Hi folks.. pretty new to knife building and am looking at a couple of finish options for my O1 tool steel knives... I tried a hot vinegar bath on one of my knives and had difficultly getting a good finish.. I left it in for around 10 mins and got a little pitting .. Do you folks have advice on how to do a proper hot vinegar finish on O1 (or maybe not use HOT vinegar) ? Further.. what do you folks think of a coffee finish, how does it compare to a vinegar finish and any advice on doing that kind of finish ?? Thanks in advance for you advice..