Bill Kielb

I think I would be very pleased to know the segment rate and after observing the delta graphically (or numerically) over time I would have a decent sense of how fast can this kiln go with reasonable accuracy and it would also be a strong indicator of element condition at peak temperature for me. Maybe less complex would be best for me and at a glance indicator of trend most useful.

When you run the dryer it exhausts 200 cfm, window open or not, so no, air will be drawn in from the many minor openings in the house. Opening the window even a very small amount will help ensure that you do not suck fumes back down the flue of a gas fired appliance though. Most old codes allow exhaust by volume …. if there is sufficient home volume to draw from. Most homes have leakage on the order of 5 air charges per hour or more. I would suggest you put your pm2.5 in the adjacent room(s) to get a pretty good idea if you are succeeding in exhausting all the particles generated by the kiln from the kiln room. Maybe confirm by noting the reading in the room vs the reading in other rooms. If the fan is large enough exhaust then the other rooms will remain at or near their baseline and change proportional to the activity in the other rooms as well as the pm2.5 outdoors. If you are a smoker, the counts will be crazy high maybe up to 1000 µg/m3 or more especially when you first light up. outdoor air will generally be in the single digit range for pm2.5 but can rise very high due to fires for which air filtration became one of the only ways to lower this count indoors. Your local weather station likely posts AQI and maybe Pm2.5 daily. For my location today, at this point they have measured in the last hour AQI of 29 and pm2.5 of 8 µg/m3 See below accuweather prediction for my location.

I think I would like it in the tool tip but not knowing what data are available may not be the best choice so I will review the Genesis tonight. This is a cool project, just wondering if a universal excel template might suffice. No matter - nice project.

If everything is intact, your glaze should be very underfired, but if it has stayed put and intact then I would test one piece in a cone 5 glaze fire. The worry would be if the glaze has come off or developed cracks that will not heal in the glaze firing. So as you remove those, very careful handling is probably really important. Firing a second time from cone 05 is very different than refiring. Right now your clay and glaze are not fully baked, so very different than a second glaze firing.

Much better! I would suggest to see percentage output from the controller if possible, by zone would be great, so at a glance I can tell if the kiln is under powered at some point or the controller PID needs some calibration and tweaking s practical.

So If you fire to cone 05, the clay will be bisque fired only, so porous and weak and the glaze will be severely underfired. The normal progression would be decorate with underglaze, then bisque fire. Then glaze with a glaze matching the cone of the clay and fire to cone 5/6 so the clay and glaze melt and mature as expected. I think the confusion here is the clay is not really firing at typical terracotta temperatures, it’s just called that and is a midfire clay that matures at cone 5. The good news is this may work just fine for a single fire to let’s say cone 5, just use a slow / medium bisque schedule but still fire to cone 5. Definitely something I would try and test. The clay should off gas and burnout as a normal bisque firing and then go on till maturity (cone 5). If your glaze tolerates the off gassing, then it will heal and be just fine when mature. Definitely worth a test IMO. This is often referred to as once firing and many combinations do just fine which saves one whole firing. Going slower than a normal glaze firing (bisque firing speed) is precautionary to allow enough time for the organics to burn out before proceeding onward to cone 5.

The underglaze is fine and will fire higher, specifically what clear glaze is on the piece? Velvet under glaze will basically go to cone 10 btw.

What cone is your glaze? The clay is basically cone 5 red clay so the glaze needs to be cone 5 for them to mature together. If you bisque this clay itt will be a fragile sintered bisque which most likely would not work well with a cone 05 glaze. So what cone does the glaze mature at?

Terracotta COLORED stoneware mature fires to cone 5. So I would glaze fire it to cone 5. I also would bisque to 04/05 but I think you. Have glazed it already. So maybe once fire to cone 5 using a slow / medium bisque schedule. Of course assuming you used a cone 5 glaze and not a lowfire cone 05 product. If you glazed with a cone 05 product and have not bisqued, I really don’t have a good idea other than remove the glaze someway and bisque fire to 05, then glaze with a cone 5 product. It is not functional and fragility may not be an issue, so trying one of them to cone 05 bisque schedule might get an acceptable result.p for now.

Might help, my experience as an old guy - oil burners are pretty old technology so lots of reading if you just Google oil burners. Some decent plain English reading here IMO https://inspectapedia.com/heat/Oil-Burner-Nozzle-Selection-Guide.php#FiringRate. Picking a correct pressure important, used to be no less than 100 psi which has grown to 140 psi for finer droplet size, better aeration. 140000 btu per gallon is how I learned it (no2) and nozzle dispersion critical to cover the firebox without impingement. Anyway, pressure, size, cone angle all contribute significantly and mostly really good filtration to avoid clogged nozzles.

