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Member Since 04 Oct 2011
Offline Last Active Yesterday, 07:59 PM

#127158 Opening Peep Hole With Vent On...

Posted by neilestrick on 24 May 2017 - 10:01 AM

Dry your work upside down.

#127137 Opening Peep Hole With Vent On...

Posted by neilestrick on 23 May 2017 - 07:50 PM

Putting pieces close to the lid will not block the flow of air for the vent. No worries there. However, leaving a peep hole open spoils the draft of the vent. The good news is that for the pots it's not a huge deal since leaving the peep hole open brings fresh air into the kiln, however it allows fumes to come out of the kiln and into the room, so it's not good for you. Leave the peeps in if the vent is being used.


None of the explosions were related to the vent, nor were they due to air bubbles. Air bubbles do not blow up. Air only expands about 1.5 times from room temp to 2000 degrees, which is not enough to blow apart the clay. Steam causes explosions. In the first 200 degrees of the firing, pots must evaporate off any remaining water in their walls before it turns to steam. Thick pieces aren't able to evaporate off all that water in a typical firing schedule, and when that water turns to steam it expands 1,700 times and blows up your pots. So for thick pieces you have to either do a preheat to dry them out, or fire much slower.

#126902 Mistake Made During First Firing - Left Top Peep Hole Plug Out.

Posted by neilestrick on 18 May 2017 - 03:05 PM

I did the same thing last night. Was firing to cone 5 but only had witness cones 5.5 and 6 available, placed on top shelf. Cones bent very slightly which verified it did not reach cone 5.5. The kiln computer temp says it fired at 2171 degrees, which is 4 degrees hotter than what my tech chart says is a cone 5 temperature. If the temperature was correct can I assume the fire was cone 5?


4 degrees is nothing to worry about. There's far more variation than that throughout the kiln.

#126779 Where Did This Yellowy Colour Come From?

Posted by neilestrick on 16 May 2017 - 11:03 AM

Yep. I've got several recipes for titanium yellows and oranges.

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#126609 2.5 Or 3In Fire Brick - Pros/cons?

Posted by neilestrick on 12 May 2017 - 12:42 PM

There is a noticeable difference in heat loss between 2.5" and 3" bricks. That's a 20% difference in thickness, which is significant. The 3" will be less work for the kiln to get to temp, which means longer element life, the electronics will stay cooler and last longer, and you'll notice a big difference in how much the kiln heats up the room during firings. Get the 3" bricks, get new shelves. Another option is to cut down your old shelves, which you can do with a masonry bit on a circular saw. It's dusty, but easy.

#126229 Waster Slab Question

Posted by neilestrick on 05 May 2017 - 05:25 PM

Neil did you take it up on bisque schedule till above danger points?
Pres, I too use grog but can see potential for fouling glaze on open ended ware.


No. Regular glaze speed. The slab was so thin that there wasn't really any danger of it blowing. Plus I was sure it was totally dry.

#126217 Waster Slab Question

Posted by neilestrick on 05 May 2017 - 12:22 PM

I think with flat bottom pieces you can use alumina, grog, sand, whatever, with success. But with open cylinders I wouldn't trust that to work as well as a waster slab. Plus I think the open cylinders are more likely to settle into the material when loading them into the kiln, possibly getting the material onto the glaze at the bottom of the piece.

#126201 Sybron Thermolyne Kiln

Posted by neilestrick on 04 May 2017 - 09:06 PM

Is it a manual kiln, with switches like lo-med-high or 1-6, and a Kiln Sitter shutoff? Those all pretty much work the same regardless of which brand, so you could download a manual for any manual kiln. Skutt, Paragon, Olympic, Evenheat, L&L, etc should all have manuals on their web sites. Also search the forum here because there are a tone of threads about manual kiln firing schedules.

#126170 I Need To Clarify Cones To Fire At For Brightest Colors

Posted by neilestrick on 04 May 2017 - 10:18 AM

First, for best results your clay and glaze should both mature at the same temperature. If you're using low fire glazes then you should use low fire clay. If you're using cone 5 glazes, then you should use cone 5 clay.


As for the colors coming out dull, it could be a variety of causes- the color of the clay, the firing, or the glaze. White clay will give you the brightest colors. You may need to try a different clear glaze. Make sure the firing is well vented.


If colors are fading at 06, then there's something wrong. Are you putting them on thick enough? Bisque temp shouldn't matter as long as you're in the 08-03 range.

#126105 How Many Cubic Feet Of Kiln Space Do You Use In One Month?

Posted by neilestrick on 02 May 2017 - 06:59 PM

I do both types of firings in all of my kilns. I wouldn't buy a new kiln without a digital controller. Digital used kilns are hard to find.

#126061 How Many Cubic Feet Of Kiln Space Do You Use In One Month?

Posted by neilestrick on 02 May 2017 - 06:45 AM

I always tell people to buy the kiln they'll need in 5 years. A kiln will last 20+ years, so you don't to buy something too small that you'll have to replace in 2-3 years, unless you're okay with spending another $3000 in the near future. The difference in firing cost between a full load and a 3/4 full load is very small, so it's not a big waste if you're not using the kiln to its full potential right away.

#126038 How Many Cubic Feet Of Kiln Space Do You Use In One Month?

Posted by neilestrick on 01 May 2017 - 07:36 PM

The first thing to figure out is what diameter and height she'll need to fire her work. It sounds like a 27" tall kiln, which is the most common, will work just fine. Figure 1.5-2 inches will be taken up by the bottom shelf, so she'll have about 5 inches to play with if she's doing 20 inch tall pieces.


Next is the width. Can she fit more than one piece in a 23" wide kiln? What about a 27" wide kiln? Would a square kiln of those sizes work better than round?


How many pieces can she make in a week? If she's making 8 pieces a week but can only fit one at a time in the kiln then she'll never get caught up on firings if she's doing bisque and glaze.


Can she lift her pieces into a typical top loading kiln? It can be really difficult to load tall sculptural things into top loaders. L&L makes a pull-apart option, where the controls are mounted on a stand to the side of the kiln so the rings can be easily taken apart for loading tall pieces- unplug the rings from the controller, unstack the kiln, put the piece on the bottom slab, put the rings back on. It works really well.


She may find that she needs to change her pieces a bit to maximize kiln space.

#126019 Getting Pitting In Commercial Glazes

Posted by neilestrick on 01 May 2017 - 12:44 PM

No, refiring won't fix that. If your kiln too that much longer than usual then there's something wrong with it. Check your elements and relays and thermocouples.

#125909 Peterpugger Mixers

Posted by neilestrick on 27 April 2017 - 08:58 PM

Claudia- It sounds like maybe your problems come from mixing the clay so stiff. If it's so stiff that the other brands of puggers can't even run it, then I'm thinking it may be too stiff for the vacuum to do its job well. And stiff porcelain doesn't mix very well. Because it's so non-plastic, it has to have a certain level of wetness for it to stick to itself and blend. Ever wedged really stiff porcelain? You just end up with layers that don't stick together very well. The same thing is happening in the mixer- it's pushing it around, but it's not sticking and blending well.

#125890 Quick Question: Sea Shells - Cone 6 - Which Type?

Posted by neilestrick on 27 April 2017 - 03:40 PM

Shells that are meant for display are usually boiled and then bleached, otherwise they start stinking pretty quickly. So all the salts will be pretty well gone and limit the flashing.