Hulk

The scorched looking spot doesn't look so good. Have you found any fuses? If so, is it burned?

See 10-SEP-2020 update, second recipe, "Min's low expansion III" Clay composition and crazing - Page 2 - Clay and Glaze Chemistry - Ceramic Arts Daily Community I mix and sieve it, setting specific gravity to about 1.42, then adjust the thixotropy as needed*. I like the glaze, having tried, adjusted, then abandoned several clear/clearish liner glazes before getting this one sorted. Playing around with new recipes in coming years, likely, for my bag of Gerstley Borate will one day be empty, also the bag of Texas talc, and smaller sack of Petalite. *I'm stirring clockwise at a repeatable speed. Once the whisk is removed, I expect to see the mass of glaze revolving together at the same speed, for about three or four turns before coming to a stop, all together, and "bouncing back" a little bit. Glaze that's not sufficiently "gel" will spin much longer, with several currents running at different speeds. See Tony Hansen's article and video clip Thixotropy and How to Gel a Ceramic Glaze (digitalfire.com)

Temperature can be measured fairly accurately*. For our ceramics, it's time and temperature, which is typically called "heat work." I'm about to head out for the day, will check in again later. *precision typically costs. For our kilns, consistency is likely more important than accuracy.

That glaze formula (ChristopherW, above) is within two percentage points of "Functional Clear" glaze (cone 5/6) that was available in a Studio setting where I started out. It went on well*, melted well - glossy, smooth, fit the clays, nice! ...however, I'm not seeing that it's particularly durable. The wares that have seen regular** use, the glaze failed, hence the wares were retired. I'm using a liner glaze that has much less boron, more silica and alumina, low coefficient of expansion... A nod to Forum regulars that provided feedback, observations, and formulation suggestions when I was looking to fit a liner glaze. I ended up abandoning a few (at least four) formulations and adjusted what I'm using now several times. *After thorough stirring, I'd ladle some out to a clean container, sieve it, check specific gravity, adjust the thixotropy, glaze my ware, then dump the glaze back into the communal bucket. **The wares that see occasional use and are otherwise "babied" by hand wash with mild soap and No Soaking are still looking good.

Good questions. Good to be back at it too! I had some big gaps over the last fifteen months, ramping back up lately. Given your pyrometer gives consistent readings, you may be able to get very close to the desired heat work by correlating the temperature and time to the cones' bends. Your goal, very likely, is "heat work," not so much temperature. A kiln that heats up quickly (over the last hundred degrees or so) will either run up to a higher temperature, or hold at peak temperature, to bend the cone, where a kiln that heats up slowly at the end will bend the cone at a lower temp. Pyrometric Cone (digitalfire.com) Some atmosphere exchange is likely good, allowing fumes to escape and oxygen in. Likely one peep open - typically the top one - not all. The heat, especially once past low red (cone 6 is light orange to yellowish), is getting to your wares almost all by radiation, very little convection. Expect that there will be hotter and cooler areas in the kiln. This can be mitigated somewhat by: loading the hotter areas with more ware, shelving, and posts (iow, mass); loading the cooler areas with less ware - tall is good, for shelves are very heavy; manipulating the controls. My first kiln, fitted with a sitter, was controlled by three switches, each with off, low, medium, and high settings. First firing, way overfired. Subsequent firings, I watched cone packs set by the peep holes*, took notes (times, temps - via brand new pyrometer, switch changes, final results) and tweaked the setter until it was fairly close. After several firings, I was confident that reading the pyrometer was sufficient, however, I continued to place cone packs in each firing and note results. I bought the portable pyrometer Skutt sells (it's a TPI 343** ) I never did trust the setter to shut down when just the amount of heat work I wanted was achieved. The setter mechanism, to me, is a failsafe, which will shut the kiln down (either by the cone melting, or the timer expiring) in the case I fall asleep or somewhat***. That said, there are many potters that trust their sitter and get good, consistent results. See online tutorials for repairing, refurbishing, and adjusting your sitter. *kiln glasses are super important for protection against harmful rays and any superheated flying bits! !! ** 343 Dual Input K-Type Thermocouple Thermometer with Field Calibration | TPI USA (testproductsintl.com) ***I'm also watching the new kiln, which is fitted with three zone automated firing control, and taking notes.

