Multicore Solders do the system. It consists of miniature rods, which are actually electroplated pieces of solder. The holes are reamed out with a special, slightly larger drill, and the rods pushed in. The ends of the rod are riveted over with the special tools provided.

The rods are then soldered, and the ends of the elctroplate make the circuit. The solder inside the rod is then removed using desoldering braid.

It is suprisingly fast to make a decent job.

steve