Hulk
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Posts posted by Hulk
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i) Motor well protected from corrosive kiln atmosphere
ii) Adjustable plenum
If you are considering moving your vent setup to a larger kiln in future, choosing a "stronger" fan for your 1.4 cubic foot kiln may make sense*.I bought an inexpensive inline 100 cfm motor for my setup. It's strong enough to pull a stream of superheated atmosphere from my 7 cubic foot kiln and is still working fine after a few dozen bisque and glaze firings. When it fails, I'll look at replacements that do not have the motor hanging in the vent stream! Although the superheated and no doubt rather corrosive stream of kiln atmosphere is mixed with ambient air in the plenum (the box fitted against the kiln), it is still corrosive enough to wear away unprotected and/or susceptible materials...
*the stronger the fan pulls, the greater/larger the ambient port in the plenum "should" be?
I'm saying yes.
An adjustable ambient port (aka "bypass" port) in the plenum allows for ...adjustment!
A stronger fan allows for more dilution of kiln atmosphere and sizing up in future.Added: Reasonable trade off between suitability, quiet, long-lasting, price, likely looking at well over a hundred US dollars.
Added II: This might be a starting point
Jabsco 35115-7020
Searching that ^ string will generate related hits. Note the flange specs.
Max inlet and ambient temps, ah, that might be a red flag.Added III: Jabsco 35515-0010 max inlet temp is higher, 130°F
Added IV: both Jabsco models, above, turn a fan in the vent stream, however, the motor does not. The commercial solutions I see use similar fans...
When my cheap inline freezes up, I'll be shopping! -
Good question Greg.
I'm sorry I don't have an answer.Storage where the wares aren't visible can be more challenging. heh.
Ah, Callie's post just came in! Good questions.
I'll add, when and why will you be taking wares out of storage (an extension of Callie's first question), and how many (one, a set, a representative sampling, ?) at a time?
Marking the containers with strings* that correspond to files** might streamline the process, cutting out printing and affixing images.
Mainly I just wanted to bump your thread...
A way to get rid of ware, err, make room for new wares ...has to be part of the plan!
*string - names! Your naming convention(s) could be descriptive/helpful?
Whatever is important to you could be included (within reason, err, up to a point), class/shape, size, clay, glaze, pattern, date...
e.g. six inch bowl, red clay, Clear Blue glaze, 2022, A1 "grade" - B6RCB22A1
...I'd think about naming conventions for a long while afore committing...
Containers having a similar class/shape of wares, from a particular era, finished similarly, could cut down on searching.**files
images, renamed to match the ware names
text file, sortable might be handy, so spreadsheet, perhaps a line entry for each ware, where each line has columns for any data you might want to sort/search on... -
Hi Ann,
Welcome to the Forum!
You might check with Skutt.
Their support is very responsive and helpful - when I had questions, a real (nice) person answered the phone.
Check their hours...I had a year model 1983 1027 for several years.
As I recall, the sections lift apart.
They connect electrically via plugs -between the red boxes - which you will see when the segments are separated.
I'm not sure if your kiln is older or younger.
Skutt has some older manuals available via their website; try this one?
KilnSitter - Kilns | Ceramic Pottery Kiln, Glass Kiln, Pottery Wheels | Skutt -
Resource favs:
Tony Hansen's site, a treasure of detailed info; here's the articles list Ceramics Technical Articles (digitalfire.com)
See also blog, recipes, glossary...This Forum!
Note, any closed/archived discussion topic isn't included when using the internal search feature*.Susen Peterson's book, The Craft and Art of Clay
Functional smoke detector(s), fire extinguishers;
Kiln glasses;
Be home any time the kiln is over 452°F (or so)...*"External" search, from your favorite search engine casts a wider net; try including https://community.ceramicartsdaily.org/ in your search string, e.g.
https://community.ceramicartsdaily.org and Hulk and "kiln schedule"will return open and closed topics...
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Cobalt is cheaper today than it was ~five years ago.
Hope petalite price drops, still $10/lb (or more)... -
Second seven cubic foot electric has been test fired to cone 5 (first bisque later this week maybe); it's brand-new touch screen three zone Bartlett/Genesis controlled*.
