Quote:
You could also use one hand to hold the tang and the other to support the opposite side of the blade with your fingers (or thumb) touching the steel where it is being abraded on the other side. If your fingers start to burn, take the blade away from the grinder. You'll never overheat the blade this way because your hand will burn at 200 degrees lower than it takes to harm the steel.
Again exactly what I was doing - fingers didn't burn but the metal still turned black... this is what surprised me. I did everything I could to prevent overheating and I though I was doing an alright job but a couple of spots just appeared to spontaneously flare and go black without feeling excessively hot to the touch.