Pre-Firing Your New Kiln | Kilnforming

Pre-Firing Your New Kiln

 

Before using a new kiln for glass projects, you will need to pre-fire it. This burns out binders, moisture, and other residue left over from the manufacturing process.

New shelves can be slow to take on primer, so we recommend pre-firing them, too. To do this, coat your new kiln shelf with Bullseye Shelf Primer. (See Using Bullseye Shelf Primer for mixing instructions.) After the pre-firing, be sure to thoroughly scrape and re-prime the kiln shelf before firing any glass on it.

 

Pre-Firing Process

Place the primed shelf and kiln posts in the kiln and program it with the three-segment schedule below.

To allow moisture to escape during the first segment, vent the kiln until it reaches 700˚F (an opening 3 mm wide is plenty). Once the kiln reaches 700˚, close the kiln.

The top temperature (in Segment 2) is 1520˚F or at least 20˚F higher than the top process temperature you’ll be using for glass projects.

Note that curing paint or oil on the kiln’s elements can produce an odor. This is usually gone after a few firings but you may want extra ventilation at first.

See the Paragon User Manual for more info on safely setting up and operating your kiln.

 

Pre-Firing Schedule

Segment Rate Temperature Hold
1 400°F / hour 1250°F 1:00
2 AFAP 1520°F (or at least 20˚F higher
than intended top process temp
for glass projects)
1:00
3 400°F / hour 70°F (room temperature) ---

 

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Pre-Firing Your New Kiln