On Tue, 22 Nov 2005 07:42:03 +0000, David Hansen
wrote:

There are patent fittings to avoid this, but I suspect it would mean
dismantling the stack to insert one, which you may not want to do.

There is/was a sort of drilled rubber bung type affair for doing this.
Haven't seen them for a few years (but then again I haven't been
looking for them.)

sponix