Thread: Why lapping film rules

OK, so why is lapping film any better than a hone?

Flexibility.

Here is the edge coming off of the 0.3um aluminum oxide film, laid flat on the precision granite plate:



Not bad (I did not spend a whole lot of time on that edge...)


But then I put the magic of lapping film to work---I put a single sheet of plain paper under the lapping film, which adds some cushion, and give it a few passes....


Much better!

I've played around with mulitiple sheets under there, which leads to a stronger convexing of the edge, but a single sheet on the finishing grit seems to give the best results.

Viva la Film!