Laura Kelly

Larisa Walk wrote:Our dryer design has worked in the humid midwest for over 35 years. You can read all about it at http://geopathfinder.com/Solar-Food-Drying.html

Larisa, do you still have a URL with your design? I have constructed a version based on your description, but would love to view a web page, and this geopathfinder.com link is coming up as a "page not found"

Down here in zone 7a, I have a small greenhouse with a massive north wall of rock and cob. I did not take care with sealing/insulation at build, and definately wish I had seen more ideas like yours. I did, however, know about rocket mass heaters, so I incorporated a little 6" system in the cob wall.  I usually only light it when nights are under 20⁰F, which has been a dozen or so nights so far this winter. After about an hour of fire, the ambient air temp will start to creep higher, and the wall will feel very warm along the line of the built-in flu. I usually run the rocket from about 5pm to 8pm, after which the cob wall will be uncomfortably hot in parts. The next morning, before sunrise, the wall will still be 100⁰F and the air temp above freezing. I certainly admire the potential for a more passive system, but I can say a rocket mass heater will keep the citrus trees alive. On the topic of overheating, down here in 7a, that is a year-around concern. I have Solexx brand insulated polycarbonate panels and some glass, and I open the panels on all but the most cloudy, cold days.

I built a cob house in humid NW Arkansas, and the only mold issue I've had is a slight spotting of the pale clay paint that I put over my earthen plaster each summer. (Then I would paint fresh in Fall).  Interestingly enough, the unplastered, unpainted walls of my cob greenhouse deal with even more humidity, and do not have any spotting that I can see. I put a bit of lime slip in my last batch of pale paint, upped the borax, and did not have any spotting last year.
The other humidity issue which I've written about in other threads, is the floor getting soft enough to dent in the heat if summer. Heavy maintenance oiling and a few throw rugs is the answer, I believe.

[quote=Steve Boyd] We have an All American pressure canner which is well used and I'd have no hesitation in using it in an institutional rocket fire and am confident that the heat could be managed with careful use in quantity and size of fuel.  [/quote]
I have a "non-institutional"rocket stove that I've used to cook my meals for 8 years. I feel I can manage the heat level very well both through fuel selection and placement of the pot. However, during the harvest season when I need to can, it is far too hot to cook indoors, so I use L-type wood burners on my outdoor kitchen. Managing their heat level for water-bath canning is do-able, but the canner is a sooty mess by the time I'm done. I wouldn't put a pressure canner over open flame for that reason, mostly. I have a used pressure canner that I have yet to use for lack of proper burner. I wonder if my old Coleman double burner camp stove would be up to the task. I suspect it would be slow, but able.

Saw a lot of folks in NW Arkansas on this thread. I built a cob home with rocket mass heater in Winslow, AR. I built an outdoor wood-burning oven and stove from cob as well. The only issue with humidity is that the earthen floor is softer in July and August. Pointy-legged chairs leave dents during those months. It could be that enough maintenance oiling of the floors would prevent the dents, but I've not re-oiled hardly at all. I've just gotten better at patching. Oh, also, our light-colored clay paint showed mold spots in summer. I added more borax and a bit of lime slip to a refresher coat, and that seems to have alleviated the issue.

Satamax Antone wrote:Laura, you might be missing some mass behind, and your draft is too strong. Maybe. Your firebox and burn tunnel still are made of bricks?

There is another thing which can do that, wet wood.

Ooo, damp fuel is a harsh teacher for sure. I have cooked and heated exclusively with wood for over 7 years now, and I'm still in love with fire. If there is one thing which I've learned:  use well-seasoned wood.  
As I write in my reply to Glenn, it appears lack of draw from too small of a burn may be my issue. Yes, the firebox and burn tunnel are brick, inside cob. Tons of mass in the bench around the exhaust. Old riser was especially massive, though, so it appears I'm just learning how to handle this lighter, more responsive one.

Glenn Herbert wrote:I have a cast refractory J-tube core and perlite/clay slip riser which is quite insulative, and coals burn to ash every time. I also have a positive natural draft, so if I don't cover the feed after burning I will get constant cooling airflow. I think you may be getting too strong airflow during coaling which is stealing the heat. Wood that is not dry enough could also be an issue, though if you have the same wood you used to that becomes less likely.

Right. When I had the more massive perlite clay slip riser, the coals burned to ash every time, and yes, I also had to put my feed tube lid on over night to damp. I've reached the opposite conclusion now, though, on the airflow. Now the air flow seems to stop on it's own, as the riser cools so quickly after a burn. Sure the mass bench is warm, but not enough to create a draw it seems. And my water kettle cools after a few hours, too. Result of such a light weight core.  I have a small barrel on my feed tube, and I use the lid to slow air flow and usually close it off almost tight at night.
I tried an extra long, hot burn  yesterday, and also forgot to lid the feed. I had much better results. Some ash formed and it insulated the still glowing embers all night. Kettle was even slightly warm.
So my conclusion is that the 5 minute riser lets me cook more quickly, and therefore I've been able to have shorter fires and still have a hot meal and warm house. But the riser is so much less massive that in order to store enough heat to complete a fuel burn, I should keep her full throttle for at least an hour.  

thomas rubino wrote:
Here is why , you are losing heat trying to heat up that big pipe and your combustion is not nearly as complete as it will be with a 5 minute riser.
What makes a 5 minute riser so good is the fact that it has no mass at all and funnels that heat directly to your barrel top and the into your mass.   Much less ash will get down into your system.

Finally some cold weather so I can run the RMH for a few hours at a time.  I do love the rebuild, of course, and the quick-heat cooktop. However, I do miss the way my old barrel stayed hot so long. The tea kettle always hot.    I also am amazed at how quickly my firebox coals cool down now. Coals used to continue to powdery ash in my former, more massive design. In the morning, the ash would be reduced to a cup or two in volume. If I'd had a bigger burn, I may still have a few embers underneath. Now, the morning firebox is full of a gallon of chunky cold coals, as if I'd doused them with water the night before. So many coals! I'm getting used to it, but wow!

Gerry Parent wrote:Laura,   I have read where some people have had success with controlling mold with the addition of borax.

Yes, it does help. This last time I added more than usual with no detriment that I can see. I even added a little lime putty along with the milk. Quite a concoction. Went on smooth. Dried tough. I have also tried leaving out the flour paste to reduce mold, but the result was not sturdy. Just dusty.

thomas rubino wrote:Hi Laura;
I give up... just what is an alis?

I guess some call it aliz, and most just call it clay paint.  I did end up ordering some of the bigger flakes for dramatic effect, but I wanted the super fine powder for milky smooth texture.  I doubt my ability to grind and sift as well as the clay supply stores. I'm curious to hear other folks experiences with clay paint recipes.  I've really enjoyed the mica flake recipe, though I have to give it a freshening coat each fall, as we have such high humidity here in the Arkansas Ozarks that some mold spots always forms late each summer.