mel jacobson on sat 14 jun 08
this is the sane alternative to firing and reducing an electric kiln.
i have at least 15 testimonials from folks that have built them, use
them, time after time.
it is an outside, sheltered kiln idea. not in your living room.
it must be well vented.
an older kiln works well. i have fired the one we have several
times to cone 11. the gas seems to really kick the temp in the ass.
some have made very expensive, fine alternatives.
really fancy..and they work well.
so here is the story...as it appeared in cm.
gas/electric kiln.
as taught to me by nils lou.
take one electric kiln.
take it all apart...clean it very well.
brush out all the debris, and wash it.
yes, wash it....brush and water. rinse with a hose.
hard.
drill an inch and a half hole in the bottom center of the kiln and the
lid of the kiln.
order new coils, (euclids would be easy) or the originals.
clean them well with bleach, use a toothbrush.
coat the coils with itc 213 metal coat.
follow itc instructions.. i used a tray for sheet rock mud...long and narrow.
or, place the coils in a heavy plastic bag, add about a quarter pint
if thinnned itc 213 and shake. (i thin with water and use a blender
on high for six minutes. reallly blend it.
hang them to dry.
wet the inside of the kiln with water..use your sprayer.
spray the entire inside of the electric kiln and the channels for
the coils with an even coat of itc 100.
let it dry.
install coils as to original instructions that came with the kiln.
re/install and check all kiln sitter parts.
make sure the fittings are tight and clean...sandpaper the connections.
make them shine.
spray the entire kiln, coils and all with a coat of itc100...make sure
it is all covered....well.
dry, then fire the kiln to cone 08 or so.
i then sprayed the entire kiln with a coat of itc296a top coat.
let it dry....make sure you spray the holes full that carry the
coils to the outside of the kiln...don't want reduction leaking
out the coils into the electrical.
buy a nice bunsen burner( propane) order from Frey Scientific.
connect it to a 25 pound propane cyl. rubber hose to a propane
connection (pol), then a clamp on the bunsen burner connection.
we installed a regulator.
load and start kiln...we staggered the pots on half shelves.
fire with electric only until you reach 1750F.
turn on the gas, light and place the bunsen burner under the
kiln so that the flame goes up the hole in the bottom.
place a piece of kiln shelf over the top hole a small way, move until
you get an inch or more flame from your spy hole on the side of
the kiln. fire this way til the sitter drops.
we fired to cone 10.
about 5 hours...the gas kicks it up fast...really works well.
turn off gas.
button up kiln...kaowool plugs in the top and bottom holes.
we fired back up at about 1750...as we had a great many
reds in the kiln. and fire down with the electrics to slow
the cooling.
open kiln.
nice red, shino, good body color.
typical stoneware reduction firing.
and a very easy project to make...took about two hours one day.
maybe two hours second day.
for the cheapos out there...do not try and itc coat old coils..it
will not work. buy new.
i would not do this with a beat out kiln....try and find a decent
used body....repair cracks and stuff first. you want a clean, tight
soft brick surface to coat with itc.
we used some thin sheets of kaowool as a gasket on the top
rim of the kiln...want that tight.
we fired in the barn, with great cross venting.
you should be able to use standard electric kiln venting.
but, take care, use your head....it will fire hotter than
you are used to...and the reduction must be vented.
we put a piece of kaowool over the hose under the kiln
just so it would not be heat affected. and we protected
the main electric cable of the kiln. you know, be prudent.
don't be stupid. protect everything with kaowool.
and we used a nice piece of corrugated metal on the wall
behind the kiln. air space.
bob anderson mounted his bunsen burner on a brick...it brought
the burner right up to the hole in the kiln bottom. he added
a metal rod to the brick and can just pull it out when done.
in fact, there are many interesting things that sophisticate
this kiln. it just takes understanding of how simple everything is.
remember, you are lighting the gas and adding it to a hot kiln.
not very dangerous. and the bunsen burner is small...not like
a huge torch.
the best part of this project is:
you have a bisque kiln.
you have a cone 6 oxy kiln.
and you have a cone 11 reduction kiln. all in one.
nice. mel
from minnetonka:
website http://www.visi.com/~melpots/
clayart site:
http://www.visi.com/~melpots/clayart.html
| |
|
