Tracking Mold Slumping Schedules

Posted on March 12, 2018

I just saw a post on Facebook asking how to keep track of firing information on molds, so I thought I’d share this simple tip.

After you’ve figured out the perfect schedule for a slumping mold, turn it over, and in silver sharpie write the thickness of the piece and the process slumping temperature. In other words, if the firing schedule looks something like this for a 9mm project:

300-1100-.15

600-1160-.20

9999-900-1.30

100-700-0

Use your silver sharpie to write 9mm-1160-.20

If you are firing a 6mm piece next time, the info will change:

350-1100-.10

600-1160-.30

9999-900-1.00

100-700-0

So write 6mm-1160-.30 over the 9mm entry

If you are using a casting mold, you will also want to write your fill weights.

This makes life so much easier. Just pick up your mold, turn it over and all your info is right at your fingertips.

I always used to use a pencil. Lead lasts a long time, but it does begin to fade after many firings and needs to be refreshed.

I ran a test using different pens and here's what I found:

I used these pens:

Ultra-Fine Tip Sharpie
Plain Ball-Point Pen
Fine Point Sharpie
Silver Sharpie
Blue Metallic Marker
Pen-Touch White Opaque Marker 2mm Point
Pilot Silver Marker
Pilot Gold Marker

Here's the mold before firing with each sample numbered:

And here it is after a normal firing:

You can see that both black sharpies (1, 3) and the ball-point pen (2) almost disappeared. The Metallic marker (5) smears a bit and faded to gray. The white marker (6) stayed very well, as did both Pilot Markers. The sparkle faded from the silver (7) and the gold (8) turned to a nice dark bold gray color. However, my favorite for affordability, accessibility, and staying power is the humble silver Sharpie.

So there you have it! Pencil works but fades away after several firings (you can see a few faded dates on this mold), so for permanence, use a metallic silver Sharpie to record your firing schedule on your molds. Now you'll never have to go rifling through mounds of paper to find your firing schedule again!