crayons

S

sctt reynolds

Joined
Jun 29, 2008
Messages
25
I was just talking to a old toolmaker from 20 plus years ago he is going to teach me to heat treat my own knives . He mentioned that he used to use crayons to get the right temp he said you colour in the steel and the crayon would change colour when right temp .you use a differant colour for diff steel. my question is does any one know anything about this and were i can get some ? Iam in australia but would buy else were if thay had them thanks scott
 
There is such a thing as temperature sensitive "crayons" that do something similar to what you describe. A good indication of temperature in the absence of other means of measurement. You might try some internet searching to find them, or maybe someone here can help with a supplier.

--nathan
 
They're called tempil sticks. They don't change colors, but instead will melt at a specific temperature. There are a wide variety of different melting temperatures available. You can get them at Bearing Suppliers.
 
http://www.waltersandwalters.co.uk/html/tempilstiks.html

http://www.tempil.com/product_display.asp

welding suppliers may stock them in the higher heat ranges.

I have used them and they do work.
They helped me to somewhat learn to eyeball it. But i now use magnets.

I special ordered the temperature i wanted and they didn't last too long in my shop over the winter.
They absorbed moisture and turned to dust...it also rusted everything near it in the drawer.


how would a laser thermometer work
Click to expand...

you can search out past threads.
some people use them- but they are not calibrated to the emissivity of metals and there will be some error
damn convenient though. I have used them for a lot of other things.

thermocouples are better for forge and heat treat.
see http://www.omega.com
 
Last edited:
sctt reynolds said:
how would a laser thomomater work
Click to expand...

a high temp infra red thermometr works very well. I bought one off of e bay that measures to 2912 F. for less than $250.00. i can measure the forge temp or the steel temp or the steel temp while it is in the forge. only problem I have is when the color of the steel or forge is the same as the laser pointer's dot.
 
You must log in or register to reply here.
Back
Top