Temp paint or crayons

[ponderingturtle]

Would it make sense to buy say some 1450 degree temperature indicating paint or crayons to help in basic torch hardening of steels? I have not seen that recomended before using just magnets.

 

[ev13wt]

I've tried torch hardening but I always failed to get it evenly heated. I even used two torches. Problem was the open air environment, it would always cool too much at some point along the blade length.

How are you doing it to get it to heat evenly?

 

[ponderingturtle]

I am not yet, just thinking and planning. I just bought my first house and have other priorities but am thinking about things as they come to me. I was planning more on using a one brick forge or a coffee can forge, but I figured the liquid painted on the surface would give an indication on when it reached temperature and how evenly.

 

[Stacy E. Apelt - Bladesmith]

Temp-paints and similar indicators work best in an oven or in a muffle in a forge. If they are exposed directly to flames, the flame ( very hot) may change the mark long before the metal gets to the temp being indicated. Temple-stix are good for checking as you heat the metal. You just rub them on the metal. When it is at the right temp, you will see the color stripe , when it is lower, there will be no mark.

 

[ponderingturtle]

So crayons as a method of verification as they would not go into the heat but be rubbed on the metal makes more sense than paint. But it probably wouldn't give more information than a magnet. Though I suppose I could use one to check for being at say 1550, if it melts on the blade it is overheated. But it seems likely not worth it.

 

[Stacy E. Apelt - Bladesmith]

I didn't post the wording right, I edited it.