Cone 6 glaze firing schedule and temperature

A cone 6 glaze firing peaks at about 2232 F (1222 C) when the last 180 F climbs at Orton's standard 108 F per hour. The medium program the builder writes gets there in five ramps and a 10 minute hold, 8 hours 13 minutes after you press start.

Updated November 3, 2026 · Source: Digitalfire PLC6DS cone 6 schedule

What is a good cone 6 glaze firing schedule?

Start with a medium program. Climb to 250 F to dry the glaze, run fast to 1000 F, ease past quartz inversion, climb steadily to about 250 F below peak, then finish at 120 F per hour to 2232 F and hold 10 minutes. Here's that program as the firing schedule builder writes it for cone 6, glaze, medium speed.

The elapsed times assume a 75 F start and an empty kiln. A full load or tired elements will stretch them. Tony Hansen warns on Digitalfire that a kiln may not be able to hold a fast rate high in the firing. When it falls behind, the firing runs long and the cone gets more heat-work than the program suggests.

The shape comes from the factory cone-fire programs built into Bartlett controllers. Bartlett's slow cone 6 glaze program, which Digitalfire lists as BRTS6, has three ramps: 150 F per hour to 250 F, 400 to 1982 F, and 120 to 2232 F, with no hold, done in 7 hours 34 minutes. The builder adds the gentler step from 1000 to 1150 F and the 10 minute hold at the top.

What temperature is cone 6?

Cone 6 is about 2232 F (1222 C) on Orton's chart, for a self-supporting cone heated at 108 F per hour over the last 180 F. Most controllers and glaze labels use that number. A cone measures heat-work, though, which is temperature and time together, so cone 6 bends anywhere from 2165 to 2269 F depending on how fast you finish.

The builder reads its peak from this chart. Slow and medium finish at 80 and 120 F per hour, nearest Orton's 108 column, so both stop at 2232 F. Fast finishes at 200 F per hour, closer to 270, so it climbs to 2269 F for the same cone. The full table, cone 022 to cone 10, is on the Orton cone chart.

Orton also notes that a cone takes 15 to 25 minutes to bend once it starts moving. At 120 F per hour, the kiln climbs another 30 to 50 degrees while the cone goes over. That's why the last ramp is the slow one.

When the controller and the cone disagree

Believe the cone. Hansen writes that most kilns reach cone 6 at about 2200 F, not 2232. His own Plainsman cone 6 schedules stop at 2200 F with a 10 minute hold, and he tunes that last step until the tip of a self-supporting cone 6 sits level with the top of its base. That's the bend Orton's temperatures are measured at. Orton adds that a cone touching the shelf and one at 4 o'clock differ by only 1 or 2 degrees.

If your cone 6 comes out short or bent too far, change one thing at a time. The builder's printed notes say to move the final hold up or down in 5 minute steps. Many controllers also have a cone offset, which shifts the peak for one cone only, and a thermocouple offset, which shifts every temperature the kiln reads. If only your cone 6 firings are off, use the cone offset and your bisque stays where it is. The guide to using witness cones covers where to set them and how to read the bend.

What does each segment of a cone 6 firing do?

Segment 1 dries the ware, segments 2 and 4 climb, segment 3 eases past quartz inversion, and segment 5 sets the heat-work that bends the cone.

Segment 1, to 250 F. Glaze goes on wet, and the bisque soaks up water from it. Hansen's Plainsman schedules climb at about 100 F per hour to 250 F and hold an hour there, because the next ramp is fast and the ware has to be dry first. He points out that 250 F is above boiling but won't crack the ware. The builder runs this segment at 200 F per hour with no hold. If you glazed that morning or the load is heavy, add an hour at 250 F the way Hansen does.

Segment 2, to 1000 F. The bisque firing already burned the organics out of the clay, so this is the quickest stretch, 400 F per hour on medium.

Segment 3, 1000 to 1150 F. The quartz in the body changes size at 1063 F (573 C), and the builder slows to 180 F per hour across it. Hansen's cone 6 schedules don't slow down here at all. They run straight through at 350 F per hour. On medium the slower step costs about 24 minutes. Keep it for thick pieces or a mix of thick and thin. For thin, even ware, it's the first segment you can speed up. Dave Finkelnburg, writing in Ceramics Monthly, puts the real quartz risk on the way down, when the ware is dense and cooling.

Segment 4, to 1982 F. The long haul, 2 hours 23 minutes on medium, while gas from breaking-down glaze and body materials is still bubbling out. Hansen's PLC6DS program offers an optional 30 minute soak at 2100 F so the clouds of tiny bubbles can merge and clear before the final push.

Segment 5, to 2232 F. The last 250 F at 120 F per hour. Orton measures its cones over the last 180 F, so this is the ramp that decides whether cone 6 bends. The 10 minute hold at the top lets the melt level out and gives the middle of the load time to catch up.

How long should you hold at the top of a cone 6 firing?

Ten minutes is a good start on medium. The builder holds 15 minutes on slow, 10 on medium, and 5 on fast. A hold adds heat-work, but slowly. Orton says a 1 to 2 hour soak near the cone's temperature is enough to bend the next cone up, so a 10 minute hold moves the result a fraction of a cone, not a whole one.

Kiln size changes the answer. Hansen uses 10 minutes in a small test kiln and says larger kilns need longer for the chamber to even out. Jonathan Kaplan, writing for Ceramic Arts Network, says a hold at the top helps a single-zone kiln even out from top to bottom, and that with multi-zone control a final soak isn't needed.

If the witness cone is already past level, shorten the hold before you touch the peak temperature.

Slow, medium, or fast: which cone 6 speed?

