[Inflation is hitting hard now]

I've just over sixty pounds of Gerstley Borate to work with whilst figuring out replacement(s)...

[QotW: When doing complex pieces do you mix and match, or do you design and one off?]

Where there's more than one part, I still almost always make extra parts*.

Handles, I'll typically pull an extra one or two, then recycle the extras.
There isn't always a "worst" one, nor always an oops, but when there is, the extras come in handy.

Lids, I'll make several extra, then check for fit, profile, feel, etc. after bisque and match them up - a matching mark in underglaze helps me keep them together.
The extras pile up, but so handy for oops, broken; yes, we might have a lid that fits that; I don't like any of these, maybe there's a fit in the boneyaaaard; etc.
When the lid and piece are formed similarly - same thicknesses, similar arc/profile, similar amount of "working" - they have a good chance of fitting together.
A good chance, heh.

Put togethers - like teapots, also towers, extended vases and pitchers, fountains - I'll make more add on bits than bodies, then pick at assemble time, and recycle the extras.

Early on, I'd seen Bill van Gilder's video clip on lids, where he advocates standard sizes.
I started out on the half inch, then switched to millimeters; I do 80mm for cups, jars, teapots; 100mm for larger mugs and jars; 120mm for jars; 140 and 180mm for jars and bowls.
Standard sizing helps!

*Here's some extra lids

I'm throwing the knobs, then torch them to leather hard just afore needling them off to attach.
Having tried a few (not all) lid styles, I'm doing almost all lids this way now - no gallery required, fully glazed container, lid and piece fired separately (not touching).
The lid is thrown upside down, trimmed upright. The cylinder knob provides width and height with uniform thickness - without bulk.
The underside of the lids gets liner glaze.

[QotW:How many pieces do you work on at a time during your normal workflow?]

For firing and glazing, driven by what fits in the kiln, which, happy accident, I had just enough counterspace for a kiln load with leaving room for a glaze bucket, some tools, a cleanup water bucket and sponge, and splash room*.

In making, from one up to forty or so. When in a flow, there's just thrown, ready or almost ready to trim, and another batch in between.

The weather makes a difference in how fast things move along.
Controlling and/or suspending drying is key, as Shawnhar points out.

*The new Studio space will have to have the same or more counterspace!
...while seven cubic feet of kiln space seemed much too big, starting out, I'm used to it now, so looking forward to getting back to it.

[Hi! Kiln parts/wiring questions]

Hi JLay,

I'm seeing an earlier request for the same info got no replies, however, in this thread a Forum member posted a diagram they had authored, same/similar kiln, about halfway down the first page

Kiln taking longer and longer to fire - Equipment Use and Repair - Ceramic Arts Daily Community

Perhaps that will help?

[Buying a pottery wheel]

There are a few threads here on that/similar topic - shopping for a wheel, that's how I found this Forum!

Pottery Wheel Advice/suggestion - Equipment Use and Repair - Ceramic Arts Daily Community
Best Pottery Wheel for Beginners? - Studio Operations and Making Work - Ceramic Arts Daily Community
https://community.ceramicartsdaily.org/topic/26802-any-tips-on-purchasing-a-wheel

...there's more; try some different search strings, particularly the brand/model you may be considering.

If you can, take some wheels for test drives.

[Imery's Kaopearl kaolin casting slip]

Antiprex, a dispersant, rheology modifier, per worldofchemicals.com

Antiprex 461 is an aqueous solution of low molecular weight polyacrylic acid. It is an effective dispersant and rheology modifier for kaolin, gold processing slurries and other mineral suspensions. It functions as an efficient antiscalant for the prevention of scale deposits including calcium carbonate, calcium sulphate, strontium sulphate and barium sulphate in industrial systems.

Alcospere, a dispersant, per manufacturer's website

Alcosperse® 149 is a pale amber liquid acrylate-based dispersant designed for general use in kaolin, calcium carbonate, paints, paper coatings and a variety of pigment slurry applications.

Just curious.

Hi Alistair,

Welcome to the Forum.
What are the units for those two ingredients?

 

[Replacement Elements for Skutt KM 1227]

"...should be simple enough to trim the shelves using a wet saw (tile saw)."

Just saying, on account of I've trimmed concrete pavers, 1'x1'x2" and the 1'x2'x2", did a tile countertop in 3'x3' porcelain, and three showers, all used some 1'x1' and 1'x2'; all cases I'd prefer the wet saw, although I'll admit the three foot tiles were a bear on account of the weight.

[Replacement Elements for Skutt KM 1227]

I had an old KM1027 (1988), 2.5" brick; we didn't bring it with us on our move North, however, the shelf set is only about five years old, so kept that.

Haven't decided on a new kiln just yet.
Most all are 3" brick now.
To use my shelves (without cutting*) in a ~seven cubic foot kiln, looks like the choices are Skutt (there are 2.5" brick 1027 models out there), Bailey/ConeArt - looks like all the other choices are a bit smaller inside diameter.

*should be simple enough to trim the shelves using a wet saw (tile saw).

