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Washing Kiln Shelves


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#1 AndyL

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Posted 13 April 2012 - 11:37 AM

I'm a realitively new kiln owner. My L&L (e23T, Computer Controls) fires like a champ. I've had "Mrs Potts" for about a year now. The kiln shelves at this point are heavily crusted with kiln wash and the kiln wash is alligatoring badly. Normally I just get off this mess with a Silicon Carbide Rubbing stone. I'm wonderig if there comes a time when it pays to totally remove the layers by washing them off and start from scratch? Any thought on this? I don't want to risk damaging the shelving in any manner. Thanks

#2 neilestrick

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Posted 13 April 2012 - 12:00 PM

At some point you'll need to clean it off and flip them over to prevent warping. If they'll scrape off, great. Otherwise you'll need an angle grinder with an abrasive disc or a diamond wheel. You can cut into the shelf, so you have to be careful.

Neil Estrick
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Owner, Neil Estrick Gallery, LLC
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neil@neilestrickgallery.com


#3 Idaho Potter

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Posted 13 April 2012 - 03:16 PM

When you have a prolonged period before you need the shelves in the kiln, why not wash them off? I've taken mine and attacked with the carbide scrubber, and then used a hose (trickling) and a stiff brush (wire if necessary) and scrub 'em clean. It takes many days to dry, and I run them through a 200 degree preheat for several hours a couple of days before I need them. It's always satisfying to start a glaze firing with smooth newly applied kiln wash--almost as good as a new kiln.

The only time I use a grinder is if glaze ends up on a shelf.

#4 Marcia Selsor

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Posted 13 April 2012 - 03:39 PM

I use a wire brush to knock off flaky parts. I use a grinder if there is glaze. Idaho Potter's idea os washing them is really a good one, especially the heat drying to assure they are ready for a firing.
I like that.

Marcia

#5 JBaymore

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Posted 13 April 2012 - 04:32 PM

If you happen to be using Advancers (St. Gobain), you'd do best NOT getting them really wet. They like to explode in the kiln if they get wet and you do not dry them VERY slowly and VERY fully. Many wood fire potters have learned this the hard way...... including myself.

best,

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#6 Darla

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Posted 13 April 2012 - 08:16 PM

I'm a realitively new kiln owner. My L&L (e23T, Computer Controls) fires like a champ. I've had "Mrs Potts" for about a year now. The kiln shelves at this point are heavily crusted with kiln wash and the kiln wash is alligatoring badly. Normally I just get off this mess with a Silicon Carbide Rubbing stone. I'm wonderig if there comes a time when it pays to totally remove the layers by washing them off and start from scratch? Any thought on this? I don't want to risk damaging the shelving in any manner. Thanks




If you have access to a decent sized air compressor.... try using an air grinder, with a flex disc, 36 grit. It's actually meant for Auto Body/Paint repair work. The sanding surface is very flexible, not hard. Doesn't take ANY of the shelf - just the wash and glaze. It takes very little time... The last time, my husband took 2 full shelves, and 6 half shelves down to the bare shelf in 30 minutes! However, please protect yourself.... the kiln wash flies off in chips with LOTS of dust.

Darla



#7 Kabe

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Posted 13 April 2012 - 11:11 PM

might mention ( for potters that are just getting started) that the glaze on the shelf that is left over from a drip or a run can be sharp as a razor blade. I ran my hand across a shelf one time to just whip off some dust and found this out the hard way and I even knew better, just wasn't thinking. It pays be careful if your scrubbing. Happy firing Kabe

#8 AndyL

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Posted 14 April 2012 - 01:08 PM

Thanks everyone for your thoughts on this. You've all been a great help to me.

#9 perkolator

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Posted 18 April 2012 - 05:08 PM

what recipe kiln wash are you guys using that's hard to come off? or are you just letting it get really messy before cleaning?

for electric kilns, we use a 50/50 EPK to Silica - it works great and flakes off easily for a clean slate. it'll peel up if you get it built up thick or put too thick of a coat, but we usually just scrape them fairly clean and rewash at least every other firing. for cleaning up shelves I usually get away with a wide putty knife or carborundum rub brick and cold chisel for glaze spots. the difficult glaze mishaps or things that make it to the shelf get an air grinder with a 4" grinding cup head if I can't chip it off with the chisel.

our gas kiln wash is 90 alumina, 10 EPK, then add in 2% macaloid/bentonite and 1% CMC to keep it in suspension and make it nice and stinky :) this wash stays intact and doesn't flake up. we typically don't remove this wash unless something makes it though to the shelf or if a chunk comes off and makes an uneven surface - then i'll just sand it down with a rub brick or down to the shelf if need be. even then, it's not hard to take off unless glaze fused it on.

either way, if glaze gets on the wash - we remove it EVERY TIME. I have a nice trophy shelf that an unchecked glaze spot eventually ate all the way through to the other side and dripped!




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