Hulk

I just had a minor flood last week in my garage, ( blocked drain) and my Brent wheel would not stop.  I took the bottom plate off the pedal and saw some moisture.  I blew it dry and tried to adjust it and it wouldn't stop spinning.  Spent hours on line searching for answers, saw high prices. My wheel is a Brent CK (a kit I think) and is at least 50 years old although not used for 3 decades so I was getting resigned to spending $600 to fix it.  I tried adjusting the pedal one more time and it works now. Phew.  It is a great wheel.

Just when I think I have seen it all; most of it anyway. I fired the above shown sample to cone 04, and was surprised when I opened the kiln. The new sample is on the left, and a standard terra cotta on the right. From the deep color (reddish/orange), possibility that this sample might have limonite in it. Limonite ( natural yellow ochre), which would account for the deep color hue. Wild clay can get wild, even for those that are familiar with it. This sample will certainly go to the lab for analysis. Not cracked it open yet to check for black coring, but I suspect there is. I dipped both in water for a quick absorption test. The terra cotta drank it up, and the limonite? sample did not. 
Tom

Testing/proofing on test tiles, small slabs, et cetera, time permitting ...afore committing a large piece.
How many words are you looking to depict? A phrase, a stanza, the entire lyric?

As for decoration, have you ever thrown a cylinder, then decorated it by either stamping, or incising then shaping the cylinder into the shape you want?  I find this a very satisfying way to work, and if you have letter stamps, or a decent script hand you can work wonders with phrases in the clay. Then after bisquefire before glazing you can use a stain/underglaze to work color into the script and wash off the high areas. This will allow the decoration to show up under glaze layers if the glaze layers are thin enough and not too dark in color. Check out some of the posts on my blog site. . . listed in my profile.
 
best,
Pres

Article from yesterday's NYTimes:
Doyle Layne’s Dazzling ‘Weed Pots’ at Kordansky Gallery - The New York Times (nytimes.com)
I'm curious why the Times hasn't enabled commenting on this article?
There's an article in one of year afore last's Ceramic Monthly mags (JAN-21):
Doyle Lane: Weed Pots (ceramicartsnetwork.org)
The Times ran a different article a few years ago...
Adding a New Name to the Canon in Clay: Doyle Lane - The New York Times (nytimes.com)
This one has comments, which can be interesting...

Mr. Hansen's articles on crazing, crazy helpful!
  In short, that crazing a) is a defect, b) has clear cause(s), and c) can (and should) be corrected isn't universally known.
His takes on liner glaze also stands against the tide - tide of brightly colored liner glazes, "functional" ware.
Liner glazes (digitalfire.com)

Hi Min, gosh - complexity bias! I didn’t know this was a ‘thing’. Describes me to a T! 
To demonstrate this, I actually had about seven different clays in the firing together with a whole bunch of new glazes I’d made (as I said, I’ve never made a glaze before, or indeed done a glaze firing in a kiln!) - surprisingly, in fact amazingly, I have got some really nice results - lots to work with going forward, and I think one of the lessons I’m taking away is that I need to simplify things for a while til I gain more confidence
 

This has been a learning experience.  I've posted fresh ideas, new readers start there.

PS Some of my previous posted ideas  left here for completeness.
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A quick google failed to find a public domain manual. Although there was a site offering/purporting to have it, I'm always a bit suspicious of those.
I assume that you've checked the fuse in the plug. It looks like it might have what we call an ELT (earth leakage trip) in the UK.
from https://tinyurl.com/39sknyej

Have you tried pressing what looks like a rectangular button on at the top RHS of the blue plate (while the power is off) it might reset the ELT.

