Bill Kielb

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.

Hmm, several issues and lots of dynamics in a gas kiln so hard for me to provide a specific answer. If you provide more details of how you fire, what you fire, how you load, a little about the kiln, are you reducing, etc… folks here will likely have ideas. To name a few issues re: firing evenly Number one on our list of even firing would be final speed you fire in the last two hours? Number two on out list would be flame centerline and flame path which may be influenced by damper operation. Number three would be where are the kilns greatest losses from the shell Bubbling glaze / pinholes lots of causes but peak temperature and a faster than normal cool down with a possible remedy of down firing or it’s equivalent may help with problem glazes. lots of speculation here, share more info and folks will likely provide constructive feedback. Maybe a picture or two.

As others have said, paper clay is not necessarily shock resistant, and can be less dense in the end. I have made micaceous products and they are relatively porous and mostly coil and scrape and lots and lots of burnishing. Not really flame ware. I also experimented with flame ware and low expansion clays and compatible glazes just for the use. My take, the flame ware works and most items were made relatively thick to be durable especially for direct contact. None of that rings of slip casting to me though. My suggestion is try some flame ware to see if it even fits your envisioned process and produces a durable end product to your satisfaction.

Thanks the bowl is only a test bowl to get an idea of performance as it pools. This one crawled. Just an FYI if it helps……... This glaze started out without boron as a Bristol glaze (typically zinc, 0.2-0.4 in a 0.7 RO base) and actually used rutile which added more random coloring. The desired result was tinting or subtle refraction of blue / violet and it did this fairly well without boron. It was designed as a true matte and boron was used to make it a bit runny ( much less tan 0.15 boron at cone 6), so runny matte crystals produced the subtle refractive color or hue. we spent most of our time removing zinc and experimenting with titanium rather than rutile to get more repeatability. It was fairly consistent and controllable in small ranges but was very sensitive to temperature in the end. 1 full cone over fired would make it go very matte and very golden. Post what you discover if possible, it was a fun glaze to experiment with for a summer and played well with many other glazes.

Sorry I can’t think of a simple way to remove the sodium chloride effectively. I am afraid they are right.

@EarthToMatthew just looking closely at your new switch, it is seven lead. - follow the table described above. Ark-less to Gottak. If the Gottak has changed numbers / letters you will need to go to their website and correlate to the old number / letters. It appears to have enough leads.

So follow the table in the link above or table below: The old lead L1 ark- les, now connects to the ‘a’ terminal on the new switch. The old lead N connects to the ‘b’ terminal on the new switch. The old lead L2 on the Ark-les connects to the ‘e’ lead on the new switch. Go though the table from top to bottom and you should be good to go. If you bought a 3 way switch instead of a four way, you will run out of wires, your switch needs to have 7 connections. It appears the Ark-less is missing the #1 connection. I need to review both to see if there is a way to use a three way in place of a four way. It’s not likely though. Next easiest and usually cheapest is to replace both with infinite switches but will take some skill getting the connections in order or get a four way switch.

The size of the pipe required is dependent on operating pressure (11”) equivalent length and how many BTU is necessary to carry. It’s generally easily picked out of a table in a conservative manner. The table below is for low pressure with 0.5” or less pressure drop under full rated flow. In short to ensure 290,000 btu at nearly 11” in the 20 equivalent foot range it needs to be 3/4” ID.

From your pictures it appears you have two different switches currently installed in the kiln. The black maybe an Ark-les and the red maybe an ivensys. IF TRUE then you will need to follow the conversion chart lead for lead in the link above. Nice crisp well lit photos of the existing switches AND the new one would confirm that for folks here and allow for clear helpful direction. I did notice several questions above have gone un answered so I am just curious if the kiln wiring was confirmed as having a neutral, ground and two 120v circuits, have you measured the element resistance and what were the measurements (your elements in the picture look very spread out, so maybe worn) and how did you determine the switches are at fault, other than the corrosion - do the elements fail to sequence as expected? The red switch appears to be a replacement and in good condition.

This may help, spent one summer working with Bristol glazes at cone 6. Fairly similar recipe as posted with the simple concept of taking a titanium matte and making it a bit of a runny matte to capture the refraction of the crystals as they accumulated. End result blues and violets and a touch more towards red / yellow with a tiny bit of iron. Variations around the zinc base and melting point more so around the amount of boron. Some samples below, if this is the look you are interested in I will attempt to locate the trials I have and post.

He can change the amperage of the breaker, but not really the volts to 250v. Are you tripping the breaker? If so, what size do you presently have? Here is the info I have for a TNF 66 kiln, per the manufacture, it may help. 240v, 20 amp 2 pole circuit breaker. Definitely get the electric right. Your electrician should confirm with the nameplate on the kiln as well.

The epoxy, top picture. Squeeze out on in a mixing area or on a mixing pad you can throw away, mix thoroughly for 1 minute then apply everywhere you need it, even to fill gaps. Set items together accurately and wipe all excess neatly off with mineral spirits or similar.

