Thread: I need advice on a crumbling edge.

A few days ago, a member send a Wade & Butcher "American Razor", for honing.
It arrived in a "dull as butterknife" state, with only a partial bevel. I have completed the bevel 3 times now. Each time I come close to completing it, the toe half of the very edge completely crumbles away. At first I thought it was caused by some corrosion at the edge. The blade is restored to a mirror finish, but there is a lot of corrosion pitting as evidence that the razor has been seriously rusted at one point in time.
I have removed the crumbles with a few careful breadknifing strokes, and started over 3 times already, spending my entire afternoon at it today.. For the 4th time, I'm once more at the verge of completing the bevel, but the first signs of disintegration are already showing again.
After further contemplation, my best hunch is that during restoration, part of the razor overheated and lost its temper?

I've asked the owner to provide me with any additional information about this razor.

I managed to shoot a picture of a chunk of the very edge, that's loosing integrity. If I perform 2 or 3 more laps, the chunk will be missing, leaving an indentation at the edge, that can be seen with the naked eye (just above the visual threshold). The entire toe half of the edge is full of those chips missing. The other half of the edge develops just fine and smoothly.

Anybody has any ideas?