Users > Aqba > GlassBenchCalculator

This page describes how to gather data about how your glass bench temperature is controlled. (Each glass bench heats up and cools down slightly differently.)

Information to gather:

(see descriptions below)

• the heating values after adding 2 charcoal
• the heat jump when charcoal is added in multiple steps
• the amount the temperature decreases when no charcoal has been added for a while

Description of Data Gathering Process

"Ticks" and timing

In order to determine your bench's heating values, you will need to understand "ticks". A tick varies between 9 and 11 seconds. I usually take a watch that ticks loudly every second, hold it to my ear, and count 1,2,3,4,5,6,7,8,9,10 after adding cc and between each measurement. If the temperature changes after I reach 10, I start counting over at 1 just after the change.

Why are ticks important? Because many benches remain at the same temperature for several ticks at the end of their heating cycle. It's important to know how long it stays at the same temperature if you want to calculate the effects of adding charcoal multiple times.

Heating Values

• Let your bench reach 0 temperature
• Add 2 charcoal, and start counting seconds
• Write down the first temperature value (after one tick, approximately 10 seconds)
• Continue writing down a temperature after each tick (10 seconds). Write down a new value every tick even if the temperature hasn't changed
• You should end up with 10 values before the temperature drops (usually to 0)

Special Heat Jump

• Let your bench reach 0 temperature
• Add 2 charcoal
• Immediately after the temperature jumps once, add 2 more charcoal
• Write down each new temperature value until the heat spikes (usually to over 1000 degrees)

Once you have gathered this information, the bench's "special heat jump" is the highest temperature value minus the previous value.

For example, if my bench increases to 312 degrees, remains steady for a while, then jumps to 1094 degrees, my bench's "special heat jump" is 782 degrees.

Cooling Value

You can measure this step separately, or you can measure it after you've reached your peak value while doing the steps above for calculating the "special heat jump".

• Add charcoal until your bench has reached at least 500 degrees
• Write down the peak temperature
• Write down each new value as the temperature drops

The difference between each subsequent temperature is your cooling value. Ignore any temperature differences where the temperature drops to 0.

For example, if my temperature drops from 512 to 385 to 258 to 131 to 4 to 0, my bench's cooling value is 127.

Calculating Temperature Changes

Download a copy of the GlassBenchCalculator.xls spreadsheet (at the bottom of this page).

Enter the Heating Values, Cooling Value, and Special Heat Jump into the yellow boxes in the spreadsheet.

The spreadsheet tells you many charcoal to add after a temperature drop, if you want to keep a constant temperature.

It also shows you the temperature increases you get when you add charcoal multiple times (one tick apart). You can look at the boxed values to determine how many charcoal you need to add how many times in order to reach a specified temperature: for example, for reaching the melting or working temperature.

Comments? Questions? Requests?

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