Use medium for most glazed ware. Mayco's directions for its stoneware glazes say exactly that: cone 6, 2232 F, medium speed, with a cone 6 witness cone. Go slow for thick pieces, packed kilns, and glazes that pinhole. Save fast for thin ware and glossy glazes you've already tested on the fast program.

Here's what the builder writes for each speed. Rates are in F per hour, targets in F.

Most of the difference sits in the last ramp. Slow spends about 3 hours 8 minutes on its final 250 F, medium 2 hours 5 minutes, and fast 1 hour 15 minutes. Hansen's notes on his own schedules point the same way: slow the final rise if the ware is thick or the kiln is packed.

Fast saves about 1 hour 50 minutes over medium. For comparison, Bartlett's factory fast glaze (BRTF6 on Digitalfire) skips the drying ramp, runs 570 F per hour to 1982 F, then 200 F per hour to 2232 F, and is done in 4 hours 35 minutes with no hold.

None of these times include cooling. Mayco says to leave the lid shut until the kiln is below 150 F, and room temperature is better.

How do you add a drop-and-hold to fix pinholes?

After the peak hold, let the kiln fall about 100 F as fast as it will, then hold 20 to 30 minutes. At peak, bubbles in a runny glaze can keep rising and freeze as blisters. A hundred degrees lower, the melt is thick enough to burst them and still fluid enough to close the craters. The builder adds this as segment 6.

The builder's version cools at 500 F (280 C) per hour to 2132 F (1167 C) and holds 20 minutes. That adds 32 minutes, so medium becomes 8 hours 45 minutes. Hansen's PLC6DS is the schedule it's modeled on. Here they are side by side.

Hansen adds two cautions. For glazes that are more fluid and reactive, drop further, perhaps 200 F. And don't go so low that the glaze starts to crystallize during the soak.

If pinholes keep coming back after a drop-and-hold, the gas is probably coming from the clay, not the glaze, and the fix moves back to the bisque. The guide to kiln firing problems walks through that case.

Should you slow cool a cone 6 glaze firing?

Only if you want the glaze to change. A free fall gives the glossiest surface. A controlled cool through about 1900 to 1400 F grows small crystals that turn many glazes satin or matte, above all glazes with iron, rutile, zinc, calcium, or magnesium.

Digitalfire's listing of the Mastering Cone 6 Glazes schedule (C6MSGL1) is one worked example. It peaks at 2192 F (1200 C) with a 15 minute hold, drops fast to 1832 F (1000 C), then cools at 126 F per hour to 1400 F. Hansen warns that slow cooling can shorten the life of an electric kiln's relays. The rates, the glazes that respond, and a full program are in the guide to slow cooling for glaze effects.

Should you fire to cone 5 or cone 6?

Fire to the cone your clay and glaze are rated for, and let a witness cone confirm it. Many mid-range glazes are sold as "cone 5/6", AMACO's Potter's Choice line among them. Cone 5 bends at 2167 F on Orton's 108 F column, 65 degrees below cone 6.

Published cone 6 programs don't agree on the top number either. Hansen stops at 2200 F with a 10 minute hold. The Mastering Cone 6 Glazes schedule, as Digitalfire lists it, peaks at 2192 F with a 15 minute hold. Kaplan goes the other way. He fires his cone 6 glazes to cone 7 for a better melt and more mixing between layered glazes.

All three are cone 6 firings in their own kilns. That's why a three-cone pack on the middle shelf tells you more than the controller can. Set cones 5, 6, and 7 together. A good cone 6 firing leaves cone 5 well down, cone 6 with its tip level with its base, and cone 7 still standing.

How should you load a kiln for a cone 6 glaze firing?

Glazed pieces can't touch each other, and no glaze can touch the shelf. Mayco's directions for its stoneware glazes give a short checklist:

• Fire on clean shelves coated with kiln wash. Kaplan calls kiln wash or stilts under the ware a necessity.
• Wipe the glaze off the foot and the bottom edge with a damp sponge before loading.
• Set each piece with its whole base on one shelf, not hanging over the edge.
• Keep stoneware at least 2 inches from the elements, and turn handles away from them.
• Stand a cone 6 witness cone where you can see it through a peephole or find it after the firing.

A packed kiln heats and cools more slowly than a sparse one. Hansen slows the final rise or lengthens the hold for a dense load, so for your first full kiln, use the slow program or add 5 to 10 minutes to the hold and read the cones.

Build your cone 6 schedule

Pick cone 6 and glaze in the firing schedule builder, choose slow, medium, or fast, and switch between F and C. It writes all five segments with the peak read from Orton's chart at the right rate, adds the drop-and-hold if you tick it, and prints a sheet to tape to the kiln. It doesn't add a drying hold or a slow cool, so add those on your controller if your load needs them.

Sources

• Edward Orton Jr. Ceramic Foundation, Temperature Equivalent Chart for Orton Pyrometric Cones, cones 022 to 14, with its notes on cone bending and soaks (ortonceramic.com).
• Tony Hansen, Digitalfire firing schedules PLC6DS (Cone 6 Drop-and-Soak), C6DHSC (Plainsman Cone 6 Drop-and-Hold, Slow Cool), and C6PLST (Plainsman Cone 6 Electric Standard) (digitalfire.com).
• Digitalfire listings of the Bartlett factory programs BRTS6 (Slow Glaze Cone 6) and BRTF6 (Fast Glaze Cone 6), and of the Mastering Cone 6 Glazes schedule, C6MSGL1 (digitalfire.com).
• Jonathan Kaplan, Cone 6 Pottery Glazes and Firing Tips for Creating Exciting Surfaces in Electric Kilns, Ceramic Arts Network (ceramicartsnetwork.org).
• Mayco, stoneware firing and loading directions (maycocolors.com).
• Dave Finkelnburg, Bisque Firing 101, Ceramics Monthly (ceramicartsnetwork.org).