Bill Kielb

Post a picture or two of the cracked handle and mug.

It could be different, the only way to know is test fire and do an absorption test. I still don’t understand why it is making it through the glaze though. Maybe some really fine crazing but I would expect to see that in the stains. Do they use witness cones to confirm? My only thought is the glaze and clay likely are not mature. Maybe someone here will have a better thought.

just an FYI - I am not aware of any end of fire holds in their cone fire schedules. Usually adding a 15 minute hold drives it to the next cone.

I can’t help wondering …. I assume it’s glazed and can’t help wondering if this isn’t just a coffee stain that comes off with a little scrubbing similar to my glass coffee pot which gets a nice cleaning with a mr clean eraser about once a week to remove the light staining. Having said that cone ten clay fired to less than cone ten usually ends up less vitrified and more absorbent. Looking at the graph for this clay though it’s roughly 1/2% from cone 8-10 so not bad. For the clay you can always check by doing some absorption tests. My question would be more of why is the glaze staining? Of course the glass in my coffee pot stains and it is pretty durable glass. If anything I would make sure the glaze is a reasonably durable composition which can be tested as well. Folks often make durable liner glazes just to be sure their food wares are as safe as practical. If the stain scrubs off, then is the glaze durable and are we scrubbing off some glaze or is it as durable as my glass coffee pot? if the stain is embedded under the glaze, the glaze is likely not very durable.

Cool, seems like you ruled out all the possibilities and actually glad it’s type K. Sorry, just recently had a gal use a type R for an S or Vice versa - very confusing. You likely gained a bit of power by pulling all the old switches out and certainly gained some consistency as I recall it was on a downhill slide of making less temp each firing.. Now I think it’s time to run the cone fire program just to see what it will do with its current available power and have the controller compensate as necessary. You can still run your drop and hold at the end I believe. Maybe gets rid of the babysitting issue and lands on a cone. And yes, any type K it will perform basically like any other type k sleeved or non oo you determine it’s just a bit under powered and you want to squeeze more power out of it then anywhere there is a bad connection or voltage drop will be wasted power. I usually use an infrared thermometer to quickly see if one terminal of like loaded terminals is running way warmer. If it’s 20-50 degrees warmer then worth checking the connection. Cord ends, receptacles and even one side of a breaker will heat up if the connection has loosened I have found all the aforementioned at one time or another actually. . This would be tweaking and I would not expect a large gain unless you find something pretty hot. Still a fairly quick way to keep an eye on things.

I think I would use both and that’s me just being extra cautious. To me It looks heavy and the edges will bear firmly on what they are placed upon. It’s a nice piece, wouldn’t want it to get caught on anything.

my thought- This would be a candidate for a cookie or waster underneath for me and alumina at the intersection of all junctions so nothing binds as it shrinks, above and below the cookie. Setting this on paper towels or newspaper as it dries definitely let’s it shrink nicely as it dries as well. Fire on a nice flat straight shelf.

Hmm, interesting, Type R or Type S? And is the controller programmed to match? If not it definitely causes issues because the profile between the two is enough difference and a proven way to over fire things. Many manuals make special note, especially type K to type R. Generally a thermocouple won’t make your kiln slow down in its firing and slowing down means you are running out of power to keep up with the ramp. Since you have a type K to test with though, I would definitely change it, make sure your control is set for type K and also just run a slow glaze cone fire program to see if it will follow those speeds reasonably. Type K most often just break before they drift too much. I am not a fan of custom programs without sound reason and even less a fan of holds because often the kiln can’t really keep up with the custom program and it’s tough for folks to know the actual rates which eventually often leads to what appears to be random results At least in cone fire mode the controller will compensate for the speed. First I would verify type, programming and even room temperature. The type should be stamped on the thermocouple, make sure the internal programming matches. Type R & S can look the same and often have no specific color for leads in the US. They do have slightly different profiles though so if found programmed in error would require another test run with the appropriate type programmed into the controller. I would also run a cone fire program (slow) the expected speeds are reasonable. A thermocouple is just two dissimilar metals joined together and they become a battery that supplies a minute voltage. They can drift over time but eventually break and just quit producing a voltage. Type R & S excerpted below, note the minute difference in output, which insidiously get larger as temperature rises. The difference in output is not necessarily linear through its range which can make temperature and speeds appear odd when mis-programmed and generally a sure fire way to mess with your controllers (and your) perception of temperature. Last observation, since your thermocouple is in a metal sheathe, make sure the metal cannot contact adjacent kiln metal especially as the kiln heats and expands. This can generate electrical noise or in the case of a grounded sheath can cause all sorts of random issues as well. A very final thought - as potters we generally don’t think in terms of peak temperature but rather rates and time at temperature. Since our reactions don’t begin until there is enough energy for the fluxed reaction to transpire the heating work beforehand often has limited value with respect to maturity. Rate in the last 200 - 250 f degrees is super important to maturity and holds at peak drive the heatwork towards the next cone because we are in the midst of the fluxed reaction. Cones are made of glaze, they visually show the heatwork attained in the zone of maturity.

