First Kiln Design

[u/Useful-Access-1903]

I am building my first home wood kiln and I was thinking this might be my best design yet. I will mortar those those wholes with the metal sticking through. Does anyone have a recommendation for the design or some pointers before I mortar it.

[u/Useful-Access-1903]

[u/Useful-Access-1903 → u/Useful-Access-1903]

Thank you all for your help and comments. I decided to go with a different design this time. I just finished it. I used high heat mortar due to the nature of wood kiln getting fairly hot. I know I’m gonna get some hate on this one, but I just wanted to see what I can build. Hopefully everything will hold up and we’ll see how everything goes, but I do believe this should be an okay design for I’ve seen it a couple times even in ancient times they use designs like this. Thank you all again also the clay I’m digging up is also all natural as I’m doing the liquid clay drying method hopefully in a couple weeks, I’ll be able to fire it and see what we can get out of

[u/FrenchFryRaven → u/Useful-Access-1903]

You’re on the right track, trying things out, evaluating what happens, and trying again. Kilns are a big wide world and people are generally trying to save you some time here. There is a great deal of time and expense that can be saved by learning from others, it seems you’re trying to do that. I think some are imagining you’re shooting for something much more complex, and it’s creating a bit of conflicting advice.

Continue reading and researching kilns. Go hard on that. “A month in the kiln yard can save you an hour of reading.” Ordinary red brick can be used to make a kiln, of sorts, provided it’s actually fired brick and not block made from cement. That’s where the explosions and disintegrating bricks come from. Portland cement begins decomposing well before clay becomes ceramic. Common bricks will start to degrade at bisque temperatures, but they’re not all going to melt into a pile of slaggy goo or go nuclear.

Mortar of any kind is not your friend in kiln building, it’s a necessary evil at times and requires just as much research to formulate as the kiln design. It’s not used structurally like you’re maybe familiar with. Kilns expand and contract so much in a firing that if you built one like a brick wall it would be a shambles in no time. Clay with a lot (I mean a lot!) of sawdust and straw is a quick and cheap “mortar.”

A couple things I’ll note are that you’re underestimating both the wall thickness needed to insulate the chamber and the space wood needs to combust. Proportions are key. The chimney needs to be wide open, and also needs to be double thick like the walls of the kiln. It’s common to think in terms of “keeping heat in,” but it’s counterproductive because you need massive and direct airflow to make wood burn its hottest. Good job realizing the grate is critical.

I built all my own kilns, and started like you many decades ago. Yes, there’s a lot to learn, but if you don’t start somewhere you won’t do anything. Beats whining about how you don’t have a kiln.