On the left, 600g (~1.3 lbs) mug. A normal/medium mug for me, 350g, however, as the large and extra-large ones, people pick them up, 600g is now "medium" size. The turquoise plastic tumbler is handy as a "rounder" - the taper fits most mugs, and the shape is, strangely ideal.

Looks like the J230 was spec'd as GrayB indicated*. The voltage, aren't most homes supplied with 240v? Be sure that matches up. fwiw, our home is 240v (the kiln's display indicates ~252v). Our run is very near fifty feet. The (e23T-3) kiln's plate indicates 48 amps. I'd considered going with the number four wire, but went with the #6 The cable we bought is rated higher ...75 amps. The vendor, WireandCableYourWay, had a good price** on #6-3C THHN-PVC TRAY CABLE WITH GROUND We also went with a fuse/disconnect box and replaced the supplied cord and plug with a waterproof conduit and #6 wires. *Not sure about the new models, just got several hits for J230 and 43.98 Amps Ah, GrayB uploaded an image. **The per foot price hasn't changed. With shipping, still less expensive than local vendors and better specs. I went with three conductor cable, for down the line someone might need (or want) 120v ...the third conductor is not being used in our setup. My understanding is the kiln (our kiln, the e23T) requires two conductors only, and the ground.

Hard to say without picturing it. Does it look like a lubrication point? Any luck identifying where the noises are coming from? Potential noisemakers: motor - bearings, brushes, both; wheel shaft bearings and/or bushings; belt, belt pullies; any of the moving parts rubbing on something.

Thank you C. Banks! ...I'm looking at the article on sustainability now, also interested in the Coppage, Faber, Schade, Yimnirun, Davey, and Randall articles, oh, and the "Why Science Communication Matters" one as well.

This topic resonates. Found this article (thanks to C. Banks for the link to the article list), "Actions for a sustainable future: Jürgen Rödel" here for transcript: Ceramic Tech Chat transcripts - The American Ceramic Society ...there's option to listen to the readings as well.

Bein' curious, and settled down for a late afternoon snooze*, taking a minute to look for that... ...found a scanned version of Hopper's book. The piece is "Trifoot Plate - Southwest Series." Searching that string, found on Hopper's blog the same/similar image, captioned thus: "RH - TRIFOOT PLATE - SOUTHWEST SERIES. THIS EXAMPLE SHOWS CONTROLLED LOCALIZED FUMING OF CHROMIUM RED GLAZE ON TOP OF TIN-OPACIFIED TERRA SIGILLATA" Here: PHOENIX: BRUSHSTUFF #1 (rhrising.blogspot.com) Sorry about the all caps, that's a direct copy/past (quotes added, of quote!). *Had appointment this a.m. (6:30 !!) with the specialist for a root canal. Yep, time for a nap!

Hi Vpwilkie, welcome to the Forum! The wheel is belt driven? ...where there are pulleys on the motor and wheel shafts, and a belt that connects them? If so, there would be bearings in the motor and also bearings for the wheel shaft. If the noise is definitely coming from the motor, it may be possible to replace the motor bearings...

