Wood Kiln

The wood kiln is nearing completion. It is looking pretty good and I'm pretty happy about it so far. Here are a few random thoughts about the kiln building process to date.

Plans are good but don't count on following them to "the letter." It ain't gonna happen. My original plans that I drew up don't look like this kiln at all, except that it is 8 feet long and the walls are about 24 inches tall.

Fire bricks are not the same size. They might look like it and might stack nicely on pallets but they definately aint the same size.

Assume from the beginning of the project that you're going to be a brick short. That goes for mortar too. If you're cutting brick, you're going to cut a bunch of them wrong. In fact, just think that you don't have enough of everything on the purchase list to complete the project.

The next step for this project is to purchase some insulating material for the arch and the sides of the kiln. I am thinking about about a home-made mixture of Diotomaceous Earth and Fire Clay, four parts to one.

After work today I am going to light up a fire in this puppy and see how it works. Basically I am just going to play around with the inlet flues and see how the chimney drafts.

Tapered Chimney

It doesn't look like I got much done yesterday, looking at this photo, but at least the taper of the chimney is complete. Well...maybe. right now the opening is 7 inches deep by about 15 inches wide. I'm thinking about adding one more tapered layer of brick to make the interior measurments of the chimney approx 12 inches by 7 inches. I'm not sure how tall the chimney is going to be and I have a few options.

Option 1: I could just use more fire brick and build a nice looking stack. Option 2: I could build up a couple more courses on the chimney using brick and then just place a chimney flue on top of that. The chimney flue is 24 inches tall. And Option 3: I have a 6 foot piece of stainless steel pipe that is 10 inches in diameter. I like the brick idea best but we'll have to see how tall I need to go to create the necessary draft for this kiln.

Anyway, the weather was miserable yesterday, about 90 degrees and wicked humid. I think the dang heat was making me stupid as I cut a lot of bricks to the wrong sizes and even mortared on layer of the chimney without tapering it. Nasty weather. The next step on this project is to start on the insulation on the outside walls.

Wood Kiln Chimney Flues

I'm getting closer to finishing the mortaring. Here is the chimney and flues. One mistake I made was that I did not tie in the first layer of bricks that sit atop the flue brick into the walls of the kiln. I say "Just deal with it."

The measurements at this point are: inside is 23 inches wide and 18 inches tall. The chimney is 8 inches deep and 23 inches wide. This is the point where I am going to start tapering my chimney to get to a 9 by 9 inch hole.

The flues are 7 inches tall. The center flue is 2.5 inches wide and the others are 1-3/8 inches. I didn't follow any principles from any books regarding flue size and intake holes. I just built them based on photos I've seen of other kilns and figured better too big than too small.

Today, if the rain holds off, I hope to finish the tapered chimney and the front of the kiln.

Wood Kiln Construction

Changes, changes, changes. I spent the last two years bugging people about kiln design and construction, looked at bunches of books, plans, etc.....and have come to the conclusion--If you want to build a kiln "JUST START BUILDING!"

I'm serious. Nothing goes according to "plan" and if you stick to that plan and are convinced to follow that plan and make it work---well, more power to you. Its just a big headache. In fact its just a pain in the ass. Have an idea and just start building and solve the problems as they come up.

In this case I've finally started mortaring the brick. Mix is one part sand, 2 part fire clay. I've never really mortared brick before so I took it slow mixing up very small batches in a 5 gallon bucket, although I only mixed about 1/2 gallon of mortar at a time when I first started. Stuff drys fast and I was by myself--a true tyro.

As I was saying. Just build it. The dimensions have changed everytime I put them on paper. Once the bricks were stacked and mortared my dimensions are: 32 inches wide and 81 inches long (outside dimension). Ware chamber is 18 inches tall in this photo but will be 20.5 inches, and 23 inches wide when complete, (approx 9.5 cubic feet). And its 35-1/2 inches long. The fire box is 24 inches long by 23 wide by 20-1/2 inches tall.

I'm still planning on one-inch thick kiln shelves for the roof, layered with soft brick and fiber on top of that.

Still working on the front part of the kiln. Right now I am going to tie-in all the brick and create a door with some air holes in the front.

I should mention that the base is 36 cinder blocks and on top of that a bunch of house brick, then the fire brick. The exterior of the kiln will have a 2 inch layer of insulating material of some sort. Oh! and I did incorporate 2 peek-holes on each side. One in front of the fire box area and one higher against the back wall. I plan on using soft brick to fill these holes.

I'll post some info on the chimney and flues in my next post. But this is where I'm at, at the moment, But, everything is subject to change.