Bill Kielb

This might help It’s important to go the correct speed in the last 100c of the firing to achieve the expected heatwork, so whether worn elements, not enough power, stuck relay,, anything that extends the last 100c will have a dramatic effect. Prior speed, not so much.

My suggestion thin it with water until you find a nice thickness for your application habits. It looks applied too thick so how can you apply it thinner? Maybe think of viscosity as the internal friction of the fluid. The more viscous, the less likely to flow freely or (it’s thicker) So adding water or thinning definitely will reduce the viscosity or make it flow more freely. There are other reasons for crawling but your pictures indicate it was applied too thick. Before jumping into other remedies, maybe try the simplest by adding water till the glaze works for your habits. +1 for finding this ideal personal sg by testing and measuring the specific gravity and …….. marking it on the bucket.

It might be, compared to other products. Bricks are great outdoors, but bricks with a bit too much porosity, especially glazed bricks can be damaged by freeze thaw. Each product has the very same issue. So bricks made of clay, even ceramic faced bricks can last 50-100 years or or more with a proper installation and reasonable maintenance. So ceramic can be durable and comes in a variety of porosity levels as well as grout can be epoxy based and water proof. Is ceramic good for outdoors, it depends on picking an appropriate product, applying correctly to a suitable substrate, account for the environment exposed to, and routine maintenance of course. Lots of pools use tiles - pretty good long lasting solution depending on application, product, substrate, drainage, etc…

@Tova Cooper Just a couple thoughts - I suggest to make sure and cut it cleanly off the wheel several times to see if in fact there is an air bubble. You may need time to perfect your centering in the new environment and it simply may not be trapped air. Additionally rounding your clay into a ball ensures that the center will touch down on the wheel head and as you push down, air will be expelled as it seats on the wheel -:thrown or placed and pressed.

500 + 1000 grit definitely an idea. Sand / media blasting probably easiest way to get uniform. There are many blasting medias for different finish levels. I have used liquid glass etching for logos /initials etc… never on a whole pot though

@Dom_Llam Here is a generic explanation from an old Duncan wiring supplement that I believe was mislabeled on their website. I believe it is applicable to all models with the switch and timers. This may help

Heck the old nichrome element wire (Nickel / Chrome/ some iron) or even newer Kanthal are very resistant to corrosion and even when they do under operation, that small skin protects them from further corrosion. New in storage, probably shiny elements. Fired once then stored, pretty much ought not to matter actually. You might find some of the electrical contacts oxidized and maybe a critter or two that likes a dark place to hide in the control box. Post a picture or two here if in doubt.

Which equipment? Pretty long thread.

Not ideal for sure and slowing things down is a necessity as well as indirect heat. (No blasting flames on the pot) Bisque firings take let’s say 8-10 hours so the math there says 200 f per hour or less I think Glaze firings take let’s say 6-8 hours so again not more than 250f per hour. Thats a lot of minor gas adjustments. Might be doable for a one off - likely a pain to go that slow.

I would definitely find the lower temperature limit of this. To me it’s definitely melting and even running a bit so firing a cone lower in temp may be just the thing that reduces your pinholes and improves your color rendition. It’s not uncommon for some glazes to have a fired surface tension such that they won’t heal. Drop and hold schedules generally help solve this issue. Fading color, movement, pinholes, I would figure a way to test glaze fire at a lower temp and look for a trend.

Just a curious question, do we know what cone these ended up being fired to and if so have these been tested at a lower cone? Have not read all the above so if redundant - apology in advance.

@Sylvie @min and @mark have great points each! The one way to do this is something we teach at the wheel that can be done in your head. The exact solution as min mentioned is your starting dimension divided by (1- percentage shrinkage). so if you want some future dimension to shrink to a certain exact known size definitely divide by 0.88 - in this case for 12% shrinkage to equal your intended fired dimension. @Mark makes a great point in that everyone throws differently and 1.5 #’s gets him there. So depending on how you throw and your design requirements you may use more clay. Just a mention on precision - we used to have folks throw a tall bail wire locking canister just for fun. (bail wire lock and gasket free for the project). This project would make everyone really think and experiment with how to get all the stuff to fit precisely while also challenging their ability to throw taller. In the end, clay often does not shrink exactly some specific even number percentage so potters learn by experience where to increase their size or allowance a bit or create a practical way to throw with some extra room for proper fit of all things. In the photo below, the lid fit, wire fit diameter as well as spacing of the wire from the top made folks think a bit. Most after practicing found this was pretty easy with an attempt or two under their belt. It definitely made them realize with some practice this was something one could learn to do with a bit of practice.

They are very available. Match the loading voltage and amperage though. Currently yours drive relays so not much load but they are used commonly for heaters, stoves etc…. Universal models available 3600 W I believe or 15 Amos at 240 v. Universal come with shaft adapters, can be directional and include push to turn so for an exact match, get the replacement Paragon suggests. Otherwise it takes a bit of thinking but very doable for many.

No worries, your pictures match up really well as this kiln without the switch. Definitely need to be handy with wiring so wise to wait for your friend. If he looks at it and agrees I am pretty sure from your pictures and the drawing it will be easy to show him the issue and he can match the drawing and function. At least you will have a future option available.

