Bill Kielb

Hmm, glazed inside but not out will often stress the piece more. That could definitely make this more fragile and eventually even for the initial survivors cause sudden breakage months to years in the future. It’s not uncommon for a mug only glazed inside to one day reach its limit after a bit of use and shatter. Better if you could find an aesthetic acceptable partial exterior glaze or perhaps clear glaze solution to try and minimize this possibility.

I can suggest something to try, it has worked well for us, sort of an economical plaster batt so to speak. For items we want to dry evenly, keep their shape, and not have to risk flipping them, when possible we simply set them on a paper towel right side up. The paper towel wicks the water away and the bottom dries pretty much the same speed as the rest of the pot without flipping or handling. Started doing this with the cheapest of cfold recycled paper hand towels and never looked back since. Works great for anything you can remove from the wheel and place directly on a paper towel on a ware board. Doesn’t stick to the board, drys evenly, don’t have to flip it. Lightly cover to slow down the drying as needed. you might find a use, we never flip anything on its rim anymore until time to trim.

Just asking, do you mean an actual car kiln where the wares are wheeled in and usually fairly large say 9 - 20 cu ft and even larger? Sort of like the picture below:

I think compression is super important for this item. It’s low and flat so to me the bottom compressed from out to inward evenly is super important. Sidewall vertical as well as rim strike me as essential for this form as well. These cracks do look like the stress was generated during the firing as they were shrinking. So the question, for large flat bottom items like this as well as platters, do you fire on smooth shelves with grog or alumina underneath to prevent the ware from sticking and dragging during the firing as it shrinks? My early thoughts, really good even compression (not simply downward) at the time it’s thrown, not later and alumina or grog beneath during firing so it can shrink and grow easily in all directions.

Cast plaster is definitely not clay, it’s plaster. You might contemplate plaster / gypsum repair products then refinish with paint. Durabond products (not premix) adhere well and cure fairly hard, similar to plaster. Any plaster repair product is likely fine though. Clay: a stiff, sticky fine-grained earth, typically yellow, red, or bluish-gray in color and often forming an impermeable layer in the soil. It can be molded when wet, and is dried and baked to make bricks, pottery, and ceramics. Ceramics are fired to high temperatures to melt them creating permanent ceramic products. Plaster: a soft mixture of lime with sand or cement and water for spreading on walls, ceilings, or other structures as in castings to form a smooth hard surface when dried. Plaster is not fired it hydrates and cures to harden.

My reading is the on / off switch was turned on, else there would be no PF display and it would be blank. I think the “safety” switch referenced is the on / off toggle switch.

I don’t believe they make 40 amp receptacles or they are uncommon, 50 amp is common. It’s ok for connecting items and wiring to be rated more than they will carry. Not less though else the 40 amp breaker will not protect them and they become the fuse. #6 awg cord is common and fine to be overrated. The cord has conductors next to each other in a confined space so it will heat up more and, it has to remain flexible over its life so good practice for the cord to be sturdy and over rated as well as the plug and receptacle. I like your thinking and would normally suggest if it’s financially feasible for the exact reason you state. Besides it will reduce the voltage drop which puts more power in the kiln and less heating in the wire even if only a minor amount. You need to get the breaker size right though to protect everything appropriately. Neil mentions the not less than 125% nor more than 150% of the actual kiln load for sizing in North America because electricians often are not familiar. Since you are running cable, last mention - whether 6/3 or 8/3 mąkę sure it includes an earth ground, JIC it is needed, it is there. For this kiln you need ALL 4 wires.

Definitely get a fuse as 4 ohms is very strange. Post a close up picture of the glass fuse if you get a chance. Follow the troubleshooting / instruction in the manual or as Peter posted to see if you can exit pf mode.

Yep, (I’m that previous replier) if you direct your husband to the Link and page I cited he will know. Technically if you are using non metallic cable it will be 8/3 with a ground. And heavier if it’s a long run. Please be sure it’s copper and follow your local codes as well as use a four wire 50 amp plug and receptacle if not direct wired. here is the spec from the link above (p6), once he sees this I think he will know. If not, for a continuous resistive load as Neil mentioned everything is sized at 125% which is why the manufacture says number 8 and 40 amps. Follow the manufactures directions and local code and my comment about this being two 120v circuits a neutral and ground and you should be fine. Here is a link for the wiring diagram as well. The neutral IS essential. https://paragonweb.com/wp-content/uploads/A82B_A823B_A81B_A88B_AA8B_AA8B3B_WD_PL.pdf PS for voltage drop the rule of 3% is excessive for kilns. 1% or less is way better.

