Jeffrey and fellow BPers, ,

We gave burning a rick a try and here is the story.

First, it was difficult in Savannah to get the proper mix of materials Jeffery
specified. Firewood is expensive ($225 per cord) and, of course, everything is
cut, split, and very dry. Also all you can get commercially is oak since most
folks don't want to burn pine due to the build up of pitch in their chimneys and
the subsequent possibility of chimney fire. As a result our rick was too small
(about 5'-6' in diameter and 5' high) and burned too fast (totally ash in about
6 hours). On the bright side, the circular design with the hole in the middle
worked great. The rick was never in danger of collapse, the shells continued to
drop into the middle as the rick burned down, and the burn was from the inside
of the rick to the outside. Packing the rick very tight in a spoke fashion kept
the free flow of oxygen from getting to the fire. One big problem we had was
that it was a windy day (5-10mph gusts all day) and this caused the rick to get
super hot and burn faster than it would have on a calm day.

We tried to slake the shells anyway and got nada.

Proposed for next rick burn:

Get a better assortment of wet and dry wood and build the kiln larger and closer
to Jeffrey's specifications. This will take more time to assemble and since we
are doing this burn in the middle of Savannah in a big field logistics of
delivery of material creates a big headache.

Questions:

How long and how hot is the rick supposed to burn? We have been working under
the assumption that we need to achieve 1000 degrees F for 10-12 hours. How hot
does a wood fire this size burn? Is there any problem caused by overburning the
shells? Should we get an infra red thermometer to measure the heat? Shooting a
thermometer directly at the fire seems pointless since the reading will be way
high. Do slaked shells react in a manner just like slaked limestone based
quicklime? I have never seen burned shells slaked so I don't know what to expect
as far as the reaction? I plan on taking some shells over to our pottery
department and burning them in a pottery kiln under controlled conditions to see
what results. I am looking at burning them at 1000 degrees for 10 hours. Does
this seem right?   

We also built a small kiln based on Gerard Lynch's plans for a small kiln for
comparison. Here is this story...

Our kiln was about 3' wide, 4' long and 4' high. We used modern hollow bricks
and lime mortar filling in everything as we went up. Unlike Gerard, we used wood
instead of coal to fire the kiln. It took a while (about 5 hours) to get the
kiln super hot. Reasons for this were that we were using oak and it took a while
to establish a good bed of coals and the kiln was very green so there was a lot
of moisture inside the walls that had to evaporate. The kiln developed a number
of small cracks due to the heat (we expected this) but the cracks did not hinder
performance. Looking inside the kiln we could see that the shells in the rear
were getting really hot (they were essentially translucent red) while those in
the front were cooler. On our next attempt we will try to do a better job of
evenly distributing the coals once the kiln really starts cooking. We had to
knock off at 8 pm  so the kiln burned from 9am - 2pm in a warming phase and
really burned well from 2pm until 8pm. We will try to slake some of the shells
tomorrow (they were left in the kiln to cool). We don't expect much since we
were only able to burn them at a nice rate for 6 hours.

Questions:

Once again, we need to get better info on how long and how hot to burn the
shells. The fun thing about the kiln is that we can easily regulate the
temperature. Does the size of the shell impact the parameters for burning time
and temperatures?

Overall, we learned a lot and we think we can easily work the kinks out of our
systems. I have seen several "interpretive" rick burns over the years but they
never actually produced anything usable. We hope to perfect our process so that
we can do a better job of informing the public as to how quicklime was actually
made on the colonial coast. Although I know it is possible, I have never seen an
oyster shell converted to quicklime. Any suggestions would be appreciated.

Photos and video of our rick and kiln effort can be seen at
http://www.myspace.com/professor_robinson . Keep in mind that the first videos
of a rick burn on my site are from a NPS "display" we saw in October.

Thanks,

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)
[log in to unmask]


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)
[log in to unmask]

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