Self repair works on-hit. Only when that item is struck in combat does it have a chance to repair. Body areas that don't take hits very often like neck and feet take a long time to repair, naturally. At SR 5 there's no rush, but if you're nervous and want to spped it up you could take off all gear except the pieces you wanted to repair and go to a Yew sheep pen, start a fight with 9 sheep and tab out of combat. All those sheepish hits will repair you up fast.