Nice work, easy to give up. Way to stick with it! Hopefully you are all set.

Yep, looks good.

That will work, in essence take both wires from each element group and extend them out to the electrositter. Two wires from each element group, two output posts on the sitter. Meaning you will be bringing 4 wires to the electrositter. Make sure remaining splices are tight and also make sure the wire thickness is the same. Very important as the connection to cycle the control relay could be lighter gauge. I doubt it, but it could be which would be a reason not to use it.

I would submit your kiln may draw 48 amps @ 240 v nominal so 11520 watts max. You will need a 60 amp breaker and wiring to satisfy the limitation of loading a breaker 80% maximum. From there you can add your other loads and characterize them. The AC being the toughest to start on the generator. A 3 ton Ac unit might run on approximately 15 amps but it takes 5 times the current to start it or 75 amps. So a simple 3000 w load grows to an Effective 9000 watt łoad at startup with the AC unit. A general rule 5 times the amps, 3 times the watts - at startup. My point, inductive loads are killers, hard on everything including the grid because of a power factor less than one. Resistive loads are fine, but their true wattage must be accounted for. The cure for the AC used to be a hard start kit installed on the AC unit (Big capacitor) because at 5:1 on startup you quickly run out of capacity with most generators. Tell your generator guy what wattage your kiln is, he will size for it like most other things - to cover the wattage.

No, I am not confident. As an example there is nothing connected to terminal 7 and you have it being installed on the electrositter. Maybe best way take a context photo showing your elements and the wires leading to them. Step back a couple feet and get them all in the picture. Then we can annotate that so there is no confusion. Right now it’s too hard by description only. The terminals marked zero (0) and one (1) only turn the relay on.

Yes, if it’s whole house then the breaker will need to be sized for 125% of the kiln rating but that is to protect the breaker and ensure the breaker is never loaded more than 80% of its rating. Again, all about the breaker. Large inductive loads (like.an AC compressor) are very hard starting on a whole house generator. Kilns not so much except it will be lots of watts for many hours. What is the rating of the kiln (watts & amps) and what is the generator rated (watts or kva) The generator will need to be sized for the watts, not necessarily 125% that’s only a requirement for the breaker. When kilns start and stop, there is little inrush. Quite opposite to that of a large motor starting so it is fairly gentle comparatively. Your generator will need to be rated to supply all the watts for the home though and if you have an older ac unit, etc…. Be sufficiently oversized to start the AC unit and all the wattage being consumed by the home. A 10,000 watt kiln is very similar to an Electric stove. Easy to start, just lots of watts.

Hmm, I need a better way to do this. This should be your relay including the numbers. The wire on terminal 6, connects to the wire on terminal 8. The wire on terminal 2 connects to the wire on terminal 4. You should be able to take a picture and include the numbers which would allow us to confirm. You are only jumping out this relay so the elements are powered all the time your controller sends power to the kiln. The relay in the controller will cycle everything on and off as it needs to. I am assuming your kiln is wired into the controller. The middle elements are powered by the top infinite switch. If you have jumped H2 to L2 and H1 to L1 on that switche then you have jumped out that switch as well. Whenever power is applied to the kiln all elements will come on full. Again pictures would help confirm. To add - finally noticed your drawing link. The bottom two connections on this relay cycle this relay on and off. The top infinite switch cycles this relay when turning on the middle elements. You can disconnect and insulate so this relay doesn’t keep firing after it’s jumped out.

