I wouldn’t volunteer for the mill work, but I’d definitely cross the line to do my normal job.
You’re not part of the union so your group of employees are not going on strike, correct?
So you not showing up to work on Monday wouldn’t be considered “striking”, it would be considered “Arithosa not showing up and then not calling in”.
I imagine if you do that a couple of days in a row you’ll find yourself out of a job and no one in management will know that you did it to support the union (because you’re not part of the union), they’ll just think you’re lazy.
For the record, I’m anti-union and it disgusts me that my co-workers have started one and I’m forced to pay dues.