Brother-in-law called. He broke a sparkplug off in his boat (marine 440) when he fogged it last fall. Pretty sure the porcelin is broken off flush with the head. What is the best way to get the porcelin out and has anyone had luck with easy-outs on broken plugs (I'm assuming being in a boat rust is an issue). I can use heat, but concerned with cracking the head and igniting the fogging oil (I'm sure it's a nice confined space ) What kind of tools should I bring since has has none and I'm an hour away?

You saying the hex broke off and left threads and some porcelin in the hole?

It will come out..,. The porcelain is above the shank and thread part..

I would use a tapered reamer first. NAPA $20. Just dribble some penetrant on the plug threads and gently back it out. And if that don't work, its easy-out time!