PS The "Leakage Protection Device" arrow seems to be pointing to a lamp, rather than the second button ELTs usually have.  Can you confirm?
... found a better image (possibly from a different wheel)
from https://m.media-amazon.com/images/I/81Hi6FfkgqL._AC_SL1500_.jpg

Which looks like the rectangular button is a "test" button (trips the device). So how do you reset, is it just switching it on (which you are already doing)?
So maybe I'm just saying make sure you switch it off then on again while the power is connected -and report what the lights do.
PPS If you want to risk it (they might be clickbait)
https://lb.manuals.plus/vevor/gcjx-series-pottery-wheel-machine-manual#axzz88NpegZVN
https://device.report/manual/5720904
... the second has some general advise on the page

Bingo! This product totally worked for me (pushing it into seams from the outside). Easy breezy. Already had it lying around, so thought I'd give it a try. Sticks well enough to the plaster, but easily peels off after casting, to be used again:
Sargent Art Plastilina Modeling Clay, Non-Hardening
(unable to turn off bold feature above after cutting and pasting product name - not really shouting) 

1. Water hull and stretched membrane were both theorems introduced by F.H. Norton, Phd. The water hull in simple terms meaning a single molecule of water is nearly equal to sub-micron clay particles, and a single calcium particle. Without paragraphs of science; the theorem states that sub-micron clay particles, and calcium particles are more effective at creating plasticity because they are of equal size. Sodium and magnesium are much larger; and the water molecule has to “stretch” ( stretched membrane) to encapsulate either. That gelantious effect created when you put bentonite in clay or glaze is in part a result of “stretching” the water hull. To further illustrate is Darvan. Powerful suspension agent, but few know that Darvan works in part by neutralizing sodium and magnesium ions. This allows remaining calcium to work more potently, in addition to the strong negative ionic charge created by high alkalinity. In discussing wollanite: then you get into alternate silica structures. Polymorphs I believe is the correct term. Pure silica has a high COE 12-14, while melted silica has a low COE 4.50 or so. So silica that has undergone thermal changes due to volcanic, or heat/pressure form a different crystalline lattice- thereby lowering it natural COE. For that reason, wollastonite reduces shrinkage, and adds to plasticity due to the calcium content.  Personally, I add 2% whiting. 
2. Plasticity develops over a 5-7day period unless it is ran through a de-airing pugger. Plasticity levels climb over the next several weeks. Plasticity is never an immediate reaction. A big mistake potters make is increasing ball clay/plasticizers until it is plastic upon mixing. However, in 5-7 days they have a bag of silly putty. Your projected plasticity in a week or so govens ball clay additions; not what it feels like when you mix it. Also note that not all ball clays impart the same level of plasticity.  Kentucky 5 for example is on the lower end of plasticity; yet it is still deemed plastic. OM4 is a medium plasticity ball clay, and FHC (Foundry Hills Creme) is high plastic. You have to calculate those levels when adapting a clay recipe. A common clay recipe might call for 25% OM4, and if you replace it with 25% FHC: you will have silly putty. If it calls for 25% OM4, and you replace it with 25% Kentucky 5; it will mature to the short side of plasticity.  Ball clay specs will often give CEC (cation exchange values. OM4 has a CEC around 5.8 (last I looked), and FHC is above 9. (from memory). The higher the CEC climbs, the more plastic it is. A recipe calling for 25% OM4, can be replaced with 15% FHC to achieve the same plasticity level.  Formulation rule #2; the higher the plasticity, the more water the clay will absorb. That is also translated; the higher the CEC value, the more water it will absorb. You do not want a tile body to absorb or hold any more water than necessary to form: because excess water = higher shrinkage. Throwing bodies need enough water absorption to make it malleable, but absorbing higher amounts of water will cause it to slump or fold on the wheel. The exception is hand forming, moreso pieces that require several days, or multiple steps to create. In this case, the additional water absorption will delay drying, and make the clay more suitable for carving or detailing. 
3. In your earlier post, you listed the mineral composition of the clays you like. Did you notice the alumina hovering around 25%?  24-30% is common for ball clay and fire clays, although fire clays often drop below that. Kaolin typically runs around 37%. If you formulate using clay(s) with lower alumina and higher silica; then you will have higher SiAL ratios; 5:1 is normal for stoneware. Porcelain uses kaolin, which is higher in alumina, and lower in silica: so the SiAL for porcelain bodies hover around 4:1.  The additional formulation criteria also comes from these natural SiAl levels. Stoneware bodies naturally have lower alumina and higher silica: so the silica addtions are limited to 10% for that reason. Porcelain bodies (kaolin) have higher alumina and lower silica: so silica addtions run 20-25% for that same reason. 
Bonus note: Porcelian relies heavily upon glass/mullite development to create nearly zero absorption. This is the primary reason flux additions run in the 25-30% range. Stoneware bodies focus on PSD (particle size distribution) to keep absorption under 3% (functional ware).Stoneware recipes can have up to 5 different individual clays; which plays a role in particle distribution, but also in working properties, and final fired color. Stoneware being more dependent upon PSD, also means flux additions ae kept to 10-15% total. Flux in stoneware does develop some glass, and does lower absorption some. However, flux addtions serve  a more central target of preventing cristobalite formation.
Tom