I fire to cone 5, oxy with downdraft fan, 100°F drop and hold after peak, controlled drop to 1850°F with fan on, then all off.First kiln was a manual, three segments, each with Low/Medium/High switch.
Initially, I watched cone packs through the peeps; later on, I checked cone packs afterwards and just watched the pyrometer during.
I set the sitter with +1 small cone - which almost always dropped at about the right time - for a safety backup.
I'd kept notes on each firing - times, temps, cone packs, results - which I'm poring over now, for upcoming firings in the new kiln...I was so sure that gas was the only way to go!
However, there just wasn't a place to set one up at our last house (there isn't a place at our new house either); I'm happy with electric.
Both power sources have shot up in cost over the last several years. We have enough solar here to run everything and then some - new system went online last month - that helps a lot.*Per others' shared experiences, I'll be closely monitoring cone packs as the kiln reaches target! ...for the first several firings.
Looks like the new kiln's pyrometers read ~35°F lower than my portable; although the portable very likely reads the same as before, I'll be watching a cone pack through the peeps!
...with appropriate kiln glasses on, o' course, against harmful rays any any flying bits... and make adjustments from there.Everyone I've spoken with that has gone from fully manual to full auto loves the clickety-clicks.
I love the clickety-clicks as well! -
I'm using several of the profiles depicted*!
For more vertical lidded jars, something like #1;
bowls, generally like 2 and 3;
for drinking - glasses, mugs, tumblers, cups, etc., something like #4,5,6, where the recurve is slighter, but perceptible when the eye is level with the rimAn elderly gentleman's son asked about designing a bowl that would assist his father in loading his spoon, so, the "helper bowl" - where the wall curves in somewhat at the top, which isn't particularly helpful when one tips the bowl up to drink from, but it does help with loading the spoon ...and guarding against spills.
Several variations of lidded forms have a more severe incurve, e.g. the teapot.In general,
trying "work" the rim only as much as necessary, this from trying to limit the bumpy/gritty feel that sanded/grogged clays exhibit when the finer particles have been worn/washed away;
encourage accumulation of slip on the rim - leaving a bead of slip when ribbing off the outside, same when sponging out then smoothing up the inside;
definitely distributing the slip evenly (somewhat) with the chamois as a final step on the rim proper**;
smooth the rim of slip on the inside with a fingertip and move the pull-off mark down a centimeter or two;
smooth and shape the outside just below and up to the rim with a frosting spatula;
use the same spatula to reduce the rim of slip into a spiraled tool mark;
post bisque, sand any burrs smooth***;
after pour in/out of liner glaze, dip the rim to accumulate a thicker layer of glaze on and just below (on the inside) the rim****;
wax, cut, and sponge the liner to outside glaze transition (per Tony Hansen's "Liner Glaze" article and video clip).
Raw wares:
The frosting spatula which is a favorite tool. It was used here to smooth and shape the outside wall just below the lip.
That's where the lip "parks" - a critical surface, imo.
In the case there's a ridge of slip at the bottom of the arc, I'll use the spatula to form a diminishing spiral down the side.
Wow, the camera "sees" more that I do! The rim treated thus will usually hold a nice bead of glaze.
Here there was a rim of slip below the rim band, hence the diminishing spiral ...which matches another bowl from yesterday's session.
*Currently; there's been some evolution - there may yet be more.
**A potter named Adam makes the point in one of his YouTube clips that the chamois merely distributes ("...dispersing that damp clay...") slip; to smooth, burnish, "compress" and/or tool the clay, he uses a strip of plastic bag, which removes the slip and smooths the rim. Perhaps leaving the slip does weaken the rim? idk
***outside, with shop vac and mask for me, buckets of rinse water, time, sun, and wind for the wares
****even the stiffest glazes seem to move down a bit, especially at the rim -
Interesting! Thanks to all contributing to this thread.
My guess, given the amount of Boron in my glazes (that contain MgO), the MgO is (likely) all melting, early, per the previously mentioned eutectic.
However, fully melted may not necessarily mean "active flux" as in lowering the melting point of Silica and Alumina.I'm still reading "refractory" as not melting/melted.
Words!
From "DOE Explains" article, "A catalyst is a substance that speeds up a chemical reaction, or lowers the temperature or pressure needed to start one, without itself being consumed during the reaction."
