This is my new secondary. The coil form is a 33 inch (84cm) length of 6.25 inch (16cm) outside diameter green SDR-35 PVC sewer pipe. It is wound for 30 inches (76cm) with 22AWG (.644mm) green enameled magnet wire. In this photo it has just received a coat of clear gloss spray enamel.
It is still mounted on a primitive, but efficient winding jig. The axle is a 3/8 inch (9mm) x 36 inch (91cm) threaded rod through two Plexiglas end plugs. The axle is supported at each end by pre-punched angle iron brackets and has a small crank handle on one end. Everything is held together with elastic lock nuts to keep things from working loose during winding, and to provide a bit of friction to eliminate backlash--I can let go of the crank and walk away without fear of the wire springing loose. I didn't time myself, but I'm sure I wound this thing in less than an hour.
The Plexiglas end plugs are easy to make. I drew circles on the Plexiglas, slightly oversize, with a compass. I then cut them out with an electric jigsaw. Next, I drilled a hole through the center (which the compass stylus located perfectly) of each disk. I put a short bolt through the hole, chucked the disks into my drill, and spun them against a file to achieve near-perfect roundness and a tight fit in the PVC pipe ends. I didn't make the plugs just for winding--they will be cemented into the ends of the coil form and their center holes sealed with RTV.