Good luck with your upcoming surgery in January. As indicated in the replies, experiences afterwards vary.
I was told not to do much of anything (no lifting young grandchildren, shoveling snow, vacuuming (!)) for 4 to 6 weeks after surgery.
The surgery went very well and after the catheter was out I took another week off before I returned to my volunteer teaching duties which I do for three hours at a time, three times a week.
My biggest concern was incontinence - wetting in front of students. I work with small groups but embarrassment is embarrassment whether it be 5 or 30 students. The day I got the catheter out I was very concerned because I had little control. Things improved steadily after this. When I returned to teaching after 3 weeks I still used a pad just to be safe even though I was dripping just a bit.
As for lifting etc., I do not lift anything heavy, but I did lift my grandchild (30 lb) after 3 weeks with no problem.
I think another concern for you Tallguy will be tiredness. I taught for 40 years and I remember when I had hernia surgery twenty years ago (much younger then!!) and I returned after 4 weeks I thought I was back in tip top shape but after teaching for a full day I was very tired. I did continue to teach but made sure I adjusted my routine for a couple more months -- sitting much more often, making sure I took it easier in the evenings etc.
Your job with teaching and welding sounds demanding. You will appreciate having the couch nearby to have a rest.
Please keep us posted how the surgery goes and your recovery afterwards.