[Info on an older Skutt kiln model]

Some info here:
Sandstone Manufacturing? - Equipment Use and Repair - Ceramic Arts Daily Community

Pottery Supply House still has this page up (Firecraft Kilns were made by Sandstone Manufacturing, it seems).
Firecraft Kilns – The Pottery Supply House (psh.ca)

You might try calling Skutt; they are typically very responsive.

The condition of the kiln - bricks, elements, wiring, etc. - that's important.
The temperature rating - what max temp can the kiln reliably and repeatedly achieve - that's important too.

PHS and/or Skutt may be able to help with the second point.
Another resource, try Euclid's Elements.
They are in Canada and sell elements for all manner of electric kilns; they may be able to help.

[Spodumene Substitute Analysis]

I'd noted Spodumene, Petalite and Lithium Carbonate pricing 1-DEC-22

At that time, northern California supplier (that I frequent) had a better price than other vendors I've used.

Same NorCal vendor, since then, Petalite has gone up 25%, Spodumene (substitute) is up a bit over one third!
The spod is well over twice the cost per pound, but it doesn't have 2x the lithium.
Their spodumene sub is 6.8% lithium.

I'd already (somewhat arbitrarily) chosen petalite for a lithium source; the recipe in question has just a trace of lithium, so I believe petalite is appropriate...
The lithium unity, percent by weight, and mole percent are 0.133, .88%, and 1.86%, respectively.

Any road, if the percent lithium changed, for sure I'd revisit the formula/recipe, for lithium is powerful stuff!

[What plug/receptacle to use for older 50amp kiln]

Hi Estrata,

Welcome to the forum!

Likely the kiln tech experts will want to know specifics; does the kiln have a plate attached indicating the amps, phase, voltage, model number?

[Lincoln 60 - heads up / issues?]

There's a clay company in Lincoln (California) ...aha!

 

One goes right by the piles of clay, large building, stacks of clay pipe, etc. when passing through town.

I'm not seeing where Gladding, McBean are in transition/difficulty, also not finding any reports about the clay changing.
Another local (Northern CA) clay producer has a history of noting changes as the mine(s) deepen(s); I buy clay from them, IMCO.

There are somewhat recent shows about Lincoln clay, PBS "Rob on the Road" (season 7, episode 2; Rob Stewart), "California's Gold with Huell Howser" (episode title "Terra Cotta"), John "Bartell's Backroads" (ABC 10 KXTV)...

[Was it a mistake to pass on an old kiln?]

No amount of lead is safe, so says the WHO, CDC, State agencies, etc.

[Spray Booth Setup: Ventilation Fan]

Many of the images I'm finding indicate the fan is designed to blow (hence turn) in one direction.
The fan label has a flow direction arrow.

Lauren captured the three phase reversing instructions in the third image (the single phase instructions, however, are truncated).
I'm not finding a matching doc; the one I did find addresses rotation direction thus:

[gt400 not reversible?]

Hi Merav,
Welcome to the Forum!

The current model features "... Convenient, 3-position, reversing switch comes standard..."
The switch on your wheel has two positions only?

I haven't found any documentation on the GT400 model without said three position switch; looks like it's been standard for a very long time.
That model wheel has been around for many decades though...
Does the cable from the control box to the motor have a reversable plug? One of the images I'd found indicates there's a plug, but I can't tell if it is easily reversible.

Laguna is typically very responsive, try calling (have model and serial numbers ready)

[Spray Booth Setup: Ventilation Fan]

"...fresh air into the  house somewhere. A lot of it!"

Indeed; what provision for makeup air?

[Kiln creating bubbles in clay]

Hi SaeChoi,

Welcome to the Forum!

Two suggestions:
i) if you can get samples from the Studio, fire side by side, just to confirm the clays are the same
ii) place a cone pack on each level, to confirm the heat work

Your new kiln may be running hot?

A small kiln will likely cool much faster.
You might program a slow cool to emulate the slower cooldown of a larger kiln.

I tried a bag of Laguna's Speckled Buff clay last year.
It was labelled Cone 5.
I hadn't tried firing it hotter than Cone 5; the pieces on the shelf that was closer to Cone 5.5 were a bit more toasted looking.
I really liked the clay and will definitely buy more! It was easy to work, takes my glazes well, and there were less defects.

Some clays tolerate overfiring better than others.
Some of the red, black and dark brown clays I've tried misbehaved (bubbling, bumps, fizzing) when overfired.

[QotW: What tools that are not specifically for ceramics would you recommend a potter have in their shop?]

Well fitted dust mask (P100 by 3M in size medium), kiln glasses*, safety glasses.

OptiVisor (magnification), adjustable/desk lamps, spot lamps, and area lighting.

New studio will have a heat pump! !!
The weather here is significantly hotter and colder than where we were afore.

Insulation against cold floor/slab and alloy castings (foot control) - rubber mats, bubble wrap.

Shelving, pegboard, countertop/work surfaces...

Drill bits (twist), calipers (cheap plastic ones), ball point pens, many buckets (2.5 quart, 1 gallon, 2 gallon, 5 gallon), large sponges (big!), notebooks.
Home made trimming tools (from hacksaw blades), repurposed items as ribs, stick tools, pointer tools...

