This is a tough one. I've been going thru this dilemma for years. My best and longest employed people have come from our local community college metals program. Almost all were still taking classes so could work only part time during the school year, but full time during the summer. I had a 9 yr and a 10.5 yr employee and both have moved on. Last yr, the 10.5 yr employee quit at the end of June and I was pretty much w/o help for the remainder of the yr. It made me feel my age and realize I couldn't go it alone with the volume of work I have.
Fortunately for me, a metal shop in the area closed and I was able to hire one of the employees. I was somewhat leery at first expecting bad habits etc, but the guy (45) has become a tremendous asset, and I don't have to start from ground zero.
So, that being said, keep an open mind and be positive.
John