I was hanging a ceiling fan in this room when I discovered that the mounting screw holes in the electrical box are stripped. My dad has suggested using JB Weld putty, letting it cure, drilling it out with a small bit and then using wood screws. First time homeowner and have neither the confidence nor the expertise to completely replace the box. Is my dad’s route the best course of action or is it a waste of time and/or dangerous to go that route?
Op, I'm an electrician. This comment is the best advice. All boxes used for fans need to be fan-rated. This is possible to do without attic access.
I haven't watched the video but this looks to be an okay start: https://youtu.be/DKWeyydoYTI
Just remember that ceiling fans are heavy and the little wiggle over time will cause more wear and tear than you might think.
Best of luck!