To be brutally honest I would just turf it out and replace it with another. As AVB has so wisely suggested you are playing with an explosive liquid and it's just not worth the risk factor. If it was the last one on the planet then there would be some options to explore, ...................but a Briggs tank ?, they are as common as muck and as such simply replace it.

Very good advice from AVB.

Cheers,
BB.

I live a 24 Hour lifestyle, but every now and again I seem to fall asleep, well at least that's what my wife tells me.