Kiln Temperature Test
Testing the actual temperature of your kiln is pretty important.
If we don’t know that the kiln is running accurate then we cannot know if we are annealing at the right temperature….!
Annealing at the right temperature insures that our art will not crack due to stress still being in the art after we have finished creating it.
Do keep in mind that if you move your kiln to a different outlet that the electrical outlet may change the temperature of your kiln. I have 6 kilns and do move them to different outlets and test them and find that there is a difference then adjust my numbers in my recipes to work for the kiln being used and the kiln location.
There are many ways to test the temperature of your kiln and I am sharing here what works for me.
Needed items:
- Candy thermomenter
- Kiln to be tested
- Cotton clothing
- Face shield if opening the lid to take the temp
- Welding Gloves or Ov Gloves or Heat Resistant Gloves that are rated to withstand 400 degrees F.
The kiln recipe is as follows:
Ramp 1 50 degrees F per hour to 400 degrees F then hold for 90 minutes.
When you are done testing turn the kiln off.
In 8.5 hours from when you turn the kiln be prepared/ready wearing the protective gloves and cotton clothing to place the tip of the candy thermometer in through the peep hole to take the temperature. I like to take the temp at least 3 times for accuracy.
If you do not have a peep hole then you will need to turn off the kiln and lift the lid and take the temperature by holding the thermometer with your gloves on and add a face shield to protect from heat as well and take the temp. You may need to turn the kiln back on, let the temp come back up to 400 and take the temp again. I like to take the temp at least 3 times for accuracy.
If the temperature is 400 degrees F then you are spot on.
If your temperature is higher or lower then math needs to happen so that you can adjust all of your fusing recipes.
If you need help with the math then reach out to me with the temperature that you have at the 8.5 or a bit later time of the heating test.
Do share with me if you are taking the temperature through more than one peep hole that may by higher or lower in position of the kiln. Side by side peep hole temperature information as well should be shared with me.
NOTE OF IMPORTANCE:
If you ramp up faster than 50 degrees F per hour then you will not obtain an accurate reading at the 400 degree point.
The Math information:
This is geared to accommodate numbers for Coe96.
If you are using Coe90 then do change this up to work with your integral numbers.
After testing the actual temperature of your kiln then it is time to do the Math so you can adjust all of your integral target temperatures.
Take 400 and divide it by the temperature number that you have.
This equation gives the ratio of difference of the target temp of 400 degrees and the actual temperature you have.
To insure that the difference is correct take your actual temperature number times the ratio of difference number. If the equation works out to be very close to your actual temperature then you can move forward with the rest of the Math.
Integral temperatures that we need to achieve are as follows and the Math that needs to be performed is here as well:
If your actual temp is Lower than 400 the math is as follows:
The bubble squeeze at 1000 degrees F.
- 1000 times your ratio of difference number = the true temperature that you need to program in
First anneal for Coe96 temperature is 950 degrees F.
- 950 times your ratio of difference number = the true temperature that you need to program in
Second anneal for Coe96 temperature is 800 degrees F.
- 800 times your ratio of difference number = the true temperature that you need to program in
Target Temperature for Coe96:
- Take your target temperature times your ratio of difference number = the true temperature that you need to program in
If your actual temp is higher than 400 the math is as follows:
The bubble squeeze at 1000 degrees F.
- 1000 divided by your ratio of difference number = the true temperature that you need to program in
First anneal for Coe96 temperature is 950 degrees F.
- 950 divided by your ratio of difference number = the true temperature that you need to program in
Second anneal for Coe96 temperature is 800 degrees F.
- 800 divided by your ratio of difference number = the true temperature that you need to program in
Target Temperature for Coe96:
- Take your target temperature divided by your ratio of difference number = the true temperature that you need to program in
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- Some are not sure what Target Temp / desired effect means so here is an easy explanation....
If you want to slump, tac fuse, dimensional fuse or full fuse then the top number that you use to achieve that desired effect is the Target Temp. That number will need to be adjusted to match up with your kilns actual temperature number.
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**Remember that if you move your kiln to a new plug in or move your kiln shelf up or down that the temperature most likely will change inside your kiln and that new Testing and Math will need to be performed.
Should you need help performing the Math please do reach out to me, I can help.
