Colleges and universities interestingly enough have no formal standards for this and will ‘generally’ hire competent people from the field.
The shops teacher part irks me. I would likely switch to being a shops teacher (red seal machinist, working on getting a red seal millwright ticket too, have the time and signed book, just need to formalize it all), but the year without pay is a deal breaker for me considering I make as much as a top end teacher right now.
Plus starting I would be at the bottom of the scale and likely stay close to the bottom end because I don’t have a degree, and you need those to move up the pay scale.
My 12 years of job experience with a diploma and full apprenticeship isn’t worth anywhere near a fresh out of university teacher who just got a degree and went straight into teaching. Despite the fact I can walk out of there into a 50$+ a hour job without issue.
The difficulty in becoming a shops teacher now makes me question most that do, if you’re such a good tradesperson why take the paycut?