Late 70's & early 80's oil boom.
Some of the Ol' Hands that read the comments on here will remember after the Alaska pipe line boom there was the Wyo. oil boom in the late 70's into the early 80's.
Oil rigs all over the southwestern part of Wyoming and 2 new oil refineries being built on the mountains, one Amaco and one Chevron.
The only tig rigs I seen there whether on-site or on rig trucks was scratch start. They were the choice tool when making belt buckles, bracelets and thermos bottle handles. LOL
Return to Scratch Start Tig with a Twist.