a 0.4 carbon file being useful for long, even in wood. Files aren't specified for use other than coarseness AFAIK (you wouldn't want to use a rasp on metal in most cases but double and single cut work fine on wood). One that I recall reusing for a hot cut was a 1" wide Nicholson single cut mill file. Most wood tools are high carbon steel, with 0.4 carbon content you really don't get much hardening. I don't expect spike knives to hold an edge very well, and I don't bother with tempering.

Here are some spectro analysis of files, about the middle of the page:

"Rail anchors" make decent tools for some purposes.

Crystals VS grains in the structure of steel gets confusing to me sometimes. It took a bit of searching but I like this reference I found some time ago:

I'm not sure what you mean by most of the carbon being at grain boundaries or how they would be 'liquified'. At forging temps the grains are consolidating and growing, but hammering breaks them down. The carbon migrates around until the metal cools, and can get trapped within the iron crystals if cooled fast (quenched).

Looking around the 'net I can't find much pertinent, but it seems iron has a much greater 'affinity' for sulphur than carbon and it forms iron sulphide, which is a better explanation IMO. In this piece:

the 5th paragraph echoes what I was saying about the fire and 6th paragraph talks about the condensing smoke. I have seen that advocated as a finish. However when he talks about steel absorbing carbon from the fire I wonder. I think that lies somewhere between "unproven" and "wives tale" which smithing has more than it's share of. That's why I had wondered about absorbing sulphur.

7 years ago