Hello All,

The summer is winding down at the Mt. Lebanon Shaker Village. My summer of "Hands to Work, Hearts to God" and forced abstinence is almost over. Leaving here is bitter sweet. It will be good to be back with the family but the weather in the Berkshire's is amazing.

Built my third lime kiln over the summer. This third kiln was based on the same design we have been using with a couple of modifications. Here is a listing of modifications and observations.

Kiln Version 3.0 (KV3.0) was lined on the interior with fire brick. Hard to tell if it made any difference. It probably did.

I modified the draft hole in the rear. This time the opening was the dimension of two bricks placed on top of each other, roughly 3"x8". This gave me enough room to push things around inside thekiln and also room enough to feed split wood into the rear of the kiln.

KV 3.0 was used for two separate burns. Curing out the kiln with the initial burn made a huge difference in the quality of the second burn.

In KV 3.0. I kept putting fuel to it constantly. As wood burned, I put more in. The kiln needed less fuel as it got hotter but as it burned down I still kept putting in more wood. Essentially I force fed it to see how hot it would get. Keeping a good flame shooting from the top of the kiln chimney is a good goal. Every 15 minutes I added more fuel.

I was concerned that the ash accumulation would can choke the kiln down, but I burned for 8 hours straight and still did not produce enough ash to gum up the works. Jimmy Price suggested that I burn pine next time since it burns hot, fast and leaves no ash to choke the kiln. I think that with our current design 10 hours of burning hard wood might fill up the kiln and cause issues. Since oysters only take about 8 hours for us...no problem.

I considered making the burn chamber smaller this time to increase heat but I like having a lot of room for air, wood and space for clean out. Making it much smaller would be a pain in the ass.

KV 3.0 is one brick width wider (4.5-5" with mortar) on all sides than previous versions. This did not add much material but greatly increased the thickness (50%) and heat retention. I also threw the sod we removed from the foundation against the base. What this does, who knows....

I placed two fire bricks in the front of the kiln grill to keep the shells from piling up near the opening. I have found that the front of the kiln is substantially cooler than the rest of the kiln and pushing the shells back further in the burn chamber results in a higher yield of well burned shell.

You need to be sure to stack the shells in the kiln so that air can move through them. Too many shells stop air flow and keep the kiln from getting hot. I placed two bricks on end on the burn tray and filled the kiln with shells around them. I then removed the bricks and it left two hollow "chimneys". I moved the shells around some during the burn and it was no big deal (except I fried my eye brows). I had to be careful not to do this after the reaction really kicked off or the shells started to crumble and fall into into the fire.

All in all things went very well. We burned 7.5 gallons of shell for 7.5 hours. During the last 2 hours the shells began to turn a translucent orange. Jimmy Price  told me that the red color indicates you are "in the zone". I was able to get a consistent temperature of over 950c for the majority of the burn time and at one point I measured a temp of over 1000c. The wind was blowing pretty strong and directly into the kiln. This helped substantially but my orientation of the kiln into the wind was blind luck.

I slaked about 1.5 gallons of these shells in an old flower pot. I crushed them with a hammer into bits a little smaller than a finger nail. I then added in enough hot tap water to create a dry hydrate. After adding the water things started off slowly with a base temp at around 100f. The temp continued to climb slowly but after a few minutes the mass in the pot began to swell and steam and the temp peaked at 210f. We made a fantastic dry hydrate that looked like feta  cheese. We added additional water at the end of the reaction and made a very nice, fat lime putty. I have over 4 gallons of unslaked burned shells left.

The shells burned well. The ones on the very top were sketchy (black looking) but the remainder burned well. It was easy to tell the difference between the "goats and the sheep". . So...the kiln  design seems to be very functional at this point. A few more burns with this configuration and we can look at some other more traditional methods.

The more I learn about this process the more I realize how little I actually know.....

Brian





Brian Scott Robinson, MHP
Professor
Savannah College of Art and Design
School of Building Arts
Historic Preservation Department
P.O. Box 3146
Savannah, GA 31402

912 525 6940 office (Tues/Thurs)
912 262 2650 home (students emergency only)
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