Your instruction manual is here https://paragonweb.com/wp-content/uploads/IM5-A-and-B-Paragon-Inst-Man-Jan2017.pdf page 6 outlines the electrical specifications which you should confirm matches the data plate on the kiln. Your electrician will need to refer to these requirements which appears to be 40 amp two pole breaker and number 8 wire (minimum). This kiln requires a 4 wire circuit so: two phases (240v) one neutral and a ground makes four wires. Your electrician should size as specified throughout and wire per code.

A fuse should read 0 ohms or infinity if bad so 4.2 ohms is very odd. What strikes me is pf means power failure, but it seems like you are having a continuous power failure with this kiln yet you did not mention a tripped breaker. My best guess is this kiln is plugged into a 120v receptacle instead of a 240v receptacle. Just a best guess though based on what seems like the odd measurements you are experiencing - can you confirm it is wired to an appropriate 240 volt receptacle? Here is your instruction manual - tnf 66 troubleshooting starts on bottom of page 33 I believe. https://ltt.arizona.edu/sites/ltt.lab.arizona.edu/files/LRG Paragon S. SnF %26 TnF Series Intruction and Service Manual.pdf Here is your kiln wiring diagram for troubleshooting https://paragonweb.com/wp-content/uploads/WTNF66.pdf Finally this kiln should have a very specific plug to differentiate it from a 120v plug

4321 is not a bad recipe to try as far as clears go it has a very established history. You may have success with it. Just an FYI, in general - For reduction you primarily will be concerned with oxides that are reducible so: iron, copper (generally with tin) easily reducible for new colors - heavy reduction = cobalt, nickel, chrome, manganese and hard to reduce In a studio kiln = vanadium and titanium they tell me (I have never reduced either). Glazy.org is a nice resource to scan through. Digital fire has several base glazes as well and is a great resource IMO.

Like most in clay, both can work and both can have compatibility issues. Unfortunately testing all together (including your glaze) is the only solid advice I can give.

Nope, there are hundreds, thousands of them out there, hence tough for someone to suggest a single one. 4321 has a long history, is easy to make and gets you started in what I believe a helpful direction Have you gone to Glazy.org? You will also find many other formulations there as well and maybe can try those. Colorants / oxides I would try any and all colorants in concentration, combined, etc….. color to your taste as they say. It likely does not match my taste. If you do go to Glazy you can also look at the effect of various colorants as well so you can try the ones pleasing to you first. Hence the suggestion I gave you. In reality there is much to learn about glazes as there is not a single good gloss clear. They are “your” clay dependent, “your” firing dependent, available local materials dependent and so on. Learning about them takes time and testing but also is very rewarding.

For now might I suggest the simple view that the tin is essential for copper reds and it is chemistry ………not colorant. If you accept that then reduction is simply attained by a really dirty carbon monoxide rich atmosphere with very little oxygen to reoxidize things so to speak. From there most all reduction is a combination of reducing things to create a color or carbon trapping for effect. So my most consistent Raku pieces were reduced in a bucket lined with plain old newspaper, inverted in a tub with a few inches of water to seal out air. Once I figured that out it was much easier to compare recipes and changes. Dead leaves, organics ……… I found newspaper did the job consistently just fine. So the common reducibles: copper, iron, tin (with copper, prox 3:1), nickel, cobalt and manganese. Common effects: reduction colors, iron acts more as a flux and turns black, carbon trapping, crackle (a glaze flaw) and horse hair etc…. Experimenting is still one of the best ways to learn though, for sure. I have spent a lot of time getting smooth reduction from all parts of a kiln. Even reduction that does not reoxidize is very important in kilns and Raku. Don’t let air in is what I learned and copper red is a decent indicator of how you are doing.

Bottom relay, or ……. Two or more elements are open. Unlikely that two elements are bad so relay that goes to the bottom element is bad. Good time to measure each element though and write it down since this is a combination series parallel wiring arrangement. If their resistance has increased by 10% or more, time for replacement as well.

Hmm, pretty broad request. I suggest go to Glazy.org on the web and search 4321 cone 10 and see if there are versions you like - as a start to your journey.

