Bill Kielb

Having seen this now, my inkling is extractor in a decent drill impact for the setscrew. The wheel head screams pickle fork (ball joint separator) and appropriate number of C washers to hopefully pop the head with minimal damage and hopefully no damage to the shaft. Gotta have a replacement head ready though. It’s an idea!………

Min has a great point especially if it does not perform well. It’s hard to change the weight of the glaze that way, unless ….. it’s not stirred really well. So if you are just skimming water off the top when measuring, make sure it is mixed well and not a whole bunch of ingredients are at the bottom of the bucket.

Most glazes thicken over time if the water is allowed to evaporate. My thought is this was mixed with a lower specific gravity at some point. You could allow this to evaporate to get to a preferred SG. It’s a commercial glaze so no way to know what is in it and if it likely will perform as expected without testing once restored to your preferred SG

An interesting thought if you have never done any sort of pottery maybe take a course or two if possible, to see what you may like. Learning to build a gas kiln and operate it reasonably proficient - maybe a year or two. Learning and becoming proficient in all aspects of pottery - maybe a lifetime.

It’s a wheel, at 2.2 amps you are free to use most any three wire extension cord. So 3 wire 16/3, maybe 15 ft is rated well beyond your wheel. I would change the receptacle it is plugged into to a gfi receptacle with appropriate cover from weather. You can buy a cord with the gfi built in, but they are fairly pricey. I would not use this outdoors unless protected by a GFI though. A GFI can only protect you if the cord has all three prongs and the wheel has a three prong plug.

My experience with carbon trapping, most dependent on the firing cycle. Very fine soot during the cycle readily is trapped, sometimes uniquely because water has randomly splashed on the object which has attracted the solubles to spots on the ware. The mistake I see made most often is in the reduction firing. Generating too much soot in the firing (not good) rather than fine char usually points to poor technique.

I think all thats been mentioned above are great. I would add from an expectation standpoint If you are constructing a fuel fired kiln especially for a first time, there will likely be a decent learning and testing curve. Great fun and usually very educational for those that persevere and succeed.

I would agree. Most often when elements run out of power you will see it in a very significant deviation of the final rate, significant extension of the final segment timing ………. followed by the errors. You will know in advance before this happens with your level of observation for normal element wear.

If I understand this, you programmed for 108/hr and actual firing it achieved 120/hr. Further you programmed 350/hr and it actually achieved 344/hr. My initial thought is it was operating at the Precision it could. In the 108/hr segment (more overshoot in the algorithm) and in the 350/hr segment maybe a combination of what it could achieve power wise and undershoot in that segment. So my initial thought is many times programs do not fire perfectly at the rate programmed. Quite often when rates are programmed that exceed the actual power available they really go a lesser rate. How well a controller matches temperature throughout the firing is dependent on several programmed characteristics in the controller. One would be relay cycle time. My experience, kiln controllers do a pretty nice job of matching the kiln characteristics so those actuals would not alarm me. It would tell me though for that loading, you don’t quite have enough power to maintain 350/hr, very close though and you have enough power to maintain 108 degrees per hour in the final segment. The final segment to me is most important as that is where you are providing significant heatwork to match the Orton columns of maturity. Orton says this starts 200 -250 f from the desire peak temperature (in the Orton chart) The ten minute hold, Ireally can’t speak to, maybe you were trying to drive this 1/2 cone higher. People have all kinds of schedules that work for them, often very different and much more complex than just following the instructions In the Orton chart. The big question to me is did it fire to the cone you were seeking?

It sounds like your power source is not able to supply all elements in parallel. A 2400 watt element with 240v across it draws 10 amps. 20 of these in parallel would be 200 amps. That would be 48000 watts of heating energy. Very large home kilns are approx 12000 watts of energy. Each element right now should be 24 ohms as you have designed. So my sense is when you connect several of these in parallel whatever power supply you are using has a severe voltage drop and they do not heat up as expected. I would combine these in series parallel to get down to 12000 watts which means an overall resistance of about 5 ohms. Unless you have built the biggest kiln ever, 48000 watts is too much. At 12000 watts your power supply will need to be capable of supplying 240 v @ about 48 amps without significant voltage drop.

Don’t fire on drywall it will smolder and burn once calcined. Used to be type X 5/8” - approx. 60 minutes, 120 minutes to sustain a flame. I like the shelf idea and unless once firing, you can grog / silica the shelf after bisque. Many of our large format sculptors would build on a very straight shelf on top of a four wheeled cart.

I do not have a preferred store purchased overglaze. I spent a whole summer trying to resolve this for our cone 6 glazes so our artists could paint freely with most underglazes. The solution was to modify a clear with a bit more boron to more completely melt. If this is your issue then testing other commercial. over glazes as well as lighter coats of underglaze are probably your best bet. I have never noticed a difference between clays but only anecdotally tested on the variety of studio clays used at the time. Color, thickness applied and even underglaze supplier had the greatest effect - all reasonably resolved with a slightly lower melting temperature of the modified clear. Not all under glazes will go to cone 10 as well with significant color change often being the effect of higher temperature. All our artists, especially sculpture test their underglazed for color. It was not uncommon for a sculpture artist to say, I need to stop at cone 2 - no higher as the perfect color of a full sized human bust that took them a month to make might change from what they wanted. A bit tedious, but an example of all tested in advance.

In the UK the declared mains voltage has been 230v single phase I believe. North America uses 240v but split between 2 phases ends up at two 120v circuits to neutral. I think it would be odd to have 120v available without your very own step down transformer. Check before buying for sure to be safe. Check a light bulb or two - ought to be rated at 230v in the UK.

Pictures for sure for ideas. One experience - Not all clear glazes melt well over underglazes so the underglazed decorated area can be locally refractory. The end result for this defect, bumps, orange peel, glaze that does not cover and melt well to a smooth finish. Often mistaken as over fired and bubbling. Additionally if heavily underglazed, when applying glaze over the top the underglazed area is far less absorbent than naked bisque so it can be hard to apply glaze over the top evenly. Spray applying overglaze and drying is one way to get a pretty even coat over the entire ware. Pictures for sure here as there can be other reasons for sure. Most underglazes need to be tested with their overglazes in the manner they will be used to be reasonably sure the combination works as intended.

Hard to know the formulas for sure of commercial glazes but there are many sources for glaze recipes. Glazy.org is one web resource. Making glazes for many potters is a thing though, often to save on the high cost of commercial glazes but also often to design glazes that are very durable, to their coloring and finish preferences. You can browse glazy (and others) for something that might be similar.