>>/957769/
Another way of telling if a blade has an edge: stand with some light source behind you (optimally a window) and look at the edge. If don't see the line between the two side of the edge, and you feel you are squinting then it should have a sharp edge.
> heated the handle to burn its way into the wood 
Would not have thought about that. Most likely won't try it.
> ruin your hardening
Yeah, slow cooling from high temp soften the steel.
> chainsaw file 
I don't have a chainsaw file. Maybe something similar.

 >>/957771/
/austradies/

 >>/957772/
 >>/957773/
It is.