I’m thinking about adding some safety to my kiln, finally. Too many hours spent fretting I’m going to make a spectacle of myself. So I’ve been wading into the world of baso valves and see it’s a little more complex than I thought. The question I think I need to answer is whether I need high pressure safety valves.
The baso valves from big clay retailers are the H15DA, rated to 0.5 psi. Ward Burner sells that one as well as a high pressure one, the H19RA rated to 25 psi.
Now, the nitty gritty. My kiln is about 12 cu.ft. powered by two MR100 burners, propane. I have a variable regulator at the tank and that’s what I use to adjust the burners. By the time I reach temperature it’s sitting around 3.5 psi. Seems I need the high pressure baso, but wanted to ask here in case I’m understanding things wrong. I also see a note on Ward Burner site saying the pilot light for high pressure valves needs to be regulated as well, so…another regulator. Two.
Any feedback is welcome. 

Yes sir, thanks. Always got em disconnected, I don't do electricity very well, lol.

Kelly: 
I will assume your 03/04 cone range equates to 1950-2000F range I have seen wild clay samples turn to a puddled blob at cone 06. From what you report; alumina is in the 14-15% range. Yet, I also suspect you have a fair distribution of ultra fine particles. The U of I (Champaign/Urbana) did some extensive studies on particle size = melt temp many decades ago. Although the lack of alumina is the primary cause of pyroplastic deformation, particle size can add to that issue. I would run a line batch: 10%, 20% ad 30% kaolin additions. Almost all kaolin has 37% alumina, and ball clays run 24-30%. I make test cones which mimic typical Orton cones. I just make a 2” square, and carve a cone when it gets leather hard. I do not get overly particular about it: just some resemblance to a cone. The angle, and the narrowing tip is the most important. Can put it anywhere in the kiln on a waster slab. I do find it interesting that your clay is so reactive in just a single cone variance. I do not get overly involved with processing new samples. Get the obvious sticks and pebbles out of it, make a cone; fire it up. I want to know the properties before I begin processing. Like the post above, I will just place one of the small slabs/pieces in the kiln and fire it. The one thing about wild clay: you have to have a starting point that gives you some basis/direction to steer the processing.
Tom

Hey Everyone! I want to thank you all for your advice! My maker space will try a lot of these out to see which will work best for us. I'll be sure to keep this thread updated with our progress. @Piedmont Pottery I'm also curious if you find that adding the epson salt affects how the reclaim pottery throws afterwards in addition to firing and glazing. 

Hi Rebekah,
Good question!
There may have been some movement as a result of recent Forum software upgrades?
Any road, look at the top right for the letter icon, between the Bell (Notifications) and your avatar.
From there, select the "Go to Inbox" to see a full inbox pane with tools, etc.

Give a shout if you've any trouble!
Note, the Triangle icon (reported content) may only be visible to Moderators.
...confirmed, the Triangle icon is not visible in normal accounts.
 

Mr. Hansen's articles on crazing, crazy helpful!
  In short, that crazing a) is a defect, b) has clear cause(s), and c) can (and should) be corrected isn't universally known.
His takes on liner glaze also stands against the tide - tide of brightly colored liner glazes, "functional" ware.
Liner glazes (digitalfire.com)