Chlorophyll (green in plants) is certainly the first catalyst I'd heard of; the bead coatings in catalytic converters also comes to mind - cars were being fitted with them some forty-eight years ago...The term "flux" as used in ceramics/pottery for glaze, clay, etc. may be different from the worlds of metal - soldering, brazing, welding, smelting.
...err, certainly is different! Wikipedia has a nice long article on Ceramic Flux; MgO is listed.
The term in medicine (never mind!), math, physics, general state/status, magnetics/electrics - and more! - each somewhat distinct.
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Thornton's article lists three Boron Magnesium eutectics; this is the lower temperature one (last column is °C)
MgO·B2O3 Magnesium oxide and boric oxide MgO 36.6, B2O3 63.4 988 If I'm reading right, the Boron melts much much earlier.
If I'm reading right ii, my low COE liner glaze has enough boron to melt with the MgO...
My low COA liner glaze looked clear to me - before I started adding Zircopax to it.Now I'm curious and interested (again); what's melting the seventy + moles of Silicon? almost eight moles of Alumina?
I'm not getting the maths.
P.S. Hope the dinner was smashing Min!
...was just trying to remember the last time we had that many guests -
I had the same question.
The lid's hinge has an adjustment for expansion/lifting, which needs to be adjusted properly to avoid undue stress to the lid?
The rod wasn't quite down tight like the image above; when re-assembling, I bumped it up (the bracket thing) a bit beyond where it was (will find out how that works soon!).I sure like the notebook L&L provides (documentation), also the online articles and vids.
Good-oh! -
Hi Debbee,
Welcome to the Forum!
Just wanted to add, please be sure that lid opens all the way - comes to rest in the open position without leaning against that wall.
If the lid were to fall shut, well, could be bad. -
Tony Hansen discusses some mid-fire electric options in this article: Reduction Speckle (digitalfire.com)
There are several commercial glaze products that speckle.
I'd tried clay that speckles (Laguna WC403) and liked it very much!
The spots appear through the glaze and, bonus, on the raw clay surfaces as well (at glaze temps).A speckle recipe on Glazy calls for a small amount of "granular ilmenite" which may be worth exploring.
See also:
Ilmenite (digitalfire.com)
Manganese Granular (digitalfire.com)
Granular Rutile (digitalfire.com)A variation of JohnnyK's suggestion, pick up a small amount of glaze with an ear syringe, hold it such that the glaze is on the verge of dripping out, but not quite, squeeze the bulb to get a spray of fine droplets. ...discovered this by accident, I'd used the syringe to glaze the inside surface of hollow knobs - fill, then suck out the excess, boom.
Practice first, as Johnny suggests.
Be sure to rinse out the syringe for next time! -
Cement tile backer board seemed too rough, although I hadn't considered sanding it off to smooth it some.
We're putting up cement siding board at the boy's house, hmm, the back (smooth) side might scuff off smooth enough to make a good bat?It's stiff, should be fine with water and otherwise generally durable.
How it holds up to tools, that would seem to be "the rub" - I'm off to try it now....
That's how wide the planks are (just over eight inches), so diagonal holes work.
For medium and smaller wares, np.Here I was ready to go the rib, so, about to cut away that bit of smeared out skirt, which did serve well enough to protect my finger bits from the bat, which is still rough. I used my least favorite wood knife - one I use most, heh; it becoming a nub sooner, that's maybe a drawback.
The material is absorbent enough that getting it damp to start is a thing, like plaster, but not nearly as pronounced.
I liked it well enough to make some more!
The edges need to be cut smooth and clean, err, cut as clean as possible, then cut back and sanded.
A few passes with the sander smoothed the surface a lot! It still abrasive though.
The other side is embossed with a woodgrain pattern, so I'll consider these one-sided bats.A coat of durable finish of some kind might serve - giving up the absorbency but cutting down on the abrasiveness.
Lightweight, very rigid (some of the plastic bats flex, which can wonk a tall ware), flat, thick enough to hide the pins, easy to make.
I'll update after a good long test run...- Pres, Kelly in AK, Pyewackette and 2 others
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i) Saw a throwing demonstration, wanted to learn how to do that; decades later, enrolled in "Wheel I" then "Wheel II" at local Junior College.
ii) Clay and glaze materials bought from pottery supply stores, in person as much as possible ($hipping costs!!); a mix of second hand and brandy new tools and equipment
iii) It can be lonely, as others have mentioned.