If this is what you mean: in the drawing below connect 1 to 1 And 2 to 2. Top to middle. Follow the path of the red and the path of the blue. When the relay activates this is the path taken. In other words jump out the relay.

It sounds as if you have started the kiln and need to troubleshoot. To that Duncan made this general manual https://aakilns.com.au/pdf/Duncan_Kiln_Service_Manual.pdf which covers some of the the how to for their kilns in general. Can you tell us a bit about the model, model #, wattage, voltage, picture of the equipment tag, how it’s currently wired such as size breaker, etc….. and anything else such as if you know all the elements are glowing ….. post a picture if possible, I think that will help folks to ask questions or make suggestions. operation manual here if you do not have it : https://paragonweb.com/wp-content/uploads/LX851_Duncan_Energy_Saver_Owner_Manual.pdf

You really don’t need the relay in the kiln so I would jump it out. If the contacts are worn it only saps power from the kiln elements. The relay in your control will turn everything on and off as necessary

It should evaporate, but I would thoroughly wash and thoroughly dry just to get everything off. Oil from hands etc….

knowing that, I guess I would jump out all the connections of the infinite switches with good solid connections, including the magnecraft relay and disconnect the timer - no use for it running.

No, you may be perfectly correct but if either of the infinite switches do not go full on or their internal contacts have any voltage drop including the relay, things become random. The thumb wheel timer is powered in the off cycle of the magnecraft relay and the on cycle of the lower infinite switch which mechanically affects the top infinite switch. Way too much stuff and connections for me. Now that you have a real controller everything goes and I install my own 12vdc relays controlled by the Genesis. One for element set 1 and one for element set 2.. The loading on each is approximately 12 amps which is light. Mount them in as cool a location as practical and they last a long time. The sitter can stay as a safety or eventually be jumped when you have confidence in the controller. Since these are graded elements you should operate as a single zone. IMO: too many items to depend on acting correctly, too many connections. If you have a controller no need to have all the extra complication. The Genesis controller only has outputs for 12vdc at low current so it does need relays to function. And is also powered by a 12/24 ac center tapped transformer so I am not clear on how you have that wired. Other than a 12 vdc replacement relay for the old 240 vac magnecraft. If so, is the timer connected to the NC contacts of the new 12vdc relay? I think I just upgrade this to how modern kilns work and simplify it.

Sorry saw this earlier and just could get back to it now. Looking at the schematic of this, I would suggest you remove the thumb wheel and infinite switch(s) and replace with relays. I believe that is causing your random results. If I read the specs correctly your kiln was 24 amps and a 30 amp breaker and minimum #10 gauge wire was suggested. Diagram I found FTX23 and FX23f. https://cressmfg.wpenginepowered.com/wp-content/uploads/FX23F-FTX23-220.pdf Could not find FX23P though.

Assuming this is currently in the bisque stage now, The acrylic paint will melt and burn. My best thought is wash off the glaze. Wash off the acrylic with solvent then re- bisque the piece to remove all traces of acrylic. Start over, ceramic products only - (glaze) this time to decorate. Acrylic comes off porous surfaces with alcohol, lacquer thinner, acetone.

I would assume the top has the most surface area and is less insulated than the sides so likely larger shell loss than the sidewalls and maybe first or close second to the floor. More surface area still I would think than the floor. The 4” raised shelf on the floor should also help a bit as well. it’s really hard to know your speed from the graph, any idea what you fired in the las two hours.? I don’t understand the units off time on the graph actually. I would like to see a picture of the firing setup, one power burner, two? Flame centerline will determine the heat distribution as almost all the heat at the end of the firing is radiant even though you are moving a lot of hot air, the volume of air and it’s ability to retain substantial heat is very small in relation to the radiation. The effective centerline will be a function of the burner physical location and it’s effective height depending on operation. Generally when going in reduction It raises a bit. Post some pics of the setup, hard to speculate on position and clearance without seeing.

Seems like a nice bit of research to be had. Share your tests here if possible, it looks interesting.