mel jacobson on fri 28 jan 11
just to add to what nils wrote today. and some small
additions.
a well installed set of coils using itc 213 and 100 will
last almost forever. i know, i have done this dozens of times.
if they break, it will be at the connection in the red box.
you will note that when i take a kiln apart, i wash the
kiln. soap and water...and spray it with the garden hose.
clean it all up well. then let it dry overnight.
old electric kilns still work fine in most cases.
a good cleaning, check switches, clean connections
and tighten up things...it should be fine.
no reason to throw it away.
polish all connections so they shine. then tighten them.
both of my electric kilns are from the 60's. they work great.
my big one was a throw away. i snatched it off a friend's pick up
truck before she went to the dump. 1965 L@L
i took it all apart, cleaned it...in this case, i added new coils
as i had a set, itc'd the entire kiln and it fires like a dream.
simple/just high, medium and low. because of the itc i am
sure the coils will last for years to come. i only bisque in it
to cone 08.
in fact for just bisque, the non/computer sort of kiln is more
than fine. i control the ramp with an alarm clock.
cost. for me: hundred bucks. if you consider i had an old set of
coils, and itc was leftover...the cost: my time.
here is the original post to clayart for the gaselectric kiln:
or, check your old pmi magazines...it has pix..but this works too.
there are dozens of these kilns out in clayart land.
______________________________________________________
i have had some questions and thought i should
go over this again..esp since it is fresh from the building.
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 narro=
w.
or, stick the coils in a plastic bag, add the itc and shake and bake.
(itc is best if you use a blender, and blend the pee out of it for 6 minute=
s.)
it takes about a half cup of 213 to coat a set of coils.
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 thin coat of itc 100. thin coat is better than
a thick coat.
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 thin coat of itc100...make sure
it is all covered....well.
dry, then fire the kiln to cone 012 or so.
i then sprayed the entire kiln with a thin 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. you can stuff the hole with a
tiny bit of kaowool first, then spray.
buy a nice bunsen burner( propane) order from Frey Scientific.
connect it to a 25 pound propane cyl. rubber hose to a propane
connection ), then a clamp on the bunsen burner connection.
we installed a simple regulator.
load and start kiln...we staggered the pots on half shelves.
don't over pack, leave spaces...don't make dams for the flow
of heat.
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. we mounted
the burner on a broken kiln shelf...keep the flame about a half inch
from the hole in the kiln. don't stuff it in the hole. it takes great
engineering skill to figure out how to make the burner fit to the hole.
you know...broken kiln shelves stacked. (if you need it.)
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 held it there...as we had a great many
reds in the kiln. (down fire techniques work great, as you don't want
this kiln to cool too fast...be smart.)
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 totally 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 me 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.
we also surrounded the kiln with a piece of old metal roofing.
just for safety. the outside of that lkiln gets really hot at cone 10.
from: minnetonka, mn
website: http://www.visi.com/~melpots/
clayart link: http://www.visi.com/~melpots/clayart.html
new book: http://www.21stcenturykilns.com
alternate: melpots7575@gmail.com
Janet Moe on sat 29 jan 11
Thanks Mel,
Lots of great tips in here. I like the idea of putting the ITC in a bag wit=
h
the coils. I always enjoy your kiln stories. When we moved I totally
dismantled my electric kiln and packed it into boxes. It was an enjoyable
activity for me to rebuild the kiln in our new studio. I love to know how
everything goes together and works. I even reinstalled the old elements and
have gotten a years worth of firing from them. Each time I rebuild a kiln I
get a little braver and learn a little more. Always have clayart there to
help me. Thanks guys!
Janet, on Vancouver Island
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