Hulk
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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 workYour 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. -
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... -
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 CThe 11 (plastic body) is 2.8% at 1200 C, .6% at 1300 C
In that case, firing to ~1260 C may be about right.
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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?
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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! -
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.
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Ah!
Thanks Johnny, thanks HB!
How's it look now?
The Activity Stream has been replaced by a Topics widget/thingy. -
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? -
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!
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Any chance there was something on the underglaze that caused the clear glaze to crawl (e.g. fingerprints) and/or the underglaze burnished by contact with something?
If you are dipping the mugs into clear glaze, the rim area could get a thicker layer of glaze.I'm typically going for a thicker layer of liner glaze at the rim, for that's the portion that thins the most during firing.
I'll pour in, pour out, wait a bit, then dip just the rim for more thickness. -
Shimpo wiring diagram indicates shr623-2
...ah! Same one Peter found (above).
I'm finding that part discontinued (see also TANAC006232).
Perhaps figuring out what a switch actually does so a suitable replacement can be found is the only option. -
Just curious, how were the the coats of underglaze and glaze applied?
Looks like the clear glaze beaded up in the portion between noon and 2:30 o'clock in the image.
Was the glaze good around the rest of the rim? -
Stainless steel, if available, should last longer, still, use thread compound against corrosion/siezing, e.g.
I went with wingnuts and lockwashers.
Overlong bat pins can be a hazard, measure carefully!- Bill Kielb and Pyewackette
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Hi Dz,
Welcome to the forum!
If you're able to remove the switch, taking it to your local hardware shop to match up a replacement might be an option?I'm seeing Krueger carries a replacement, does the image match?
Shimpo RK-2 Parts – FWD/REV Switch Knob (RK Common) – Krueger Pottery SupplyPerhaps someone familiar with classic RK2 wheels will chime in here...
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That a significant portion of thrown pots don't come off the wheel close to exactly round, never mind stay that way seems true, has been noted ...and yet, many do!
I had a bowl with a wonk in it, so picked out a finished bowl (a round one!) - a bit bigger and wider, so easy to hold on to and makes contact at the inside rim only - to use as a rounder. Now I have several shapes set aside to round with.For cylinders, am still using tapered containers...
...I like the faceted tumblers, they do the job, less prone to sticking.
These type of rounders are set in the rounder place, on account of they have a hole in the bottom; if/when a seal is achieved, the hole is helpful.
looks like dormant threads are archived after two years of inactivity
This thread last updated two years ago tomorrow*
if update.date +2 years < today's date then
archive -
Hi Tony,
Welcome to the Forum!
Good question.
Depends on what you're making and how you go about it - you might start with a cut off wire, a set of sculpting/modelling tools, and perhaps a paddle, a set of rails and a roller.You'll need a surface to work on and somewhere to put your in-progress work.
When you take a break, keeping the work from drying out may be important, so a spray bottle and coverings*.
Buckets are key to my process, water to work and clean up with, clear water for final hand rinse afore leaving the work area, another bucket for clay scraps that I'll let dry out for reclaim, yet another bucket for clay slop/slip - buckets!
Big sponges for clean up, small sponges for working with clay.*cloths, plastic sheeting - something to slow down the drying.
I use rigid containers, inverted over each piece, which isn't a particularly popular approach - it works for me! -
Hi Zoe,
Welcome to the Forum!
The 254 and 240 both look to be vitrified at 1240C, cone 7; are you glaze firing to cone 7?
0254: Pottery Passion by GOERG & SCHNEIDER
0240: Pottery Passion by GOERG & SCHNEIDERAre you using commercially prepared glazes, or mixing your own?
If mixing, please post the recipe.Sorry I don't have any specific glaze suggestions.
The low COE liner glaze I was working on fits some light stonewares I found; let me know if you'd like the recipe.Perhaps another Forum member will have specific suggestions.
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Good question!