The Studio space in our previous home was almost always very comfortable; the Studio space in our new/current home can be overwhelmingly hot and bitingly cold! I look to have that sorted by next Spring!
Both Studio spaces are also bike shops. Some people (me) have too many bikes in the way! In our current home, repair and maintenance projects that aren't pottery or bike have been regulated to the non-Studio side. Hope to have the wall up by next Spring.iv) ...have been thinking about this one!
There's surround sound with broadcast radio, streaming radio/podcasts/etc., and library music/podcast options already.
I don't mind using the amplifier's remote, also don't mind walking over and getting some clay on the controls; it wipes off ok!I'd like real-time feedback on the work in progress profile, height, width, and thickness on a screen - that could be helpful!
I have to bend way over sideways (else pick up the bat) to get a good look at the ware's profile. Hmm, mirror?
Stopping to measure the height, width, and diameter of the opening takes a moment.
Thickness can be measured, yes, but that takes a moment as well.Although practicing to the point where stopping to gauge the profile and measure the various bits isn't really necessary - just for confirmation - it is possible* - how nice would it be to have feedback on a screen?
I'd like that, but not so much that I'd try to develop and test a system...
The height and width wouldn't be terribly difficult, nor the profile, but thickness, that might take some doing!
*possible for some, not all of us can do repeats within a half millimeter without measuring.
I can sometimes repeat without measuring, but not dependably enough, I have a stick, caliper, crossed stick, six inch and fifteen inch rules (w/ metric), hand square, and a few things I'm forgetting as measures. -
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Hi C Walker, welcome to the Forum!
That looks like "bloat"
Clay can puff up like that when whatever it is that's gassing/expanding is trapped.At bisque temps, perhaps the bloating part could still "breathe" and hence doesn't show.
When I had some bloating, it was more in the thicker parts, however, I also thought there were problem bits here and there in the clay that were at issue.
Trimming down the thicker parts and extra time soaking at about 1500°F in the bisque fire seemed to help, and fire to just cone 5 (it was a cone 5 clay).Watching against thick sections might help.
Giving a long bisque fire with plenty of oxygen might help - burn out the gassing bits.
Firing just up to maturity and no more could also help, and not too fast at the end.Surely you'll get more input, check back after while.
Nice colors, pattern, texture -
Good question!
My guess is the clay softens just enough to overcome the form, where a cylinder or even an open shape - bowl - has enough structure to resist collapse, your four twisted ribbons of clay cannot, so.
Perhaps if the four arms had some arc, and no twists, they would stay upright.
You might try using a prop - a narrow cylinder - to hold the form upright, where the interface isn't glazed and has a bit of kiln wash or somewhat to prevent sticking. Even so, the twisted ribbons may still sag.
Good luck! I'm curious to know how your project comes out.
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Good question!
I don't have an answer, mainly just wanted to give your thread a "bump"...
...and suggest trying your insurance company again, as you might get another person on the line.
As for the building department, my guess would be that permits and inspections for any alterations/additions (electrical, plumbing, etc.) would be of interest to them.Meanwhile, for your consideration:
new smoke and CO detectors;
functional primary and secondary ventilation*;
correct wiring, including proper fusing/breakers;
commitment to attending throughout each firing - the entire time the kiln is over 451°F;
placing new/serviceable fire extinguishers at the kiln and all approaches to the kiln.*primary: powered kiln vent that pulls a tiny stream of superheated kiln atmosphere from the bottom of the kiln and pushes it outside via a dedicated vent
secondary: overhead system that evacuates hundreds of cubic feet per minute via dedicated ventingimportant note for both: provision for "make up air" is critical - air must be allowed "in" to make up for what is being pushed "out"
Hope that helps.
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Hi Frogesan,
Welcome to the Forum!
Kiln wiring comes up quite often here.
The experts (I'm not an expert...) point out the 125% rule, etc.; try using the built in search using "125%" to find a few, e.g.
https://community.ceramicartsdaily.org/topic/31343-skutt-822-wire-gauge-size-vs-breaker-sizeAs for burning down the garage, going with a too small breaker should just result in the breaker tripping, nuisance trips!