Pictures definitely key here as I have seen circular failures and delaminating especially in bowls where the interiors were overworked in the green stage. Pictures and a little about any special throwing, trimming, ribbing, burnishing etc…. could help narrow this down.

If no need to be double sided - conventional masking tape? There are a variety of adhesives, fine line, etc, to choose from and they are available in different widths.

New elements for 240 v service and a bit of wiring change will get you there appropriately. Find the wiring diagram for your kiln in the single phase model and build / rebuild accordingly. If a transformer is in the kiln for controller power, chęć / change the primary jumper to match 240v. For breaker / wire size check the manufactures 240v model requirements.

Any hood is great, higher inlet better than low is good but really if you get it in the room, the room is small and to keep the odor from exiting the room, near the kiln much better than you are doing now. Keep in mind, the kiln vent is capturing many, just not all.

I would suggest running a quick test fire to let’s say a few hundred degrees. So 1 segment program, go as fast as you can (9999) to let’s say 500 degrees. All the relays will turn on and stay on till near 500 degrees. Ought to take minutes to achieve and you should see all the elements glowing. You don’t fire enough to intuitively know if what you are hearing is normal or not, so a quick test at least should show everything is working - or not. Do this without stuff in the kiln, especially wet stuff!

@MochiFriend Just to add a drawing for clarity

Make sure you pick the right model and control. The picture shows three different applications. You likely want the 6” round with the outdoor louvers. Airlift air shutter series

This will work, mounting the fan on the board to directly discharge, then run the duct in the crawl or wherever. With the fan mounted at the window all the rest of will be negative pressure, so no worries of small leaks. This is traditionally how we treat exhaust duct in general to guarantee no exhaust leaks out of the duct.

You might be interested in AC infinity. I have had them installed in several kiln rooms and model dependent they come with a temperature controller which varies the speed as required. Very quiet fans for the most part at what I think are reasonable cost. Google Ac Infinity.

Just a quick mention Neil makes a good point and without looking closer 8” combined is likely fine. Just a caution, while not the best it would be most correct to install backdraft dampers when combining exhausts so when one fan is not in operation the other will not have a short circuit path. Actually just best to run them out independently as designed. 200 cfm in 6” round is over 1000 fpm which is significant. This is not worth calculating really and to do so is a bit complicated and requires actual airflows. Separate discharges most goof proof solution.

@GestaltArtworks Yes, I am saying that and have found other colors in other brands to be difficult to melt over as well. It looks like black in that picture as well. Our common finding, especially prevalent over heavily applied colors, the color and brands varied. Since we have brush artists who want to layer colors and paint wysiwyg, meaning our final solution was to create a clear glaze with a bit more boron to melt over heavy applications of underglaze. And yes, we noted painting washes with the same color did not appear to affect the glaze to the same magnitude of heavily painted areas. The picture below is one we posted on Glazy for Marcia’s matte which is a matte glaze with a bit more boron to avoid these issues. Oops! need to add: The sugar bowl below thrown by me, decorated by Marcia and spray glazed by me was created under Madison pottery. It is a good example of some solid color combinations that were difficult to cover with clear glaze but essential to the artist to paint them as such.

I have measured these in operation, with all the small diameters and restrictions they do not flow more than 20 cfm. It’s rated 140 cfm in free air. Configured as downdraft it does not exhaust nearly that much. Old video here but measured from two kilns was less than 20cfm. https://youtu.be/etpa2Pc9Hug?feature=shared

No, if your kiln is outside then it’s already ventilated with outdoor air, so just open the door to the shed. We just want to suck more air out of the kiln room than we put into the adjacent rooms to do this correctly. The small kiln vent likely will not be enough to do this and again if it sucks too much air through the kiln, your kiln may not have enough power to fire so drilling more or larger holes has a downside. If your going to blow some air in, use your smallest fan on the lowest setting at the farthest window in hopes of being slightly less than the kiln vent while getting some dilution air into the office.

It really likely is not. We only think in terms of pressure.. To approximate that box fan is probably 150 cfm. The kiln exhaust is 10 cfm. You will be pressurizing all rooms to 140 cfm. Your kiln room will not really be negative and will become pressurized and remix with the office air. So the additional fan will dilute the office and kiln room which is helpful but also encourage leakage to all other rooms adjacent. More exhaust in the kiln room than supplied is how we make this negative. Ducting through the crawl space could be a neat solution.

Yes, box fans likely will cause an issue. The kiln vent is way too small to suck all that air out. a through wall fan close to the kiln more ideal. Just make sure there is always suction in the kiln room to be most effective. The only way to make something negative, you exhaust it outdoors. Intermediate fans likely will hurt more than help for the smell.