Eino Kenttä

How about a mixture of pine tar, linseed oil and turpentine? It's the traditional thing for treating wooden boats in Sweden, and sometimes used on the exterior of houses as well. The wood gets a beautiful warm brown colour (though I suppose the exact colour varies depending on the exact mixture and type of tar) and smells nice. If you google "roslagsmahogny" (the name of one specific mixture) you'll find pictures of what it looks like.

I went wwoofing at a farm a bunch of years ago, which had goats. I'm a plant nerd, and the area was new to me, so I paid attention to what grew there, and what the goats ate. As far as I could see, they ate everything... with one exception. They wouldn't touch the local species of hellebore. Go figure. Hellebore is very toxic. They did eat English ivy, which is supposed to be toxic to mammals. Obviously, it's not toxic enough to goats to harm them, if eaten in moderation (it wasn't their favourite food, as I recall, just an occasional snack), while the hellebore would most likely have killed them. So it looks like they knew.

On the other hand, I have heard that certain poisonous plants, water hemlock for example, don't taste bad, so animals (including humans) will sometimes eat it without sensing the danger, and then drop dead. Water hemlock is also called cowbane... All in all, I guess the answer might be, as usual, "it depends".

Ooh, this is cool! Somehow missed this thread until now. Your meal looks tasty, makes me want to try!

I'm thinking that the time required to get to a full meal would be reduced quite a lot if you were to combine the foraging with trapping or some semi-passive fishing method.

The onion grass intrigues me. A thought: did you try to leach the tubers in ash lye or similar? People must have had some way of reducing the bitterness if they did eat them, and that's the first one that comes to mind. Can't imagine anyone wanting to eat anything tasting like you describe.

While I don't actually know as such, here's my best guess: it depends which specific salt the minerals are part of at the moment. For instance, potassium in ash is in the form of potassium carbonate (alkaline) or if the fire was very hot, potassium hydroxide (very alkaline). The corresponding acid of potassium carbonate is carbonic acid, a very weak acid. The corresponding acid of potassium hydroxide is water, which is not really an acid at all. If there are stronger acids (like carboxylic acids) present, the potassium will be found in the form of less alkaline salts. Wood probably contains quite a lot of various carboxylic (and other) acids, so in wood, the potassium will not be very alkaline at all, and the metabolism of the fungi and bacteria decomposing a pile of wood chips will produce a whole bunch more organic acids. Fire, on the other hand, burns away the vast majority of the carbon in the wood, including all the carboxylic acids, leaving the more alkaline salts.

Glenn Herbert wrote:I don't think the top is the best location for a radiant panel, though; it would be sending heat up to the ceiling, not out into the space where people could quickly feel it. I would set an access panel into a face of the bell, to serve two purposes: instant heat directly to the room occupants, and easy access for inspection, maintenance and repair of the combustion core without having to dismantle brickwork. A steel angle frame anchored to the masonry, with a flat steel panel screwed into it, works excellently in my experience.

Hmm, that's true. Can you get a good enough seal around such an access panel without ceramic fiber or similar? Would like to manage without it, if at all possible.

Glenn Herbert wrote:I built my bell from old red clay bricks laid up on their sides, covered by an outer skin of cob (about 6"/15cm). I did use firebrick for the top third and ceiling; red clay brick may not last as long, but if given generous clearances to the riser top should be good for many years.

6" is the upper limit of cob thickness I would recommend, as that takes several hours for the heat to start coming through and heating the room. 4"/10cm would probably be the best balance for mass and heat transmission considerations.

Thank you! Good to know that it's doable.

I've also been thinking about making part of the roof of the bell (not directly above the riser) from metal, to get some immediate heat. Like William, I'm a bit sceptical about ceramic fibers, so I've been toying with the idea of using a sand-filled groove as an expansion joint. The idea was to find a box or other container made of suitably thick metal, cut it in half more or less, and set it in a brick or cob groove filled with sand. See picture. Any idea if this could work?

Ugh. Semantics. In my head, an "influencer" is exactly what they talk about in the article. Someone who influences people for a living, where the influencing itself (or the money they receive for it) is the goal, rather than trying to change things for the better. Someone who wants to change things for the better, I'd call... I don't know, an idealist, perhaps?

All semantics aside, I thought the article was interesting. Thank you for posting it!

Here is the thread about that build, with lots of good info. It, along with Erica Wisner's great post in this thread, reassured me when I was starting to despair over the possibility of building a rmh without very fancy, hard-to-get or expensive materials. (Note, though, that I haven't actually built one yet.)

This topic is very timely for me, since I've been pondering exactly these questions lately. Right now I'm thinking about a double-skin bell, with the inner skin being old red clay bricks (possibly set on their side, to reduce the number of bricks needed) and the outer being cob. Would this work? I'd like to minimize the number of refractory bricks needed, so would prefer to not have to use any in the bell...

Now that, right there, is taking a positive view on life! My seeds are all bug infested - yesss, free selective pressure! Congratulations on your sunny outlook and bugs.

Seriously, though, I hope your project succeeds in making weevil-proof corn. Please keep us posted!

Interesting question, to which I don't have an answer, but it made me think about this thread discussing large apple trees.

Otherwise, does anyone know whether other pome species, like pear or quince, can be used for their wood? My impression is that they tend to grow taller and straighter than apples...

Oh, and welcome to Permies!