|Perfect stance, working height and two hand grip|
Of course, it is dumb to think that both hands should be on the tool regardless of the way the tool is designed.. Having both hands on the tool, if it is intended for one hand use throws the human geometry off in relation to the tool and the work. If you are sawing a line, alignment of the movement of the arm in relation to the line of cut adds efficiency. If you throw another hand into the operation, the consequence can be binding in the cut, awkwardness and frustration.
Working height and the size of the tool also come into play. For instance, the author sent me a photo from his book, showing a boy of 8 or 9 hears old operating a saber saw with one hand. My own opinion is that a heavy tool like that, intended for one hand operation demands that the operator has sufficient strength in one hand to operate it safely. In some cases that is just not the case, and use of that tool may be premature, for two reasons, maturity and strength. I have had saber saws jump around in my own hands, and it takes some strength to keep one under continuous control.
|Black capped chickadee|
With first grade woodworkers, I ask that they start with two hands on the tool as they first learn, but then quickly transition to one hand behind the back as they gain in strength and control. Or not.
In the CSS classroom we use Vaughan and Bushnell Bear Saws. These work on the pull rather than push, and offer a large enough grip for both hands. I often find myself cutting with two hands when using this particular saw.
In my own shop, I am applying Danish oil to wooden boxes. At school, we are finishing model birds, and continuing to make legos™ in Sketchup.
Make, fix and create...