December 20, 2020

First test firing of the small Cress E1814 kiln. 

Contents: Loaded with some randomly glazed items – living life on the wild side.

8:15 AM: Started Kiln. Temperature 45° F.  Set to a MED/SLOW Glaze Fire to Cone 6 with a 5 minute hold.  Nothing special – pre-programmed options.  One thing to note is the display says Cone 6 is going to 2200…I am assuming they know what they are doing and that is based on rate not just temperature (2232).

***Segment 1***

8:20 AM: Temp 79° F. Went inside.

9:15 AM: Temp 456° F. Is that too fast? Checking Manual…

Per Manual, MED/SLOW Glaze ramps:

Segment 1: 400° F/hr to 1000° F

Segment 2: 100° F/hr to 1100° F (Quartz Inversion occurs at 1063°) 

Segment 3: 400° F/hr to 1950° F

Segment 4: 108° F/hr to set-point – 2200° (5 min hold added)

That checks out.

Smell of chemicals in air.  Ventilation may be needed – originally thought that the drafty garage was adequate, but definitely would not want to work in there during this time… 

***Organics should be burned out by 600° F.*** 

10:15 AM:  Temp 857° F. Spot on track. Smell dissipating. 143° until Segment 2 (starts at 1000° F)

11:15 AM: Temp 1064° F. QUARTZ INVERSION!!!

***Segment 2 should last until about 11:37 AM.*** 

11:44 AM: Temp 1146° F.  Still spot on target & temp.

***Speed is back up with Segment 3 (400° F/hr).***

12:55 PM: 1630° F.

***1652° F = Inorganic Material burning out of clay!***

1:40 PM: 1921° F. Segment 4 starts at 1950…checking again in 5 minutes 🙂

1:45 PM:  1958° F!

***Segment 4 – slowing down to 108° F/hr.***

• • START CHECKING CONES
    • • Cone 5 – 2163
    • • Cone 6 – 2226
    • • Cone 7 – 2259
    • Couldn’t make out bottom cones…top cones all upright…not sure on the bottom 🙁

2:45 PM: 2058°

• • • CONES: No movement.

3:40 PM: 2163°

• • • CONES: Cone 5 starting to bend.

4:02 PM: 2202

• • • CONES: Everything looks over, including 7…ughhhhh…

***5-Minute Hold***

4: 18 PM: Finished 5-minute hold with a final temp: 2210° F. Kiln Shutoff.

https://www.timeanddate.com/date/timeduration.html

Total Firing Time: 8 hours 3 minutes (even 8 according to kiln).

4:21 PM – Left kiln to cool – already at 2117° F.

Will check back early tomorrow morning to see what the temp is sitting at – should be around 18 hours post firing…might be able to open it??  To be safe, I plan to wait till 125 F – and if not there yet in the morning I will take out the plugs probably 🙂

POST FIRING NOTES: If I hit cone 7 on my witness cones, I for sure don’t need that 5 minute hold.  It might be better to adjust the firing with an offset to account for this.