Interesting late notice when looking at the Duncan service manual. 208 v elements are 8.66:ohms which places you at 6000 w when operated at 228v which is 26 amps. Here that current draw would require at least a 30 amp breaker and number 10 wire rated for 30 amps. So gauging the elements down but having them wound as if 208 v could be a reasonable solution to the low voltage.

gas hoses and pressure regulators.com this one is stainless and does require quick disconnect though. Getting all the parts to fit up is usually the issue as this is premium low pressure and the quick disconnect is a great feature but you will need to match up everything for connection which will take a bit of reading and matchup. Mr heater probably does not service large btu loads.we should sketch it out to make sure everything fits end to end really. The regulator pictured will require a 1/2” mpt to 3/4” fpt adapter. Anyway, depending on your regulator we should draw everything out to make sure sizes and gender matchup.

Amazon? Internet? I have used these with good result.

Ok, so there are two pressures we need to address so let’s see if I can describe it so it makes sense. The pressure needed at the burners has to be approximately 11 “ (INCHES, less than 1/2 psi). Regulators used for this purpose generally have a maximum inlet pressure of 10 psi and reduce it to 11” (Inches). Also the regulator must be capable of supplying at least 290,000 btu, which means it will likely have a 3/4” diameter or larger outlet size at 11”” of pressure. Capacity problem 1/2” diameter hose /pipe at 10 psi can easily carry 500,000 btu over many feet of distance 3/4” diameter pipe / hose at 11” of pressure is needed to carry 500,000 btu 10-20 feet so the usual choice (most economical and lowest pressure for safety) is to hard pipe from the kiln with 3/4” pipe to where the gas bottle will be (within 20 ft of the kiln) and install a two stage propane regulator at the propane tank. If we do that we only need ordinary gas pipe from the kiln to the bottle, a two stage regulator (economical) and a flexible connection from the pipe to the second stage regulator (pigtail). So a quick rough drawing And some parts, economical regulator (horizontal mount) A safe removable way to connect the regulator to the tank leaving a low pressure short pigtail to connect from the piping to the regulator which need to match 3/4” pipe thread on one end and whatever our regulator outlet thread is, once we pick a regulator.

Typical two stage regulator for RV’s are rated at 160,000 btu and generally are 3/8”. To simplify this, How many btu is your kiln rated (nameplate). For that matter what kiln model and maybe post a picture of what you are hooking up. A barbecue tank is usually 20# and has 4.7 gallons of propane full and can produce a bit more than 400,000 btu. If your kiln is 100,000 btu per hour, that’s about 4 hours of firing on a barbecue tank. So 15 gallon may be a typo, or maybe not. I posted some tank examples below just to give you an idea. Give us name plate, pictures, make, model etc………. this is something likely easily solved but confusing to pick if you have not experienced it before. Folks here can help. This likely is easy and economical using RV style stuff which are mostly 2 stage regulators, which you likely need.

Sorry to hear that actually. 3% rule of thumb here is usually allowed but for kilns for obvious capacity reasons less is suggested. No point in starting with a brand new kiln in effect worn 3%. There is a special rule for continuous resistive loads to protect the breakers from repeated heating in North America. The rule here would be no less than 125% of the rated load and not to exceed 150%. Often this takes care of the voltage drop issue, a nice side benefit. Most countries address these loads similarly to protect the protection devices so you may want to research. Electricians not used to working on kilns are often not familiar and tend to under size things. Most often the rules for maximum loading on a breaker fit well with this standard. So for example, here for normal breakers you are only allowed to size them so normal loading does not exceed 80% of the rating. Which, interestingly is the reciprocal of 1.25 or 125%. Actually intuitively who would put a 30 amp load on a 30 amp breaker? It does happen though. For your use you may want to have elements re-wound to make the original wattage at your rated voltage. (Total kiln R= V(squared) / Watts) Of course all protection and wiring would need to be upgraded as necessary and I would suggest clear re-labeling is a must. BTW we just went through this in another thread and as an FYI, kilns with 4 watts per interior square inch are usually most robust. Hope that helps! Previous thread : https://community.ceramicartsdaily.org/topic/30261-paragon-dtc-800-kiln/?do=findComment&comment=228236

Probably the most important part - your method works for you. I will say that excess pressure out the lower burner port lines up with a bit too much restriction or reflected flame in the flame path, especially if your kiln is not pressurizing from the top down. Under normal circumstances folks find a suitable gas pressure then begin closing their damper very slowly until some pressure (flame) exits the lower spyhole and they are in heavy reduction. With the restriction in the flame path it sounds like you will need to free this up a bit, it likely is too restrictive. One thing at a time though.

My feeling is the burner port size confirms you were going in reduction because of lack of secondary air. And the better performance seems to support that result as you were able to fire faster because your burners put out more. subjectively, To me I like the use of a shelf as your bag wall so it becomes a glowing red hot radiant panel and enlarges your flame trench a bit especially in a small kiln. I like the wall to be significantly less mass that the wares in the kiln. Also to me my next try would be with the target brick to the right or up against the right hand wall to provide some deflection forward and because of the coanda effect it still will drive about 1/2 the flame to the rear and to the right wall of the kiln. One thing for sure, I have rarely been able to solve by changing multiple things. It’s often too dynamic so unless you get lucky with first placement it makes things really hard to solve. So whatever changes are made I think one at a time is the most effective way to creep up on a solution.

just to keep the brewmasters at bay: I think that’s a really solid assumption. It can be less for a mixture of things in water but those things would need to be a lower sg and miscible in water. A real world common example likely would be alcohol. For clay, I can’t think of anything light enough so to speak.