Yebligs wrote:

Best insurance seems to be in the sealing. I notice Set Square says 'most of
which (silicon) gets squeezed out', so I wonder if waterproof PVA wouldn't
do a better, and deeper, seal?

No, silicone is the thing to use here. The point is that as it gets
squeezed out, it fills any gaps between the two cut ends. The fact that
most of it gets squeezed out is a /good/ thing.

--
Grunff