by The Saw Doctor
Have you ever experienced a Black eye? and I don’t mean the black eye that greets you at the front door when you get home late from a night out with the boys!
The black eye that the Saw Doctor is referring to appears on circular saws. You might be familiar with this and know it as a circular blue heat mark (oxidation) with burnt saw gum stuck to a lump on one side of the saw and the other side has the blue oxidation heat mark.
What’s caused this?
It’s caused by excessive heating up whilst sawing. It happens when the tooth edge starts losing its sharpness/has become blunt and you start pushing the saw harder to cut the timber, the tooth edge is then under pressure, therefore this causes the blade to flex and the constant rubbing of the body of the saw against the timber then becomes a friction spot and this is how the black eye is formed.
A black eye can also form from using a blade with too many teeth for the thickness of timber being sawn.