Newbie questionabout kiln setting notation

This forum is for questions from newcomers to kiln-forming.

Moderator: Tony Smith

Post Reply
Jon Markovic
Posts: 8
Joined: Sat Nov 13, 2021 2:57 pm

Newbie questionabout kiln setting notation

Post by Jon Markovic »

Hi,
My first kiln arrived today- am very excited and keen to get started.
Looking through the WG forums, I noticed a shorthand for kiln settings:

1-500°,1100°,10
2-250°,1300°, 5
3-300°,1425°, 5
4-full, 950°, 40

Am I right in understanding this notation to mean that
Stage 1 used a ramp speed of 500 degrees per hour to a temperature of 1100, then held at that temp for 5 mins, then
Stage 2 ramped at 250 degrees per hour up to 1300 degrees, then held for 5 mins, then
Stage 3 increased temp at 300 per hour up to the final temp of 1425, and held there for 5 mins.
Then I am guessing that "Full" means as fast as possible, so down to 950 and held there for 40 mins, and lastly allowing the kiln to cool naturally to ambient temp.

I am wondering why the increase in termperature to 1100, then 1300 then 1425 would have have been done in separate stages.
Perhaps to heat as fast as possible, without stressing glass so as to save time, and energy costs?
But could it have been equally safe to do it in one stage, i.e. to take the temp up to 1425 at the slowed rate i.e 250 degrees per hour?
Brad's book "Contemporary Warm Glass" seems to me to expain the heating phase (up top final max temperature) as being done in a single segment, but clearly there is a reason behind breaking it into smaller segments.

Also, just wanted to say thanks and great job on the book! I have found it to be really excellent- clearly written, and packed full of useful info, and will be an invaluable reference guide for well beyond my starter days!

Thanks
Jon
Don Burt
Posts: 573
Joined: Sun Mar 09, 2003 8:45 pm
Location: Cincinnati, Ohio
Contact:

Re: Newbie questionabout kiln setting notation

Post by Don Burt »

Your suspicions are well founded. I don't get that schedule's logic, but maybe someone can suggest a reason to consider that schedule. Graham Stone's 'Firing schedules for glass' is a cover to cover read recommendation. Some of your questions would be answered by chapter six where he lists 'Advantages of Reduced Speed' and 'Advantages of Maximum Speed'. His Glassworks in Asheville NC sells the book.
Post Reply