One of the simplest crafts is the marshmallow shooter, a blow gun that ejects mini-marshmallows. You can let the children design the type of gun they want — the shooters can be as simple as one-pipe blow darts, or they can incorporate several pipes that are hooked together with elbow joints or just duct tape. Purchase pipes that are thinner in diameter to make it easier for the kids to blow out the marshmallows.
You can fashion a simple flute from PVC since the material is easy to drill and will not produce cracks. Let the children design the flute — research and discuss different types of flutes and pick one to copy — but ensure that you do the cutting and that you show them where and how to drill the finger holes. Cap the flute using a plumbing pipe end or leave both ends open. Make a lip plate by sliding a slightly larger ring of PVC over the mouth hole and drilling a hole in it that lines up with the mouth hole.
You can make jewelry such as bracelets, earrings or rings using PVC, but you will have to do the cutting with a hacksaw. A hacksaw cuts PVC easily but will leave rough edges, which you will have to sand down before the children can start decorating the jewelry. Use hot glue to attach ribbons, beads or other baubles. You can also paint the pieces using acrylic paints, nail polish, shoe polish and stamp ink, though you might get better results if you sand down the shiny top coating first.
PVC pipes can provide most of the parts for a Halloween skeleton: arms, legs, shoulders, ribs and spine. Your kids can start learning the major bones of the body as you instruct them on how to measure different lengths and widths of the PVC pipes for the various parts and then have them assemble the skeleton. The joints should be reinforced with hot glue to make the skeleton more stable. Use anything from papier-mâché to old milk jugs to create the parts you can't make with PVC pipes.