Good question. A few patterns stand out: Where the largest mug in the display sells. I've bumped up my mug sizes several times now; what is now "medium" used to be rather large, heh. Some, no, many folks cruising the wares will go straight to seconds (minor cosmetic defects) and/or marked-downs, looking for a bargain. Much less often, a looker will beeline to the best piece in the display, and grasp it, then buy it. More mugs and bowls go than vases, teapots, and jars. What's happening seems to make a difference. When there are people picking up ware and not putting them down (! a buyer!!), others seem to follow along. Same for interested, happy, engaged, interested (yah, twice), inquisitive people. Somewhat same in reverse though. What people see, lots of variation there. Some see the prices. Some see the shape, others the color, or decoration, others watch the other shoppers most closely! Some are really looking closely at the potter. I like to see interested shoppers picking up and handling wares that interest them, for I (like to think I) make pots to be used.

Looks like the image Bill posted correlates "o'clock position" to degree angle. I'm not finding many graphics that depict correlation between degree angle and degree temperature. This one is a large cone 10 cone; the rate* is indicated (in °C) The temperature degrees per angle degree is greatest at the beginning of the fall/bend, least at the end. More fun here: Untitled (thermaltechnologies.com.au) How closely we have to hit the target for heat work for optimal results may certainly vary. In my (limited) experience, within a half cone to a full cone is plenty close enough for bisque, given that it's not a full cone on the cold side, for then I have to rush a bit to keep the glaze layer from being too thick. I don't mind having to slow down a bit for bisque that's not as absorbent... For glaze fire, some clays are much more sensitive to overfiring than others (per that same limited experience). *Temperature difference between clock/angle positions depends on the rate - how fast/slow the temperature is rising.

Do the holes go all the way to the clay? ...looks like they do (also not scientific!). If so, perhaps there are some larger "off gassing" particles in the new clay? They appear (also not scientific) to be random - all over the surface. If you're dipping, the glaze layer near the foot should be thinner. Are the problem forms thicker than your test tiles? If so, that could be another indication of problem particles, for the thinner wares "burn out" more and faster in the bisque. And so, if the new clay has more/bigger bits of stuff to burn out, a longer more thorough bisque fire - with plenty of oxygen - could help. See also drop & hold glaze fire: Drop-and-Soak Firing (digitalfire.com)

To drop and hold, the next segment has a lower target temp/target. Here the rate is maxed at 9999, and the hold is long, three hours (crystal formation), and the final segment is a controlled cool, falling two hundred degrees at the rate of 500°/hour, then holding there for a full hour. For a bisque hold (per prior post, to burn out stubborn organics in thick wares, and/or clays with lots of organic!), I don't believe it matters if the hold is on the way up or down. When running my manual kiln, I held at 1500°F on the way up and down! The new kiln, I set the 1500°F hold on the way down. See "Custom Ceramics Program" in the L&L notebook. Give a shout if any questions come up? There are regular members (and Mods) here that are very familiar with writing and editing custom programs. There are Horned Lizards in California! Grackle, the figures, how charming, and beautiful glazes, thanks for sharing!

All my flexible metal ribs are stainless steel, except for three, which are carbon steel (else a high enough stainless to rust*). Steel may be "blued" - it's pretty (subject to opinion, of course) and helps protect against rust and scratches. Bluing (steel) - Wikipedia ...blueing can wear away fairly easily, and additional measures against corrosion/rust may be necessary. If you like the rib, rinsing it clean, then drying it off and giving it a wipe with an oily cloth may not be too onerous? If you do keep an oily rag about, hang it up or put it in a fireproof container, for spontaneous combustion is a real thing, Spontaneous combustion - Wikipedia Just rinsing and drying may be sufficient, try and see. *Low series stainless steel contains more nickel and chrome. Higher series stainless steels may rust. added: metal ribs can become very sharpened through use! Does anyone else square off the honed edges with a file (or grinder, sandpaper, whetstone, etc.)?

Hi TahoeBlue, Welcome to the Forum! LaurenF hasn't been on the Forum since November last. You might try sending a message (which will be delivered via email); navigate to their profile page, select "message"... Looks like Lauren had found something - perhaps a sheet metal flange? - that bolts up, per the second image. ...12" fan, 13-1/2 in bolt circle diameter, search string suggestion, "12" round duct flange" ...maybe duct flanges | McMaster-Carr or 12" Flowtite Plain Duct Fitting at Menards® Gotta go to root canal appointment; I'd rather look up more flanges tho'!

