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Member Since 04 Oct 2011
Offline Last Active Jul 31 2015 09:55 PM

#80066 Burner Placement In Kiln Design

Posted by neilestrick on 25 April 2015 - 12:56 PM

Are you building the walls only 4.5" thick? You're going to have a mighty leaky kiln that way. Lots of joints open up when you just have butt joints like that. I would back up the bricks with a layer of rigid fiber board.

#80048 Burner Placement In Kiln Design

Posted by neilestrick on 25 April 2015 - 08:45 AM

The burner channels don't really need to be any wider than the burner openings, however you don't want the burners blasting right onto the ware. And I think you may need a bag wall of some sort, even if it's short. There's a chance you may not need one due to the small size of the kiln, but you should leave room for it just in case.


In a kiln that size I wouldn't mess with fiber at all. Build it with an arch and brick up the door.

#80013 Attaching Porcelain To Plexiglass (Adhesive)

Posted by neilestrick on 24 April 2015 - 03:16 PM

My rule of thumb is to use a mechanical fastener whenever possible. Adhesives will always fail at some point, unless they are made specifically for structural bonds. For instance, there are some architectural grade silicone adhesives that are approved to seal 2 pieces of window glass edge to edge, for a seamless appearance (I used to work for a commercial glass company), and even to hold glass windows in place. Adhesives for metals can also achieve incredibly strong, permanent bonds. There are some high end car frames that are held together with adhesives, because the bond is stronger and faster than welding.


But plastics- Plexiglas (acrylic), Lexan (polycarbonate), PVC (poly-vinyl chloride), HDPE (high density polyethylene (cutting boards)), nylon, etc. are an entirely different beast. We can glue two pieces of the same plastic together with a chemical adhesive that melts the plastic to form the bond with another piece of plastic. It's more akin to welding than gluing, though. The 'glue' actually evaporates away.  But attaching a different type of material to plastic is very difficult. Plastic is very smooth, and not at all porous, so adhesives have a very difficult time bonding with it. Even if you rough it up before gluing, you're relying on the glue to grab into tiny little cuts in the surface in order to hold. It's just not a strong bond. I have yet to hear of an adhesive that everyone agrees works well on plastics, which means that even if it works for you, it will likely fail at some point.


I have tried half a dozen different glues to attach plastic soap pump collars, and all have failed within 2 years, even those that people swear by. So now I use the cork stopper type.


I definitely would not trust silicone for long term adhesion. Notice how you have to re-caulk your bath tub every few years? It dries and shrinks over time, and loses its grip.


Ceramic pieces are permanent. They will last for hundreds of years or more. Use a fastening system that will last just as long.

#79984 Cost Or Running A Kiln .

Posted by neilestrick on 24 April 2015 - 09:00 AM

I have no idea what electricity costs where you live, but that seems outrageous and inaccurate. Most kilns in the US can be fired for under $15. HERE is a handy way to estimate the cost. My big 21 cubic foot electric costs me about $35 per firing to cone 6.

#79957 Water And Different Clay Bodies

Posted by neilestrick on 23 April 2015 - 07:30 PM

Different clays dry differently depending on their makeup. Porcelain dries quickly, because it is low in clay, which holds the water better than the other ingredients.


Pres, yes, the more humid the environment is, the higher the moisture content when a piece is bone dry. But I'm doubtful it's enough to require a different firing schedule unless it's really super humid, like it's in a root cellar with standing water on the floor, in which case a short preheat wouldn't hurt.

#79845 Ian Currie Test Tiles Forums?

Posted by neilestrick on 22 April 2015 - 09:34 AM

I make functional work, so I focus my efforts on food safe glazes. I guess what I'm getting at is that the grid can be used in a multitude of ways, to achieve very broad or very specific results. It's a wonderful tool.


I use Hyperglaze glaze calc software. It has a function where you can plug any glaze into the limit formulas and adjust them easily. 4 corners of a grid can be done in a matter of minutes. It even has a quadraxial blend function. I think glaze cal software is worth every dime. It's a great way to catalog your glazes, it saves a ton of time when working with formulas, and it enables you to see what's really going on with a glaze. Unity formulas are far more informative than recipes.

#79792 No Tare Beam ;-(

Posted by neilestrick on 21 April 2015 - 11:56 AM

If the seller won't accept the return, file a complaint with PayPal. They have a category specifically for 'Item Not as Described'.

#79735 Newbie Bat Help?!

