Hot take: I thought fancy quenching oil was a gimmick until I ruined 3 blades in a row
I've been blacksmithing for about 4 years now, mostly using whatever old motor oil I could scrupe up from neighbor's garages. Figured it was fine, you know? Heat up, dunk it, good to go. But last month I was working on three chef's knives from 1084 steel, and every single one came out with micro-cracks after heat treat. Buddy of mine named Dave over at the local shop told me to try Parks 50 oil for $45 a gallon. I laughed it off at first, but after that third cracked blade I caved and ordered a jug. First knife I quenched in it came out perfect with no cracks and a clean martensite line. Has anyone else been stubborn about switching oils and regretted it?