Summary for spalted steel Discussion
spalted steel? The question came from a knife maker who etched an O1 tool steel blade in white vinegar for an hour, expecting a uniform gray finish, but instead got an unusual patterned etch that did not wash out after rinsing. He wondered whether the steel might actually be a powder metallurgy grade and whether the pattern reflected alloy distribution. The thread excerpt provided does not include any replies or a definitive metallurgical explanation, so no consensus answer can be summarized from the source. The only concrete point is the original poster’s observation: vinegar produced an unexpected, persistent pattern rather than the flat gray appearance he was trying to achieve. Because no answer text is shown, the page appears to be a question seeking expert interpretation rather than a resolved discussion.
November 19, 2013
Q. A knife maker I know of and talk with now and again recently had an odd pattern etch in a piece of O1 tool steel. I’m going to quote his post over on https://www.knifenetwork.com/
“I think someone may have had an experience like this before but I don’t think any definitive answer was offered and maybe there won’t be one now either but I thought you guys might like to see this. I have etched O1 blades many times before, usually in FeCl, to give them a nice gray appearance and a little rust resistance. This time I use white vinegar
⇦ in bulk on
or
Amazon [affil link] for a whole hour to see if the pattern would go away and get a flat gray but it didn’t happen. I did rinse the blade in water a couple of times. Anyway, if some of you with more metallurgical knowledge than I have would care to offer an opinion it could be educational for us all. I’m thinking maybe this O1 is a PM steel and we’re seeing the distribution of alloying elements …”
Now I’ve become very curious about what made this pattern come out in the etch and would like to be able to replicate it, failing that I’d like to just know what is going on here.
As a side note, I did check with the original poster to make sure it was kosher to re-post this question here since I figure you folks have a much larger knowledge base to work from.
Marc Banks
Curious party, blacksmith, busybody – Lenoir, North Carolina, USA