Best way to sharpen a Crash Rat?

[jma10780]

I have a well used Crash Rat that I need to touch up. The top and bottom edges of the axe are still sharp, but the middle of the blade is noticeably dull. I have a Lansky sharkening set from ages ago, but it's not easy to mount the Crash Rat.

Any suggestions?

 

[Maqua]

I think convexing the edge via the sandpaper/mousepad method would be good for it.

 

[clone7]

I suggest try some Diamond stones.