hi dmc, by knife edge, I mean planing the boo down to a knife edge, ie. making it as thin as possible, so it literally makes a knife edge that is very sharp.It can easily slice your hand if your not careful . Remove the inner side of the boo til it meets the outer, hope thats clear?
Personally I never remove the rind or the nodes, I know that many do. but my theory is, if the boo has a natural protection why remove it, its good for the back to have protection!!! and I like the nodes, they look good .....take them down very minimally on a back otherwise its risky, and whats the harm in them ? the back just looks like natural boo.