by Mike (toolman1)
(Winnipeg, Manitoba, Canada)
When I stop welding with 7018 rods a crater develops at the rod tip just as you've explained. To facilitate a smooth restarting I pinch the flux at the rod tip (while wearing your welding gloves!!) and it crumbles away enough of the flux to expose the metal rod, allowing for a smooth restarting of the weld. It does the same thing as scraping on a file but I find it's quicker and easier. It works especially well if you're on your back, up on scaffolding or a ladder.