I did some testing recently and proved to myself that the best grip technique is at the bottom of the blocks. Try not to let your pressure point get above the level of the edge, where rod/bore clearances could allow the block to rotate over the fulcrum of the edge, thereby changing the angle substantially. I know this feels wrong to most of you, but listen….
I have converted all of my non-strop blocks to bushings, which have nearly zero play. A while back, I bought a replacement pair of 800/1000’s. As I broke them in, I found that there was no practical difference between my bushing-modified blocks and the unmodified blocks. The angles were perfect. For some time I was anguishing over all the effort I’d put into this affair and was almost convinced there was no appreciable difference. Then one day I was working on a particularly long blade, which led me to use longer strokes. Under the microscope, it was clear I was creating another facet. , I happened to be video taping that run and played it back that night on my desktop computer with earphones (so as not to wake up Mama). During the taping I had placed a remote microphone on the table next to the WEPS. On playback, I could hear loud clicks on both the down stroke and on the up stroke. Click-click. Click-click. Click-click. This doesn’t happen with my modified blocks – only with the new ones. The long stroke had led me to move my pressure point above the edge and the click I heard was the rod in the bore in the block as it slapped from tipped in to being tipped out. In the middle of the stroke, the blocks which changing angles by almost one degree.
I’m not trying to sell bushings or the idea of bushings, I’m trying to convince you into learning how to use your stones properly. Don’t let them rock as they pass over the edge. Most of the veterans here have developed their techniques well enough to produce mirror-quality bevels. But for those of us who are still on the learning curve, this is an important lesson.
If you’re thinking that you’d like it more if you kept your pressure point above the edge, please understand that when you approach the upper end of the rod, you have a large lever advantage and variability in pressure can change the angle slightly, not to mention pressure variability at the grind point. Applying pressure below the edge ensures a more constant pressure at the contact point because of the mechanical disadvantage.
.
