Bandy on wed 11 feb 04
DUMP)
I am considering an Olympic kiln and want to thank you for the great details
on firing.
THANK YOU!!
Cherie Bandy
dalecochoy on wed 11 feb 04
DUMP)
----- Original Message -----
From: "Paul Vernier"
Subject: Re: Need Info on Olympic "Torchbearer" and/or
I've been experimenting with this kiln and discussed it with Paul and a few
others , I also will make a few comments.
Regards,
Dale Cochoy
> I have had several discussions with fellow Torchbearer owners and I have
come to the conclusion that the following three things have the most impact
on getting even firings from this beast.
>
> 1) A dual thermocouple pyrometer. You must be able to see the temperature
variances any time after about 1400 f degrees. There are many on the market.
I use the Fluke and place a thermocouple in the top peep hole and the
bottom.
Ditto. I use dual fluke top and bottom and pay pretty close attention after
cone 06 body reduction. I find I can really even out top/bottom while doing
this and keep it pretty close until finished at cone 10.
> 2) The damper determines the distribution of heat as well as the flow of
primary and secondary air. Make VERY SMALL adjustments and watch their
effect with the temperature readings. But, don't react to the initial
reading. The changes can take a few minutes sometimes to have an effect.
Closing the damper (slightly) pushes the heat down, opening pulls it up.
Using the damper you should be able to get within 10 to 80 degrees top to
bottom, even in moderate reduction. Don't attempt to accomplish evening out
the temperature to early, red heat or later.
Yes, I use two small test kiln shelfs as my dampers and normally firing is
accomplished with a 2 1/2"-3" gap between the two pieces. Closed up pretty
close during reduction. I usually have 20-60 degrees between top/bottom at
finish of firing.
>
> 3) To take care of that last 10 to 80 degrees. Soak when your target cone
is just beginning to bend. Cut back on the gas and soak for an hour. Will
require a slight adjustment of the damper. This is a good practice for any
kiln.
> OK, 4) I do use the baffle shelf and will continue to. The distance of 4
inches off the bottom is also required. The stacking of the kiln is not real
critical, within reason. I have done some pretty creative stacks and still
had an even firing. I am not sure how much redirecting of the burners
contributes to even temperature as two of the three in my kiln go straight
up the side. I believe the baffle shelf has more impact. I use a 17" octagon
shelf placed 1 1/2 inch from the lid. Olympic no longer recommends a baffle
shelf. But, I will continue to use it as it makes a lot of sense to me given
the small distance between the outside of the kiln and the vent, less that
12 inches. A quick exit for the heat with little reason to venture into the
stacked ware. I think it would work without the baffle. But, I would have to
think it would be a longer firing cycle to your target cone.
Yes, I use 4" space at bottom and next firing I'll use the two burners flame
spreaders to help even top/bottom rise and reduction.
I use a 1/2-shelf from the kiln 12"x23" for my baffle at about 2-21/2" from
inside top opening. I could not get top and bottom anywhere near each other
without this. Top was ALWAYS MUCH hotter. I was 2 1/2 cones different. Now ,
using it, I'm only about 1/2 cone to one cone.
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