moonzie

Several months later I found I had to use this kiln in a pinch for production untested. Luckily, it seemed to do just fine. The bisque firing it did was all under-fired but that wasn't a big deal. I've read that you should put a cone 6 bar in the Dawson Sitter to fire to cone 5 in this big ol Duncan. These bars were not Orton brand - came with the kiln who knows how old they are. It flattened all of the large self-supporting cone 5 witness cones - like really smooshed it. It did this in about 11 hours. The bisque only took 8 hours I think. I did another glaze fire this time I just put everything on high fire from cool with an actual Orton brand 5 bar and all my witness cones appeared underfired, maybe hit cone 4. Anyways.. I'm pleased the bones were healthy. Curious as to why in the electrical diagram the safety relays are AFTER the SSDs... I'd think it'd make more sense to put the safety mechanism closer to the source of power.. ? I still want a bigger L&L but wife says we have what we need with this one lol.

We have some whole 8-sided Cordierite kiln shelves that we used for both bisque and glaze firing at least 200 times with no warping or cracking issues. I even had to cut a few down with a diamond blade since they originally went to a kiln with 2.5" brick and ours is 3". They've even been dropped a few times a few inches. I believe these are 5/8" shelves. But going to Advancer shelves was a game changer for us. 90% of the time, if the glaze runs on a pot too much I can save it with the advancer shelf. On the older Cordierite shelves, even with kiln wash, I think I had about a 40% success rate of removing the pot without damaging it. Not to mention how light and how thin they are which is important in our little 2.5 cu ft L&L. In fact, it's better to not use cookies with the advancers. I like to experiment with glaze layering so I feel like they've already paid for themselves in saved wares! One caveat... over time, the Advancer shelves WILL get stained over the course of many firings. And that stain will permeate other works. I tried the silicon carbide sanding wheels from Menards - nope. I even ordered some special silicon carbide wheels from Advancer. Those did better, but did not completely clean. What worked was a Bosch turbo diamond cup wheel (from Menards) on my angle grinder. It took some time, but it came out MUCH cleaner. Wear a respirator and hearing protection. I don't use kiln wash on the Advancer shelves.

Checked all around for any loose wires and found none. Replacing the relays solved the issue. I completed a fast fire last night in just over 5 hours. I'm still curious about this tho. I've always assumed mechanical relays will usually fail on or off - not in between. But if they half-fail like mine did, then aging mechanical relays it would seem can impact fire times. As they wear, would carbon buildup on the relay pads substantially increase resistance to the circuit?

I suspect the relays may have around 350-400k cycles on them. What's the lifespan of mechanical relays? I went to Indy and picked up some Skutt relays that are the equivalant. Going to install later when i get home. Can partially failing relays cause extended fire times? I feel like when i tested for voltage at the element block last night i was getting 60v across the two posts and the lower one had 80v but i cant quite remember...

Howdy y'all! I replaced the quad elements on my L&L e18s-3 earlier this year and they've seen about 50 firings so far - all with no issue. I usually do medium fires and they take 7-8 hours. Last night I was doing a fast glaze fire and noticed a big difference between upper and lower zones - about 300 degrees hotter in the lower zone - over 1300*f below and just barely over 1000*f above @ 7 hours into the fire. Checked again at 7:45 into the fire and the lower zone was 1600 with the upper around 1200. Noticable color difference between the upper and lower zones looking at peep holes. I ran some diagnostics and with my digital ammeter I found the upper zone was only drawing .2 amps while the lower was drawing 11. My outlet voltage was 245. I had voltage present at the upper elements when the relay was engaged. I started a cool down program to run the vent fan. I checked this morning. All appears normal. ??? Amp draw is around 11-12 amps on both elements. Voltage still good. No signs of arcing or burning. Elements read around 10.2 between upper/lower halfs and 19.8 across the entire element (quad). What gives? Help! Jason

Ooo I like the idea of using a pair of mechanical relays connected to a safety output! Or maybe just a beefy double pole single throw relay. The SSRs I ordered are rated for 50a so they should run a bit cooler. That Duncan is only a cone 8 kiln so I'll probably just use it mainly for bisque fires with the occasional/rare glaze fire for extra large pieces. Lots of elements to maintain. They all appear good but I've got a few new old stock parts on-hand it came with just in case. A part of me wonders if I'm going too far if this is going to be a mostly bisque kiln. I had to calibrate a kiln sitter once on my wife's first kiln (an old L&L from 1971) and I hated it lol. That kiln was never right after she over-fired it one summer.

It will have zone control yes. I've got a full size Genesis controller (the older one). I might build a wall mount box. I might just put it where the kiln sitter used to be and use a case fan to circulate ambient air. Not sure yet! I suppose a wall mount would give me more modularity. It's big. ES1020-1 with the added ring on top.