I am with you - can’t tolerate most scents including perfumes etc…. I will say clays in general are not artificially scented. Mold is everywhere and anywhere waiting for food and environmental conditions to grow. For me good housekeeping and peroxide definitely have allowed my clays to stay colony free. As far as scent sensitivity - perfumes, dryer sheets, garbage bags …… air fresheners, just about everything artificially scented I just can’t tolerate and my only recourse is to distance myself. I used to drive past a proctor and Gamble plant everyday and sneezed for the next five miles. At least no ocular migraine I guess. You never know it’s definitely an individual response.

Good catch - bad math in my note! Neil’s right, top and middle combined fits the relay better at 25 amp contacts I believe. Or just add an infinite switch for middle elements and still disconnect the timer connections to the sitter. The middle relay is a normally closed so ditch the timers I think is easy or ditch the relay but jump out ALL the L2 connections to it, as necessary as if the relay is closed would be my thought. Fixed the drawing above too.

Sounds like desert climate

Euclids https://euclids.com/pages/kiln-elements likely can wind you elements and getting a small hook shaped pry bar (re purposed small screwdriver) in the corner between the covers could help you remove the covers without having to pry against the soft fire brick. All likely Brexit free.

one way - Pick a height or width you like put it in a volume calculator https://www.omnicalculator.com/math/cylinder-volume. Make sure the calculator is set to inches high, inches diameter, fluid ounces. Determine the shrinkage of your clay, let’s say 12% as an example. Then throw your mug by multiplying the design height and diameter to be 112% (1.12) so your mug ends up shrinking to the expected design amount. Comfortable and aesthetic diameters for mugs are approximately 3-1/2” -4” with 4” closer to a stein type vessel. A vessel that is thrown at 3-7/8” diameter and 5.5 inches tall likely fires and holds 26 oz and finishes about 5 inches tall and 3-/3/4” diameter after firing.. All that’s left is pick a nice handle and personalize! If I remember correctly, the mug below is about 4” in diameter and a touch over 5” tall and holds two full cans of beer (or soda) leaving room for a nice trimmed foot - maybe 1/4” or less.

The channels or grooves for the elements may be cut deep enough or at least two corners or two channels which could allow you to press two gently inward allowing enough clearance to remove the the first cover. Once one is removed in a row, the rest should come out fairly easily.

Actually better than I thought it would be. So propping the lid is another common way to slow things to dry them out, just an inch or two ( let’s say 2-5cm) to go slow through 100c. Just from the slope of the line, it looks like a fairly normal climb rate. So a loaded kiln start with top switch off and bottom minimally on (11:00 O’clock) prop lid for first hour, then close lid, turn top switch just on, say 11:00 o’clock after three hours. You might be able to make useable. Neil is right though, those relays IMO are not worth it and I just convert these to all infinite switch operation. Often can re- use the top and bottom switch and get by installing just one additional infinite switch though. This does require you to be handy though. BTW - this is a fairly clear diagram I have that MAY apply to your kiln? Do you have a rocker switch somewhere for low, Manual, Auto? If you have this switch, then what position have you used this in? If this diagram fits your kiln, then you can place the center elements on the upper relay and jump out the timers fairly easy, in a pinch. Your kiln would only operate manually with the top and bottom infinite controls at that point. Just reviewing your picture, the center elements are on all the time your kiln sitter is, moving the center elements to operate from the top element relay will solve this and place it under your control. The timers should also be removed (simple one wire removal) else they may cause more confusion in operation. So fairly easy to try by relocating two wires and disconnecting one timer jumper I believe.

450c per hour is definitely rocket speed. Something easy to try: With the top switch off (12:00) and the bottom switch turned just on or pointing about 11:00 (just a slight turn counter clockwise) how fast does this thing fire to 500 c? Speed is often is a common issue with this style kiln and is often the result of the timing relays. It can be operation though as the temperature controls operate a bit backwards from what folks are used to. Here is a thread that may help https://community.ceramicartsdaily.org/topic/17923-help-with-using-a-duncan-automatic-teacher-plus-kiln/ as well. Post a picture of your equipment tag showing model, etc…. The problem with this, the timing relays are very expensive and at this point really hard to come by so diagnosing is difficult but usually necessary as opposed to just swapping parts.

There is a good chance you simply have a Cress kiln, they still provide documents for their kilns.. This likely is your wiring diagram https://cressmfg.wpenginepowered.com/wp-content/uploads/B18H-240-VAC-1.pdf and this would likely be your manual https://cressmfg.wpenginepowered.com/wp-content/uploads/BASIC-KILN-MANUAL-FOR-ABC-KILNS-1.pdf. If you post the picture that @Dick White mentioned we could confirm. If that is your kiln, as the diagram says, you will need a 3 wire 240v circuit protected by a 30 amp breaker and #10 copper wire for normal distance power runs.

I think sort of like a golf swing. If it works for you and you can repeat it ……..

Not sure this helps I can say I always used a three second dip, so everything I make has to accommodate that. I can also add several years ago I was at a John Britt workshop and while dipping a tile we were both counting one one thousand, two one thousand …… we both laughed. Not speaking for him but he seemed used to my three second dip and it made me feel better about my dipping practice. My base reason, if I wait too long my stuff becomes water logged. Same with pour in and pour out, fill it, pour it out and roll the rim even while pouring. About three seconds. Always bisqued to 04 as well.