It appears, from photos, that you refer to a scrape or bare spot on the wire, not a damaged lamination. Laminations are thin steel plates stacked together to make the core. Coils of wire are wound or inserted onto or into slots in the laminated core. The coil wire is copper with a coating or film of insulating varnish or resin. A small bare spot like that on a single wire that does not come in contact with anything else is inconsequential although to be on the safe side, I'd recommend to repair by applying a drop or two of high temperature epoxy or 'super' glue.