Specific to type K, is there any difference between the Ceramic Shop brand and L&L brand TCs? Gauge size/life span? I'm purchasing parts to convert an old Duncan to digital. Already ordered a transformer and some Crydon SSRs from Mouser.

I usually put large stuff on the bottom so it's got plenty of surface exposure to the elements down low. I did notice last fall that when attempting a fast fire, it still took about 7 hours and the set point was off from where the kiln was at by at least 20 degrees. Usually I do medium speed glaze fires unless I'm in a hurry. The first time I did a fast fire, it only took about 4.5 or 5 hours. Maybe it was just the TC then? I thought the closed TC tubes extended the TC lifespan by quite a bit. Guess I was getting paranoid about the elements. Still learning!

TCs were the originals from when we bought the kiln factory new. They were very blackened and charred looking. The bottom elements read 20.0 ohms (however accurate a cheap Etekcity meter is) I didn't measure the top before I pulled them. Originally, the elements measured 19.2 and that's what the new ones measured. Always 04 bisque slow. Cone 5/6 with various holds of 2-15m. There were a handful of cone 5 Crystal Blossom (Laguna) fires with 3.5 hour holds in there. The last glaze fire I did this program. The next fire was a cone 5 glaze with 4 minute hold. It errored out just before peak temp and unfortunately, I didn't have witness cones in this load but I tested for vitrification and only one piece came out not fully vitrified. How many firings do you usually see quads last for? I spoke with a L&L tech by phone and he said they typically see about 180 firings on average. I've been watching the screen where you can see power output and for a good while now, the bottom stays on 100% sometime after 1200f. The error occured when the top was 2190 and the bottom was 2130, but think my TC adjustments are just a touch under value (reading cooler than what it is).

Howdy y`all. I've got a small L&L E18S-3 with quads. After 192 firings, I got an error ED50 Too high above set point. After reviewing the last error details, I realized the time had come that the lower end could not keep up anymore so it was time to swap out elements. Took me a few hours longer than I expected but I got it done. I also swapped out the closed TC tubes with L&L's newer open ended ones since I was having a hard time dialing the kiln in with solid repeatable results (we pack it pretty tight). Also replaced the TC with the standard types. Q1: How far should the TC tips recess into the open tubes? I set mine back about 3/16" Q2: I'd like to do a seasoning fire with some shelves and maybe a bunch of stilts in it and some large witness cones in front of the peep holes so that I can dial in the adjustment all in one fire. Would this be acceptable or should I do them as two separate fires? Thanks! :)

We have a drying cabinet that we have some incadescent bulbs in. We have some oil clay that we put next to that bulb for 24 hours and it actually softened up and became useable again. But after about a week it became too stiff to work with again. Try warming it up. Might come back to life.

Just to update anyone else who might find this helpful... I ended up actually drilling 4 1/4" holes in the bottom of the kiln and 4 in my home-made plenum box below the kiln. This provided enough ventilation that there was almost no fumes detectable during the firing, but a air-quality monitor we purchased recorded the air quality as being "poor" still (not sure what the PPM count was). It definitely was working much better than my original setup. The temperature of my exhaust vent pipe was around 135-140*f as it left the kiln and went up the wall towards the fan. Btw, that little crappy hydrocrunch fan did die after about 100 firings. Replaced it with a cheapy unit from Menards. We've since purchased a small dedicated kiln shed 8'x12'. I'm in the process of getting it wired up. We also have a big ol Duncan we picked up that's 27"x29" for $100 that's in good shape. I'll be gutting it soon and converting to digital. I'll need to purchase a new exhaust motor (Dayton 1TDP7) and then recalibrate it all. We've done just over 150 firings on our little E18S-3 quad kiln and it's just starting to slow down. Fast firings are taking about 6.5 hours where it used to be 4.5. New elements, TCs and open-ended TC tubes are waiting to be installed. Figure I'll swap it all out when the elements have breathed their last. I've always had some difficulty dialing in the firings. We always pack it quite dense. It's either over or under per the witness cones. Hopefully the open-ended TC tubes will help with this. Cheers!

I was recently told by wife and father in law that if we opened up the hole from 1/4" to maybe 3/8 or 5/16 it would draw better. I'm concerned that it'd draw too much.

Would this be an appropriate motor? https://www.grainger.com/product/DAYTON-OEM-Blower-1TDP7 On the specs it lists 110cfm @ .5" sp but I'm not sure if that's differential or.. well however else it's measured. overall?

Yeah those squirrel cage fans are going to be a lot more capable of 'work' in terms of creating a pressure difference. I was reading some ancient mailing list threads from 1998 where somebody was complaining that a Bailey vent system with no bypass componentry didn't work at all but a L&L system that had a bypass worked great. That they tell you your vent system works great when you put a flame up to the 1/4" hole as a test is why I've been confused. It's much more complex than that. And most people probably just buy the kit, plumb it all in and call it done. There's a level of science to this that I suppose was taught to me at some point but have since forgotten. My dad was a HVAC business owner and I worked with him but I never sat down and went into ventilation design theory. I'm sure he'd school me if he were still around. He passed on in 2013. Thanks for the help guys! I'll post an update after I've modified a few things.