Would it not take some time to:
test materials - find a casting slip that behaves well and a range of glazes that also behave and fit well;
create/obtain a range of molds;
get the casting process down;
get the firing process down?Is there special equipment - slip tank, mixing tools, the rack where molds are drained, mold storage?
Plaster, plaster mixing tools, special mold making gear?If you're making molds, that's another level of complexity?
Would a unit on casting in your first and second term ceramics courses lead to a full term in casting?
That would give you another several months to iron out the kinks, and meanwhile, break in those new kilns. :|Perhaps there's an existing program to tap for info...
...try searching "ceramic molding in high school"
What comes up near the top of the page, looks like skeleton of a lesson plan (not a full term), right above your post!
Ideally, there's resources - people and print - that can help.
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There's a nice write up on page fourteen of this month's (March 2023) Ceramics Monthly magazine.
If ever I transition away from tape for a clean line at the foot, magnets it will be!
I've tried waxing, wasn't getting the sharp line, where there's full thickness up to the edge that tape can give, and there's the grip problem.
The magnets would solve the grip problem!My grip isn't reliable enough on a narrow footring.
I want to be able to give the ware just the right amount of shake at the right time, in the right direction(s), so grip is important.
Also, keeping the ware flat throughout the dip is important - to avoid the burps - having a good grip helps a lot.
Min's magnet on a wand/handle should make keeping the ware flat much easier, as deviation from flat is amplified by the length of the wand.- Bill Kielb and Rae Reich
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Lots of practice, that appears key, as Florian Gadsby demonstrates in his video clip on the subject*.
He's tapping on the away side, but between three and four thirty or so?Looks like John Hasegawa is tapping on the toward side, but at less than nine o'clock, the pot is moving away from his fingertips.
Both nod to the many varied approaches, which I appreciate!
Left hand seems natural to me (I work clockwise). I haven't progressed much with tap centering, although Florian's video has inspired me to practice more.
I might yet find a way to be consistent, however, it's been like throwing a baseball is for me (now), I can do it, but every once in a while - too often - a ball goes sailing off in a wholly unintended direction, which I attribute to nerve damage. So, I can throw underhand consistently, and left-handed consistently, if not very well.
I can tap a few times effectively, then oops. The oops taps occur too often, oh well.I hadn't seen any of Hasegawa's clips, thanks for the intro!
*Florian Gadsby
How to Tap Centre Pots on the Potter's Wheel - YouTube -
Looks like one can get closer to the wheel head (compact, as Mark points out)?
The height may be different.Have you ever driven a Skutt?
I like mine, but I wouldn't say it is better to work on than a strong Brent.
I've the built in cast pan, which I really like for setting my forearms on...That you like it is the main/good thing!
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Any chance vertical storage would work?
If not glazed cylinders left over, perhaps some other cylinder, e.g. half gallon black plastic planter (drains well), plastic tumbler, five quart snap lid (Home Depot) container...I keep my throwing and trimming tools in separate cylinders, then switch them out from the wheel's basin when changing task.
The tools that I don't use very often are in drawers.The points and edges may dull when stored with the sharp bits down, however, the sharp bits facing up is when, not if, someone gets hurt.
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Feel for the clay, precise economy of movement, as they improve with effective practice, so will the clock.
When looking for a clockwise direction video clip that I liked, watched some of the clips I used to watch over and over, like these:
Clinton Pottery didn't post many video clips (maybe two?), lot to see here
Mug throwing, advanced production techniques, Clinton Pottery - YouTube
I like his book as well
Michael Casson - The Craft of the Potter - Throwing (extract) - YouTubeWhen some time has passed, I'm still seeing others' throwing differently; the clips are still the same, but I am not.
What Clinton Pottery says about clay conditioning - I believe, more and more as time goes by, it being my experience - I'd forgotten, that video clip is where I first heard what a difference the uniformity/homogeneity of the clay makes.
gt400 not reversible?
in Equipment Use and Repair
Posted
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)
