I was thinking, jewellery. Or even making chain mail - easy child 2/difficult child 2 is into that. I used to make pendants out of a piece of copper sheet. Maltese cross, a surfboard shape, that sort of thing. You cut the metal with a saw (I used tin snips for the Maltese crosses) then you file the edges smooth. You can enamel them or solder/glue other metal onto it. I made a Maltese cross for my then boyfriend, I glued a second four-pointed star onto the middle (I got the pieces from the star from the pieces I cut off the square to make the Maltese cross - draw one and you'll see what I mean. Copper is a good metal to begin with, it teaches good skills, is soft enough to work and isn't too expensive if he wrecks his designs by lack of skill. I used to use 18 g copper wire to make chains, rings and bracelets, and 16-18 g sheet to make pendants. A plumber's supply place gave me copper scrap that I bought by weight.
Chain mail - you find a solid enough wire (we use a moderately light gauge of fencing wire, I can get the gauge off husband if you want) and wind it around a pipe of the right diameter, to make a tight, even coil. You then slide the coil off and cut it - either with a saw, or snips. Again, it helps if you file the cut edges to smooth them. You then link the circles to form the mail. You can adjust the pattern so you're not just making a flat sheet of mail, you're making a shaped garment (works like a knitting pattern) so you can make one of those helmet thingies, or a vest, or whatever. Single mail is best to begin with, it won't be so heavy to work or to wear. It also is useful in teaching medieval history and technology - you understand how the heirarchy of a knight's staff worked. The page would make the links and do the basic five ring link up, the squire would link the assemblies together and shape the piece and the knight would wear it. The page would repair it when it was damaged in battle. If the knight were killed, his squire inherited it all, along with the job.
Knitting chain mail is a real conversation starter and is nicely repetitive for those in our family with Obsessive Compulsive Disorder (OCD) as part of their constellation of symptoms. The sight of a slim, pretty young redhead dressed in Goth clothing, carrying a large knitting bag from which she produced pliers and chain mail, is one to turn heads.
There is info online as well.
Good luck.
Marg