Thanks, guys. I'll try popping out a few more holes in the collection box and see if that helps. I can always seal them up with HVAC metal tape if it's too much. If after I've got 8 hole drilled and there's still no change, I'll look into a different fan motor. The unit's only 15 watts. With no ducting attached, it moves quite a bit. I just wish this stuff was documented better!

Thanks! I didn't realize that it worked from the venturi effect. I thought it just worked by negative air pressure pulling a suction. Maybe I was mislead by L&L's own documentation on this... https://hotkilns.com/sites/default/files/2021-11/ventsure-instruct-print-11-1-2021.pdf On page 5 under The Smoke Method, Step 2 reads "Start with the bypass valve in the fully closed position. This will give it the maximum suction in the kiln." And further up on Page 5 under Operation Step 5: "Use the flow control on the Bypass Box to modify the flow of exhaust - a larger flow control opening reduces the flow of exhaust fumes from the kiln, and a smaller flow control opening increases the exhaust." So this is why I've been running with no inlet vents on my collection box. I figured I'd start with max suction and see how it performed. And I was just going by L&L's own documentation. Maybe this logic applies to larger kilns with multiple downdraft holes? I only drilled one 1/4" hole in this e18S.

I started a bisque fire last night and did some testing with a stick of incense. With the lid closed, bottom peep hole plugged, stick of incense inserted fully into the top peep hole and kiln vent on, you could see it drawing the smoke down except for when the elements kicked on it would burp some smoke out. This was while the kiln was at 100*F. I then opened up two 5/16" holes drilled in the collector box and found it did not change the behavior described above. I drilled a third 5/16" hole. No change. Tried plugging the collector box holes with my fingers - no change. If I moved the burning part of the incense into the firebrick area of the hole, the smoke would escape the kiln. Later on, when the kiln was at 670*F I tested again with an incense stick and only the top plug removed. This time, no smoke stayed in the hole whether the collector box holes were plugged or not. There was a smell I'd associate with firing ceramics in the room. I'm fairly certain at this point, I need a better fan motor setup. More researching...

If using a lighter up against the vent hole isn't a good test, what is? Smoke against the lid cracked open with a dime? I guess I just don't know how people accurately test their vent systems except for with their noses lol.

The room isn't super air-tight. There is a bit of rust that's formed on the underside of the lid handle along with the discoloration around the metal band of the lid. I guess I was just expecting the downdraft would be providing adequate ventilation.

I built a box out of galvanized sheet - pretty stout sheet. The box is screwed into the kiln stand and everything is sealed with metal HVAC tape and attached a 4" metal flex hose. All the piping is taped. I did drill a hole in the box for testing, but taped it back up figuring it would draw the most air from the kiln with no holes/openings. The fan motor is installed a good 20 linear feet away from the collector box and in the cooler part of the garage, so by the time the air reaches the fan, it shouldn't be too hot. If I allow some external air into the collector box via some hole(s), will it draw more from inside the kiln? I was thinking it'd be the other way around. Maybe having smelly fumes in the room is normal - I don't know.

Hi folks, First time posting. I'm pretty new to ceramics but my wife has been doing it for a few years now. We built a tiny studio in a 12x12 room in our garage. In it, we have a tiny L&L E18S-3 kiln we bought from L&L new. I built a vent system collection box and piped it outside of our garage. It's 4" metal pipe, 3 90 bends on the suction end, total run length is about 25 or 30 feet. The fan is located in another part of the garage in my attempt to minimize any chances of fumes leaking into the room via the positive pressure end of the fan. This is the fan I used: https://www.amazon.com/Hydro-Crunch-Inline-Booster-Grounded/dp/B072N332WT/ Problem is, there are lots of fumes in the room (esp. early into the firing) and some corrosion/discoloration around the lid began shortly after we started using it. When the fan is running, I tried holding a lighter up to the single 1/4" hole we drilled in the center of the floor of the kiln and it gently pulls the flame down into the hole. I have a video of this in my review of the fan on the page I mentioned above. I feel no movement of air coming out the exhaust end of the pipe. We tried the smoke test around the lid of the kiln - nothing was being drawn in around the lid (with the peep holes pluged). I did not cut any bypass holes/slots into the collector box. I installed a room vent and it helps, but I wasn't expecting as much fumes as we are. Do I need to install a beefier vent fan? Everywhere, I read about CFM and various tests, but nobody mentions static pressure. I'm thinking I need to make a manometer to get this sorted out right. I know the motor should be outside the vent, but an inline duct fan was easier to install. Help!