For those of you who have never cut metal (likely happens w/ wood also), tool chatter is a flexing and release of tension of a tool's cutting surface on the material to be cut. With power tools, the flex/release cycle usually grows more intense, leaving a rippled finished on the material cut. It's often a sign that too big a cut is being attempted w/ a light tool.

For those of you w/ course beards, doesn't this sound alot like a 5/8 full or extra hollow with the entire length of the blade engaged when it runs into a course section of stubble? The blade screams 'ALL STOP', and your adrenalin rightly convinces you that if you force it, you will be sporting another mouth.

This led me to the heavier grinds, which for me are much more forgiving. When possible, that's what you'd want when cutting metal also. More beef, less ability to make it flex or vibrate. It also will do greater damage if you get foolish, but generally it works. While I can plow on w/ a wedge or 1/4 hollow, it still acts like the heavy tool - fabulous for taking away the vast majority of the stubble, but at some point, you'll be touching up with finishing strokes that are using a small portion of the blade - a smaller, lighter cut. Just like finishing cuts on metal or wood.

So I learned to work w/ the small hollow and get the same result, but it took more time & care, mostly because the heavy stubble forces me to start taking the smaller cuts way earlier to avoid the flex & fear. To use the example above, the heavy stubble begins about 1" above jawline. The jawline is at an angle to a north/south cut. With the full hollow, I have to keep the edge fully horizontal or even angled further away from parallel to the jawline, so it never engages the entire blade length w/ the heavy cutting. The heavy grinds remain composed and I engage the full length of cutting edge by stroking parallel to the jawline & just run the whole blade length over the line and down the neck. All this does is complete a first pass in less time. XTG & ATG seem to take the same or similar amount of time with either a hollow or the heavy grind. Like metal or wood, the majority of the time is spent on the finishing cuts.

I know GSsixgunner has done more than a little time on a lathe (probably a vertical mill also), and probably many others. Do you guys think the wood/metal comparison is valid? Helpful? It helped me sort out why the heavy grinds were more comfortable and saved time. The noob that has heavy stubble is going to run into this condition. I'd like to make that obstacle easier for others.