Posted by neilestrick on 20 April 2015 - 02:05 PM

You shouldn't need a bat for anything under 3 pounds or so, which the exception of plates. It's good to learn how to remove pots from the wheel head. Bats are pricey, and take up a lot more room on the shelf. Not good when you get into making a lot of work.

#79733 Advice On Drilling A Larger Thermocouple Hole

Posted by neilestrick on 20 April 2015 - 01:59 PM

Yep, the bit will follow the existing hole.

#79583 How Often To Clean Your Kiln?

Posted by neilestrick on 17 April 2015 - 06:31 PM

I shouldn't tell you this, but I've got almost 1000 firings on my smaller kiln and I've probably only vacuumed it out about 10 times.

#79545 Glaze Squirt On Kiln Shelves

Posted by neilestrick on 17 April 2015 - 09:43 AM

Small spots on the shelf are likely from spitting, and can be caused by the boron. Large spots on the shelf and bare spots on the pots are different. When the glaze pulls away leaving bare clay we call that 'crawling'. It can happen when glazes are overlapped if the second dip is applied when the first dip is still too wet, or too dry. It can also be caused by the surface tension of the glaze during the firing, glaze thickness,  firing parameters, etc. Floating blue can be prone to lots of different problems, including crawling.

#79417 Turned Foot Rings On Mugs; Elegance Or Affectation?

Posted by neilestrick on 15 April 2015 - 03:49 PM

I turn a foot ring into almost every pot. I think it shows a level of care in the maker. A couple of forms that I make don't allow for it because I simply cannot turn them over to trim, but most do. I do not necessarily define a raised foot on the outside of the pot, but I do trim a foot ring on the bottom.


Rayaldridge, I agree with Mark that the foot on your mug is a little small. It feels like it would be tippy. In reality it is probably not, but it's all about proportions and perceptions. I think the handle is just fine, though. On a small mug you only need to get one or two fingers in it. I think a larger handle would overwhelm the form, and there's just not room for a larger handle without it being a big loopy thing.

#79281 Oxygen Sensor/probe - Commercial Vs Homemade Auto Sensor

Posted by neilestrick on 14 April 2015 - 09:28 AM

Like Marc said, the oxy probe will do nothing to help with evening out reduction. That's a kiln issue, and your type of kiln has lots of evenness issues. It could, in theory, help with over all efficiency so you're not reducing more than you need to, but that would only work with a kiln that can handle adjustments without throwing everything else out of whack.


When I reduce, I stall out the kiln so it's not climbing in temperature at all, and let it reduce for 45 minutes. Then I put it into light reduction and start climbing again. With your kiln, I would go very slowly up to body reduction to try and keep the temperature even, then reduce the crap out of it, stalling it out. In a kiln that size it shouldn't be too difficult to get reduction throughout the kiln if you stall it out.

  • Diz likes this

#79070 Pottery Add

Posted by neilestrick on 11 April 2015 - 10:18 AM

Or, as I tell my students, shut up and throw.

#79012 Pottery Add

Posted by neilestrick on 10 April 2015 - 03:18 PM


I think one of the hardest things to do is to focus on just one thing. The older and wiser I get the easier this is becoming.

You have to know your limitations. I love all of the interesting glazes that you glaze gurus can come up with, but my heart is not in 600 fired test tiles.

I know mine either. The problem was changing from cone 10 reduction to cone 6 oxidation. We moved from Oregon to North Carolina and my gas kiln rattled to death on the trip. It is hard to get gas in NC and we have been living in a rental for five years.

 I am not dead yet and refuse to give up!!



(aka Maddmudder, aka Bethbw13

Had some serious puter problems)



I made the switch to cone 6 oxidation about 7 years ago, and wish I had done it much sooner. I do not miss reduction firing at all, and find cone 6 to have many more options for color. The other nice thing about working with electric kilns is that I can run glaze tests in my little baby test kiln rather than waiting for the big kiln to fill up. That just wasn't an option when I only had a big gas kiln. I can fire several tests a week now, and develop a glaze in a couple of weeks instead of months. The transition was definitely stressful, but it was also a lot of fun to jump into something new.


Firing gas is definitely more romantic than pushing the 'On' button, and there a few things that can be done that won't work in an electric, but for most people it's just not practical any more. Building codes have made it all but impossible to do anywhere other than a commercial setting or an unincorporated area. An even then, there's a lot of hoops to jump through. Although I was already strongly considering making the switch to electric kilns, I was ultimately forced to do it when I had to move my shop. I just couldn't find another commercial space that would allow me to install my gas kiln, or one in which it was affordable to run the gas line and venting system.


Sorry to hijack the thread!