Running too small a wire with too large a breaker could get hot, I believe (I'm not an expert!).
For reasonable run lengths, #6 wire, correct?
And for runs much over fifty feet, start looking at the next bigger wire?Any road, the kiln manufacturer's documentation looks correct to me, and it lines up with what the more expert regulars on this Forum say.
The wiring for my new 48 amp kiln was recently completed, 60 amp breaker, per specification.
I only needed the two hots and a ground, however I ran the neutral (and left it capped off on both ends), just in case someone comes along years from now and needs/wants the 120v, having recently ran into a similar situation with our son's wellhouse (wiring for 240v well pump), where we wanted 120v to run some water treatment equipment... -
Most everything like the seven.
The glazes I'm using don't move much.
The slight groove at the juncture of the wall and foot does serve as a glaze catch, however, I'd started doing that to make it easier to get a sharp glaze edge*.There's a spiral mark between the chatter marking and the edge of the foot, which could help as a glaze catch.
The spiral and chatter marks are mainly for interest and to provide a bit of texture for grasping.
The foot ring itself provides edges for fingertips, particularly for washing (slippery!)...
* I tape the foot ring off with masking tape.
Tooling the top edge of the foot ring provides a nice sharp line to tape to.
The tape gives me something to hold on to when pushing the ware down into the glaze.
I pull the tape whilst the glaze is still damp, much less dust, and a cleaner edge.I'm dipping the outside glaze(s), upside down, hence controlling the glaze layer near the foot ring is straightforward.
- Pres, Pyewackette and Rae Reich
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I'm not finding any images where I can see how much room there is to work in.
Any road, wire wheels and cup brushes might serve? I've used both to restore rusted steel doors, frames, etc., driven by angle grinder, seven inch grinder (careful, that's a dangerous tool), drill motors and Dremel tool.
Be sure to wear gloves, eye protection and thick clothes against the flying wire and rust fragments! Protection against the noise and dust would be important as well... -
The 1170 °C/2138°F eutectic I'm seeing in Bloomfield* is "Calcia" - the "Magnesia" (MgO) is 2471°F.
Any road, very interesting; my first read into anything beyond the general idea**.
My low expansion liner glaze clear (clouded with Zircopax, so clear-ish) has .279 MgO, Unity, from talc.
Before I started adding Zircopax, it came up clear.
The Pottasia, Soda, Lithia and Calcia eutectic temps are all below my Cone 5 target, but the Baria and Magnesia are well above Cone 5.
Are there more layers of complexity with multiple eutectic happenings? Looks like it's melting well.Ah, the Thornton article includes a eutectic with MgO and Boric Acid that's below 1000°C, per Min's post.
Interesting!
*Bloomfield_May17CM.pdf (lindabloomfield.co.uk)
**things that melt at a higher temperature by themselves can melt at lower temps when mixed with certain other materials.
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The soaking can't hurt!
As for the pitting, any chance the clay(s) have changed at all?
Do the glaze recipes Laguna do for you include talc?
Just curious... -
Nice color!
From the linked page: "Absorption at cone 06 is 10.8% and at cone 6 it is ≤0.1%"
^ I'm interpreting that as
a) cone 06 is the lower end of the bisque range and
b) cone 6 is near the upper end of the glaze fire rangeFor functional work, low absorption is better.
One percent or less is good, very good.
QotW: What type of floor or floor coverings do you have in the shop?
in Int'l Ceramic Artists Network (ICAN) Operations and Benefits
Posted
New and former Studios, cement slab flooring.
I'm wearing crepe sole mid-high work boots when it's cold, somewhat supportive flip flops (Sperry Top-Sider) when it's hot, slip-ons with groovy insoles when it's medium.
I work more sitting than standing. I get purple toe (Raynaud's) fairly easily, so keeping the feet happy is important for me. Wool socks, an extra layer at the ankle (cut off the feet part of worn socks, voila! ankle warmers), watch cap (warm head->warm hands and feet, try it), and insulated foot pedal all help.
Yep, the heavy cast alloy foot pedal draws off A LOT of heat! I've taped a layer of bubble wrap to the foot pedal, voila ii! right foot gets much less mad ever since.
I'm having pain in the L 4-5, a bit better yesterday, much better today.
Hope you are feeling better soon Min.