Some folks make a color pallet painting a stripe of all their underglazes then covering 1/2 with their clear glaze and fire to cone so they have a reference with how each underglaze changes with a specific glaze applied over top at a specific cone. One big test tile, many colors, one, two, and three coats half covered with your favorite clear. Amaco and Mayco also have samples already made and there are sites that have examples. One such: https://www.thestudiomanager.com/

Are you familiar with the Orton cone chart and making the last segment go the speed in the chart for the final 100c of the firing to get the cone to drop? The center column speed is common so your last segment speed would be 60c per hour and for cone 5, end of firing = 1186c, start of final segment: 1186c - 100c = 1086c. So last segment starts at 1086c, goes 60c per hour and ends at 1186c. This should get cone 5 to drop as planned. your first segment can go as fast as your pots will tolerate so approximately 100c - 250c per hour. It turns out, most of the heatwork is done in the last 100c, so get that right and you can more accurately fire to cone. If you add a hold to the end generally a 15 to 20 minute hold drives it approximately to the next cone. This way, you always have a place to start working on a “good” schedule.

Sorry I do not, but you can search Glazy.org under the advanced search by a color. You should be able to save as a picture and post here under choose files \ photo library …….

@Mudfish 2320 is more like cone 10, especially with a hold. If you have the three key Bartlett it can be set at a maximum 2350f for a high limit. I would highly suggest you record your firing schedule to include gas pressure, damper position, time of adjustment, how fast your temperature has risen since last measurement. For the most part folks monitor and adjust approximately every 15-30 minutes. End the firing by observing witness cones (using proper protective glasses) not by temperature. Recording all that stuff will start to give you a feel for how firings progress and you will be able to repeat results more easily IMO. How long did this firing take, and it likely made near cone ten but hard to know exactly without witness cones. since these wares are intended for food consumption you may want to consider, is your clay fully vitrified, are the glazes food safe and are they durable. Generally pinholes / blisters are a no go defect for many potters when the ware can hold food.

We have used the recipe with success! On occasion we add a tiny bit of clay so when bisqued the decoration sinters and is pretty sturdy to work over. A few pics of some items we have created as Madison pottery a collaboration by Marcia and I. The first is a very simple airbrush application on a fully functional giant perfume bottle to get a specific color and specific ombré shading. This is definitely easy to airbrush. Marcia (My better half) submitted it to an international perfume bottle competition one year. I re-made the top btw to lose the drips before it went. The second is some hand painted UG with simple highlights. It was done with underglaze and bisqued to ensure everything stayed in place to completion. The third is a bowl done with a similar recipe as you described with a touch of clay added. Maybe they will spark some ideas for you. Just to add, for the forum we each have written permission from each other to display in whole or part especially for educational use.

Pretty much use your standard techniques for highlighting and shading, I never wiped my airbrush art. Color mix can make things easier, mask techniques fairly common as well. It definitely takes practice and getting used to spraying underglaze but pretty easy to infill reliefs, wash, blend and highlight free hand. Regular air brushing techniques are fine and depth is something that can be achieved. For newbies I used to start folks out with spraying using simple masks and several shades to build their skills and confidence. Quite common to use stains as a colorant in many glazes BTW, It might prove an easy (fairly inert) way to change the tone. To fill in low spots you may prefer underglaze to that of stain just because it will stay on the pot better than straight stain.

Hmm misread this or it changed. The prior speed can be anything you like and your wares can tolerate. 100c - 250c range is common. Glaze firings generally can go fast. The heat work put in before the last 200c (to be conservative) in a glaze firing is fairly reversible. Bisque firings on the other hand generally take longer and depend on time and temperature to burn out all organics

Hmm, if you condition the space, which for winter you will need to do then very low relative humidity levels will exist and you will need to learn the speed that stuff drys. If you arę used to 75% relative humidity then you are familiar with things that dry slowly so summer (even conditioned) should be similar to what you are used to. Freezing is a no go for sure so definitely plan on heat for comfort and workability. Lots of folks fire outdoors and yes some controls will not function till they are heated above freezing. This is often solved with a brief warmup with a heatgun or hair dryer. You will definitely need to experience the seasons though at your conditioned comfort level. The relative humidity will definitely affect drying time, and your level of conditioning for comfort will affect the relative humidity.