We have/had several rolls of Con-Tact brand shelf/drawer liner left over from fourteen or more years ago. Lady is correct, the film is plastic-like; it can be wiped with a damp sponge. The other brand, I'll have to go look...

Hi Jem, Welcome to the Forum! While waiting on input from readers familiar with Fire Master kilns, please post a clear image of the information plate and the switch in question? The info plates typically have model and/or serial numbers, voltage, and amperage stamped on them.

I'd tried extended bisque fire hold (~1500°F) for red, dark brown and black clays I was trying out (a few years ago), where the idea was to thoroughly "burn out" the stuff that will burn out*. The hold did seem to help with the black clay, however, the main problem I was having with the red clay, fizzy bubbling, was most likely associated with too much heatwork. I'd set up a powered kiln vent at about the same time. Any road, my observation (notations were helpful here) was that random pits were greatly reduced in the white, buff, and other red** clays. My guess there is that random larger bits/chunks of stuff that otherwise wouldn't completely decompose (and hence, produce gas in the glaze fire) in a regular bisque fire get more, or even fully burned out with the hold. I've left the hold in ever since. I'm fairly sure I got the idea from reading GlazeNerd posts, thanks Nerd! *The black clay, in particular, could bloat where the clay was even a bit thicker. **I'm using a different vendor's red clay now, which isn't as sensitive to firing over cone five; it also throws better and is less prone to cracking during drying.

Drop and hold seems to be working/helping in glaze fires for me as well. I'm also holding in bisque fire, ~1500°F for an hour, powered kiln vent on throughout, which also seems to help. "Seems" on account of variables, aye. Some of the clays I've tried are a bit more sensitive to too much heatwork; some are very sensitive to too much heatwork.

Commercial glazes, err, some commercial glazes may contain less expensive ingredients and/or behave poorly. Less behaved glazes may: settle quickly, crawl, craze, pinhole ...have washed out color (especially where expensive colorants are involved) ... etc. When looking for recipes, starting out*, a few ideas (which I'd found here, in this Forum, and a few other places**) were helpful: from a reputable source; with helpful notes on application, durability, and heavy metal leach testing results; with pictures! I just picked several recipes, made a materials list, and went shopping***! From there, learned, err, learning from successes, failures/mistakes, and more reading. ...and thanks to several Forum regulars for insight and assistance. *Coming up on six years ago, how time flies **Digitalfire.com, a trove of information; the glaze recipe book at local JC ceramic lab (we were using the glazes - direct experience!); Petersen's book The Craft and Art of Clay; Van Gilder's book Wheel-Thrown Pottery; and several other books, magazines, and web pages. Oh, web pages! ...Hesselberth's website can still be found, FrogPondPottery, Tested Glazes | Frog Pond Pottery (archive.org) Lakeside Pottery also has glazes sub-pages with pictures and notes... ***took the pickup truck, packed the load up against the front of the bed and tied it down tight, some twelve hundred pounds of clays and glaze materials...

I'm using petalite in my liner glaze*, which was a study in craze control. Spodumene has more lithium per unit weight, but petalite was more competitive in lithium per unit co$t, with side benefit of avoiding the reported foaming/rinsing. *was, on account of petalite costs have gone up so much! I'll be re-visiting my liner glaze formula soon, very ...I have enough petalite to last a year or two.

"...do you staple/glue/tape the paper to the board? Does it last very long?" I'm folding the shelf paper over the edges and stapling to hold the edges down. The shelf paper has a removable backing that reveals a sticky side; the side that shows is shiny. I needed ware board - smooth, for freshly trimmed feet! I'm not doing any work on the shelf paper surface, just setting down and picking up pots; they don't show any wear yet, but it hasn't been terribly long either.