Craig Dunn Clark on wed 8 oct 03
=?iso-8859-1?Q?______Consecutive_firings?=
Wesley, I do consecutive firings for raku purposes on a regular basis.
Been doing so for the past 10 years. Just place the pieces that you want to
put in the next load arrayed around the EDGE of the lid of the kiln. If you
are using a clay body with basically "zero" shrinkage then the top
preheating method should be sufficient.
The difference between firing with the electric and the gas (beyond the
obvious atmoshperic differences) is that it helps to let the kiln cool down
a bit more before putting adding the next round of pots. The extent to which
this is necessary is based upon the thermal shock capacities of your clay
body, the type of pieces that you are firing (thickness,size, weight, shape)
and the types of glazes that you are firing. I've got a green crackle that
takes on a reptilian caracteristic (it mottles) if I put it into the kiln to
quickly.
When I say cool down a bit more I mean a low red heat at best,
especially if you are firing some larger pieces or any type of open forms.
Platters in particular. ONe thing that works well for me is to place soft
bricks in the kiln and to use as pedistals for the pots to sit on. They will
cool down much more quickly than the kiln shelf at the bottom or the rest of
the kiln. This takes some of the shock out of things thereby facilitating a
faster turn around.
As to the use of cones I do not use them for raku. I use the technique
that you have described in looking for a reflection from the surface of a
fluid mature glaze and also by the color of the atmosphere. I will segregate
some of the glazes that require a bit higher firing than the crackle ones
and really amp it up. I'll fire the alligator to a good 2000F for the best
results and the green crackle will take on a opalescent quality at a little
less. THe white crackle becomes to fluid at that temp and starts to run off
the pots.
If you have any questions please contact me off list and/or give me a call
Craig Dunn CLark
619 East 11 1/2 st
Houston, Texas 77008
(713)861-2083
mudman@hal-pc.org
----- Original Message -----
From: "Derrick Pottery - owner - Wesley Derrick"
To:
Sent: Wednesday, October 08, 2003 2:06 PM
Subject: ;Þ Question to the Electric Rakuist RE: Consecutive firings
> So far, since the purchase of my electric kiln, I have only done one raku
> firing a day, perhaps 3 to 6 pcs. only at a time....that was back in the
> day of trying to use stoneware clay left over from a college class and
> losing 60% of the load every time.
>
> I have now moved on to a Raku body with almost zero shrinkage and haven't
> lost one pot --loving it!- (but I miss that nice "ding/ring" when you
thump
> the pot after bisque firing)....anyway,
>
> I know for sure that IF had I dropped another load of glazed [stoneware]
> clay down in the kiln for a second firing right after pulling the first
> load, that they would have ended up an integral part of my bricks and
> elements within minutes....BIG BOOM.
>
> My question is...can I trust this raku body to withstand the already 1100
> to 1400 F degree kiln if I drop them in for a second firing?
> Do they HAVE to be pre heated....if so...how much.
>
> There's no real way to preheat the pcs of the second load being there's no
> flue to set the pots by --like a traditional raku gas kiln.
> Have I made any sense?
>
> Does anyone doing Electric Raku do consecutive firings?
>
> Would love to here from you.
>
> Wesley in Raymond , MS.
>
>
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