Thanks again,
Scott

Smiles,

J

I’d recommend moving your re-bar up, closer towards the counter. With cob, like concrete, you have great compressive strength, but much less tensile strength, the reason straw is added in large amounts for overhangs for bookshelves. The re-bar looks to be pretty near the “neutral” plane which is the area that won’t stretch or compress much if a load (weight) is put near the outer edges of the counter. Below the neutral plane(arching lower side of the counter) will try to compress, while above the neutral plane (the flat upper side of the counter) will try to stretch to compensate for someone leaning/sitting on the counter or a heavy load (big pot of H2O) placed there. If the re-bar is moved closer to the top of the counter, it will help resist that tendency to stretch, and ultimately crack.

Better yet, you might use slip straw there and keep the extension less than 1 to 1, 45 deg angle out. The straw would give the firebox a little more insulation and probably have some benefit. Keeping the firebox hotter and bouncing that heat back into the oven, rather than letting it out when that lower part of the firebox is saturated with heat, as I’m guessing it will saturate much faster than the middle and top sections of the oven.

Just suggestions and thoughts. Appareantly you know what you’re doing with cob ovens. I’ve never built a single one, just done some reading on cob and studied some physics/structural engineering and am going solely on theory (we know how well that works out, haha)

Keenan

thank you so much for getting in touch, and for your kind words about my inadequate (but heartfelt) effort. I was delighted to find that the Wikipedia article I started had been re-written by someone so much better qualified and informed than myself, but couldn’t (easily) figure out how to post my gratitude on the Wikipedia contributor’s pages — or wherever it is you’re supposed to do that. (Getting the article posted felt like quite an achievement.)

You’re right about my lack of familiarity — I’ve only recently been introduced to Schuster and Carpenter’s work, partly through John Bishop, who (as you many know) did a documentary version of Dr. Carpenter’s book Oh What A Blow that Phantom Gave Me. I asked him for comment or advice on the Wikipedia article, but he’s busy and just encouraged me to put it up.

In any case, I wrote out of enthusiasm and delight. John and his wife Naomi own a copy of Carpenter’s Social Symbolism in Ancient and Tribal Art that they got from Naomi’s mother, who worked with Carpenter in CA. They have very kindly allowed me to borrow it, which gives me an opportunity to pore through the images, consider some of the ideas, and lament what we have (apparently) lost — or have we? They also told me about Carpenter’s health and his recent passing. I m grateful for what he left behind him.

And for you taking the trouble to comment. I will edit the post and encourage people to refer to the Wikipedia article.

I’ve also requested your book from the library, and will look forward to looking at it. What are you working on now?

Best wishes and gratitude from Oregon,

– Kiko Denzer

Regards

Mark