Thread: Razor passes HHT before shave but not after.

I guess I should clarify a bit. It seemed that although the blade was sharp, the edge crumbled during the shave and I believe it was from oxidation right at the edge. After resetting the bevel, the edge at the bevel was 'shinier' and held a great edge after that. When it was first sharpened the edge had more of a satin finish to it.

Originally Posted by JoeSomebody

I guess I should clarify a bit. It seemed that although the blade was sharp, the edge crumbled during the shave and I believe it was from oxidation right at the edge. After resetting the bevel, the edge at the bevel was 'shinier' and held a great edge after that. When it was first sharpened the edge had more of a satin finish to it.

+1 on your statement. I have a nice razor that was NOS when I got it and the same thing happened

I don't know what would cause that, but lack of polish is usually caused by steel not being hard enough. That could occur if the blank was in the open air too long before it made its way to be quenched in an oil tank.

It would be unusual for anything else to cause a problem where the blade wouldn't take a polish unless it was actually pitted.

I have never hardened and tempered razors, so I don't know what kind of issues they have, etc, but most are ground with a bevel ground on them by machine, and any decarburized material would be removed by that grinding.

A number of things can cause chipping. First is cell rot, once a set of celluloid scales or a cell wedge begins to break down it will eat the steel between the scales beginning with the thinnest part, the edge. Fine rusting on the blade is also an indicator. If it is just the wedge, you will see damage and crumbling on the toe and edge, left unchecked it will spread.

Another common cause is honing with an aggressive low grit stone with excessive pressure. Low grit diamond plates and novice honers are notorious for this. A low grit will create deep stria, even once you polish the stria out the steel, it has a memory and the steel under the scratches can chip once thinned, sometimes you can get a few shaves out of the edge, but stropping will chip the edge.

I have noticed the same thing from newer hard steels, where I suspect the builders used low grit belt to shape the bevel. Usually after removing a bit of the edge with a couple of honings or lightly breadknifing the edge, to good steel it will hold an edge just fine.

With vintage razors, we know nothing of how they lived their lives in storage, often exposed to wild temperature swings from freezing to well over a hundred degrees.

Dear "Edgy" in Uruguay,

Stop using hydrochloric acid shaving cream.

Aunty Jimbo.