Thanks for everyone's advice. I purchased Erica and Ernie's book, and I agree it was worth every penny, it would have saved me hundreds of dollars. I was excited to return from vacation on Sunday to work on the stove. I was planning on increasing the exhaust manifold opening to a 10-inch pipe that reduces to an 8-inch pipe as Caleb recommended and i was going to increase by heat riser to 54 inches. I was also going to cob the inside of my combustion channels to size them down to 7x7 and try to protect the 2000 degree hard bricks.
However, this is was I found when I returned, see below.
We just had 9 inches of really dense snow melt with an additional 1 inch of rain. the soil still seemed to try in the center of the greenhouse but it appeared like water was seeping in from outside the greenhouse. after a half hour of sucking up water, it appeared like it was going to continually seep in. for that reason, and also to better use the radiant heat coming off the barrel, and also to shorten my exhaust pipe which was a 55-foot straight run of 8-inch pipe which is longer than all recommendations. I decided to move the combustion unit 10 feet farther into the greenhouse.
while digging the new pit it became apparent it wasn't only seepage coming from the wet ground outside. but in fact, the water table had risen. since Im deep enough to reach the water table under moderately wet conditions I decided I need to raise the combustion chamber. I put down 4 inches of pea gravel to act as drainage under the system which I'm planning on running to a sub pump pit. I'm hoping I will not need to use a pump, but it will be available if we have more flooding. I put down 12x12in stone pavers to help stabilize the pea gravel bed and then added about 4 inches of vermiculite. i may try to fix the vermiculite with clay or a may create a pad of refractory mortar to float on the vermiculite bed, then do a layer of clay fixed vermiculite.
I also noticed that all of my firebricks had cracked after the first firing, and didn't think it was that bad but as I tried removing the bricks to move the firebox it turns out almost every brick had cracks.
I am not trying to find new refractory bricks in having a hard time finding a supplier near Chicago.
I need some advice, I'm tempted to try a cob core but I have seen a lot of casted cob cores seem to have a lot of cracking. I am looking at online suppliers of soft insulating fire bricks but some require you to order a whole pallet.
Does anyone know any suppliers in northern Illinois?
has anyone had luck with a cob core?
Do I want to use soft bricks or hard bricks, or a mix, hard in the feed chamber soft in the horizontal burn and riser?
What is the minimum heat rating on the bricks you would recommend?
Would it be easier to use the order ceramic board? would that burn out faster?
are there any good plans that would use 1-inch ceramic wool since I already purchased it? I'm having trouble figuring out how I would secure it.
my plan is to use an 8-inch duct vent for the chimney with a 10-inch pipe surrounding it with the gap filled with vermiculite has anyone tried anything similar?
if I can't find fire bricks I was thinking of building a plywood form of the channels that would be 7x7 and using a 2-4 inch layer of cob than brown construction paper, fiber blanket, paper, cob paper blanket, paper cob. knowing that the plywood and possible paper would burn out. Thoughts?