I have after a lifetime of art show/fairs retired from them except my one local show which I am a board member on and this fall will be its and my 49th annual North Counrty Fair. in September.I still have a few shows that want me but I turned them down at this point in life. its been 50 years now of selling pots.
Other than that show I still have my local outlets which still sell an amazing amount of work. Two are wholesale (orgainic food markets)  all within 15 minutes of home. My work is on a high traffic end cap in each. They order via email when needed about every 4-6 weeks. Orders are usually average $800 or more
I still sell to a few gallery /gift shops wholesale as well and I still have after many decades a few consignment shops that send checks monthly . These are many decades old and well trusted. These are a 50/50 shop and a 40/60 shop
I also have a large pottery gallery that  only  sells pottery that is 10 hours away that buys an huge amount of wholesale twice a year.He is my best costomer and best business person I have ever dealt with.I drop that order off at his brothers about 4.5 hours away.
I have a 100$ minimum on my web site to slow mail order down (which worked well during covid buying craze) . I still ship a fair amount of pots to customers all over the USA via Pirate ship UPS via my web site. One customer I just finished making for ordered 41 mugs (well over 1k order) so when I'm dead and gone he still could have a morning coffee from his favorite my mug as his teens break about 3-4 a year. This order he will pick up later in summer in SFO area from my partner when she visits her brother in SFO area. That way the packing is loose and easy like a fair packup.
So far in life the new Etsy and other sites have not even been a thought for me which is great as I can focus on sellin g larger amounts at a time.
I would develop your local sales over any internet sales site first as these tend to last a lifetime or at least for me they have. If you live in the middle of nowhere than the net is your only option unless you travel with the work. Art fair shows are good if you like people and are good with them.-Not for everyone. In 50 years of shows I have a few stories to tell for sure.

I think that Tony Hansen's demonstration of the fallibility of ChatGPT is worth posting.
ChatGPT is completely wrong about the cause of glaze crazing!
https://digitalfire.com/picture/3159
... a fine example of ignoring the elephant in the room.
... a fine example of ignoring the elephant in the room by ChatGPT
PS It reminded me of a very old software engineering joke (1970s?).
A man was been taken on a cross-country flight in a helicopter. During the flight the ground became completely covered in dense fog, and the pilot became lost. The eventually came across the top of a office tower sticking above the fog, and they hovered nearby. The man attracted the attention of somebody in the office and held up a placard saying "where are we?", and received the answer "in a helicopter hovering 60ft above the ground".

The pilot said "OK I know exactly where we are, and set off towards their destination.
Later he explained "the answer you got was technically correct and not the slightest help, so obviously we were at the Microsoft help centre whose location I know".
Maybe ChatGPT is another help centre.

There are several attachments.
Some wheel heads are keyed on.
The driveshaft on mine has a taper that fits into the wheel head, which is held captive by a perpendicular pin.
...the stratagems for loosening depend on the attachment...

The first step in identifying what type of wild clay you have collected is color. The sample(s) below indicate the presence of iron (pyrite) simply by the orange/deep orange color created when iron oxidizes in nature. This is an odd sample because the piece on the left has visible sedimentation lines, that vary between a 1/16 and an 1/8th of an inch. In addition, the left sample has a solid brown color on top and the bottom; which is rather slimy to the touch. The thin lines obviously indicate a sedimentary deposit, and the slimy coating, which differs in color is silt. In further evidence of being silt; it washes away rather quickly under tap water; while the remaining clay is undisturbed. There are also gray/white areas on the top of the large sample on the right; which is commonly referred to grey gumbo clay in this area. Yes, it is clay; but its composition and structure makes it unsuitable for pottery. In this case however, the percentage is low; so whatever is left after washing, will remain. I will add 2-3% more silica to compensate for the instability of the gumbo clay.
What else do I know about this clay before I begin processing? I collected it in a heavily wooded drainage area; so I know organics are present. Although not plainly visible; there are visible black lines between the sedimentary layers, further evidence of organics. I also collected it wet, and after just two days; the pungent aroma of bacteria is already present. Yet, I also need to determine if the black color is only from organics. I also know that there are large coal seams nearby. In direct sunlight, I can see that the overall hue is darker than a normal iron pyrite color. From experience, this dark hue is most likely from lignite coal particles, and not organics. After I process it a bit; I will run a Split LOI test: if the lower test firing results in higher LOI numbers, then I know it is all from organics. If the higher test firing results in higher LOI numbers, then I know it is lignite coal particles. You only want to clean out sticks, twigs, rocks, and sand before you run a Split LOI test.
The large sample on the right is also revealing. It was taken just below the sedimentary sample on the left and bottom. This sample has no real distinct sedimentary lines, and the color is nearly uniform. Judging from the color; iron content is in the 4-6% range. How do I know that? On the left lower corner of the sample on the right side, is a 1/2” spot of deep orange/red color. That spot is nearly pure iron pyrite clay; which runs in the 8+% range. I know because of the color, and similar samples ran at labs. Natural iron pyrite clay will be lighter as the iron content declines, and darker orange/red as iron levels increase. My educated guess, that overall iron content will come in at the 5% range. I will take a knife, and cut a 3” square by 1/2 thick sample and throw it into a test kiln unprocessed to check fired color. It is advisable to use a waster slab, just in case; but you need to check if you even like the fired color before processing very much. I have several 1/2” thick samples which I broke in half just using my hands. The higher the iron and alumina content in a sample, the more pressure it takes to snap it in half. In this case, it took a bit of pressure to snap; so I an estimating 5% iron and 24% alumina. Yet understand that is based on snapping many samples, and many of those sample being lab tested for mineral content.
There is one more oddity in the right sample; did you see it? Directly across from that 1/2” dark orange spot, is a nearly black line. That is a solid line of coal; and that also means that the dark overall hue, and the dark sedimentary lines are most likely lignite coal, and not organics. Your sample will tell you a lot before you even process; you just need to learn what it is saying. Lignite coal particles means inorganic sulfides: which translates to blistering, bloating, or even black coring if not fired correctly. So now my clay sample just told me how to fire it. I will program a rate climb of 108F an hour from 1250F to 1800F to ensure all inorganic sulfides have been burnt off. Usually, a slow bisq firing program will accomplish the same thing. Take a real close look at your samples; they will tell you many things.
Tom
 
