black oxide finish

[daily_grind]

I etched a damascus blade for the first time with ferric chloride ... well ... I messed it up the first time (I was too aggressive with the sanding), so lets say second time. I noticed that the blade came out very black, which was sort of neat. I was wondering how durable the black was compared to a hot salt "blue"? Something like Brownell's Oxynate #7, for instance?

I'm guessing that the hot salt has a more durable finish - because otherwise why bother with the added risk of molten salt if ferric chloride is just as good.

 

[Stacy E. Apelt - Bladesmith]

It is just a surface oxide and will rub or sand off. Many folks do a coffee etch after the FC, but while shiny and black it isn't more permanent. Even the deeper treatments like Parkerizing and hot salts is only a surface treatment and will wear or sand off.