Saving a Rusty W/B

[duke762]

Picked up a fairly nice W/B Extra hollow ground. Not much wear but has some nasty rust on the edge itself. I wanted to sharpen it before I spent any time on a restore, to see if the rust had damaged the edge beyond repair. Ground through a lot of nasties and it looked like I had solid steel. After a full progression and test shave the edge had a couple of pretty bad crumbles when I was done.

Should I be able to see compromised steel under the scope when looking at the bevels? Doesn't it show up as discolored spots? I'd sure like to be able to find it during bevel set rather than test shave.

I'm positive there is good steel to be had here, I just haven't gotten to it yet.

 

[Legion]

Tape the spine and drill deeper. It is a safer bet with wedges and near wedges, but even with a hollow that is about all you can do.

 

[mycarver]

Legions right. Most any other blade you’d find solid steel as the bevel moves up.
But an extra hollow and ones with paper thin blade that have a lot of nasty rust , as you say, along the edge. They’re iffy at best sorry to say.
The depth of the pitting relative to the thickness of the blade is the reason. Pits from both sides keep appearing in the bevel as you try to set it.
Setting a bevel in pitted thin metal can be a tough call. If you try sanding out the pits you’re left with tin-foil for an edge.
I’ve seen more than I care to that looked reasonable till you check the edge. Looked like the profile of a mountain range from the old pits.

 

[Steve56]

It’s probably best to avoid full hollows with rust on the edges, as mentioned, all you can do is power through it and hope that tou don’t lose too much width.

 

[Gamma]

The weak steel is very hard to see sometimes, even with a very good optical system. I pick it up most easily in Dark Field viewing, but that's hard to explain. Usually, my magnification is on the lower end of the scale for greater DOF. I have a special fibre optic lighting system that helps.
Honestly - you can learn to feel it... takes time, but it's a better way than trying to see it. Good steel feels much different on the 1k... you just need the reference points which only come with doing it over and over.