 

Ok, the question’s been out here a while, but I just remembered an epic screwup that makes me laugh and had to share. Not the worst , but probably the funniest. I was loading my kiln, it’s outdoors and dark, so I turned on the flashlight on my phone and propped it up on the bagwall. Finished loading, got the door bricked up, lit the burners and reached for my phone to take a picture. Where’s my phone? Oh noooo!!!

Hi Fiona,
Welcome to the Forum!
For colours, there may be some choices that are less expensive?
If making up your own slip from clays*, red, brown/buff and white are common colors.
Underglazes provide a somewhat inexpensive way to get a lot of color; they don't go on the same way slips do, but they do have their uses...
Stains may provide a way to add a few colors to your slip palette.
The per pound prices I'm seeing are $12-18 (US dollars).
At ceramic temperatures, metals persist and provide coloring.
Blue/Cobalt is expensive (but it's come down a lot).
Green/Copper is more reasonable.
Maybe start with just a few colours?
Paints typically have some titanium dioxide powder, which provide most of the paints' covering/hiding ability, and perhaps some metal oxide(s) for color.
It's all the other stuff, a lot of which will burn away in the kiln, likely including some of the dies that provide color that I'd hesitate over.
The resultant smoke and fumes from burning paints/inks are enough to advise against; how the materials influence the slips' behaviors could be of concern as well.
*I blend bits of clay with water using a blender.
It takes a while, but it works to get a smooth consistency.
Then I run the slip through a sieve to remove sand/grog.
I sometimes use red slip to decorate white and brown ware.
I brush, dab, et cetera the slip on when the ware is still damp - right after trimming.
The moisture softens the ware - timing and care can be important!
After the ware dries some, carving is an option.
Hope that helps!

I too would be very interested in such anti-gravity information, lol!

For the help with the underglaze question. Now, does anyone have a source for an "anti gravity glaze or clay" so when I drop a form it wouldn't  hit the floor and break...........
Again thanks.
Graybeard
 
 
 
 

It’s also helpful to remember that whether you’re using stains or oxides, you’re only adding around 10% or less by dry weight to a given recipe. So if you’re only mixing up a 1 kg (dry materials) batch of slip, you’re adding 100g or less of the given oxide. With powerful colourants like cobalt oxide, 10g or .1% in that one kilo is enough to get a very solid colour. The 10% number would be for some of the lighter coloured stains. Many of the darker blues, greens, black, etc I’d start at 3-5% and see if that gives you the intensity you want.