"Ditto" everything already mentioned, with extra nods to music/sound, mop bucket, dremel, diamond dust discs, clean rags/cloths, closed container for dirty cloths (anything with even the Smallest Amount of dried clay on't, in there, else wetted).

*protection against harmful rays when looking into the kiln via peeps, and, And, protection against any superheated flying bits.
Welding glasses of proper darkness/tint, with side shields, that's what I'm using, hence, not strictly a pottery tool...

[White raised bumps after glaze firing]

Hi K,

Welcome to the Forum!

Edit/Add: the spots are not craters, they are bumps/lumps!
Scroll down to agglomeration...

Are the white spots "craters" - where the center of the spot is bare clay?
If so, could be that there are particles in the clay that are off-gassing.

Helpful in clearing up fine bubbles (fizzing), cratering, and pinholes:
  Adjusting peak glaze fire temp
  Drop and hold after peak
  Bisque fire adjustments (hotter, longer, with oxygen)

1260 C may be a bit too hot*?
Some clays are sensitive to over firing, others are more forgiving.
If the clay will fully vitrify at a lower temperature, that may help.

A smaller drop, ~55C, then a longer hold - try 30 minutes - may allow the glaze to "heal over" the craters.

Bisque fire with oxygen, extended hold at 815 C may also help, especially if the defects are more prevalent where the clay is thicker.

I'm not finding shrinkage and absorption details on that clay body.
The linked page indicates max 1300 C - not sure what "max" means in that context - could be the point where the clay begins to slump?
The hottest sample is labelled 1240 C (1260 C is much hotter than that!)
Technical data sheet here: Ready-made plastic bodies - Arno Witgert seit 1820 (witgert-tonbergbau.de)

Any road, consider placing cone packs on each shelf (a half a cone hotter/cooler can make a big difference), keep detailed notes.
Please do post updates!

*Looking at the "Water Absorption %" numbers, the 2040A clay, for example, is is 11.1% at 1100 C, 1.5% at 1200 C, 1.4% at 1300 C
In that case, likely not worthwhile to fire over 1200 C

The 11 (plastic body) is 2.8% at 1200 C, .6% at 1300 C
In that case, firing to ~1260 C may be about right.
 

[Forums page layout]

I'm seeing two columns on the Forum/Browse page, where the first column is the subforums, the second column has the Topics and Recent Updates.

That wide subforum column lists each subforum where the entries include the name, a description, the Moderator, post count, and a link to the most recently updated thread.
Is it the links (red arrow) that you are referring to Lee?

 

[I purchased a used sitter kiln model-k 10]

Hi Meral!

Welcome to the Forum!

If the kiln has a medallion/sticker/nameplate indicating the model, volts, and amperage, please post a closeup image.

= via Google Translate English->Turkish

Merhaba Meral!

Foruma hoş geldiniz!

Fırında modeli, voltu ve amperajı gösteren bir madalyon/etiket/isim levhası varsa, lütfen yakından bir resim gö

Particularly important:
volts
amps or amperage
phase

***

Meral's post, as translated by Google Translate:

Hello,!
I am a ceramic artist and bought a used kiln.
I just came to the US from the EU. I will use it in my garage.
The oven is a bit old. Its name is Sitter Kiln Model-k 10.
Have you used it before?
I am looking for a plug, do I need to install a plug system or can I use a changer?
I'm a little confused. I haven't tried either. I need to try to see if this works.
Do you have such a plug?
If you can help me, I will be very happy.
Thanks!

[Lockerbie Willie Wheel information]

How much does the surface of the wheel (at the outer edge) run out?
IOW, how much vertical movement is there?

If the wobble is horizontal only, that shouldn't shake up the work, excepting for the visual - a large diameter bat can help there!

If there is a significant up and down wobble, I've found that hard to work with.

[Forums page layout]

Ah!

Thanks Johnny, thanks HB!

How's it look now?
The Activity Stream has been replaced by a Topics widget/thingy.

[Forums page layout]

Hi All,

Regarding the Recent Posts layout change concern.

I'm curious, how does the Forums/Browse page look for others?

I'm seeing the right hand column about split, where the top half is Recent Posts and the bottom half is Status Updates.

Here's a screenshot (where I'm logged in under an account I registered for testing).
Right now, there's five Recent Posts.
I've cropped the bottom half of the page; there's another four or five Status Update entries down there.

 

Is this what other Forum members are seeing?

I hadn't noticed any changes.
How is it different than before?

[G200 vs G200HP]

Good question!
Confusing, looks like G200 ran out, replaced by G200HP, which also ran out.

If possible, compare the G200HP component analysis against the material you have now.

There's enough potassium and sodium differences between the G200HP and "Old Blend" to justify small batch testing*, imo.

Digitalfire article:
G200 HP Feldspar (digitalfire.com)

This thread has some history:
Feldspar G-200 - Clay and Glaze Chemistry - Ceramic Arts Daily Community
 

*else limited testing, then look to adjust small amounts if you already made a big batch!