On Sun, 29 Nov 2009 16:14:06 +0000 (GMT), Dave Plowman (News) wrote:

If you can do that why not just cut a slot and use a parallel
sided
(not wedge shaped) straight screwdriver after the soak with
PlusGas/Diesel? Gentle use of a powered impact driver might be
better
than a hand held tool. How much pressure can you apply to stop any
driver turning out without distorting the bit you want to keep?

That's how I broke them off flush in the first place. ;-)

Ah.

How thick is the surrounding sheet? Could you punch the remnant
through?

--
Cheers
Dave.