On Sat, 5 Jun 2021 18:12:50 +0100, Tim Lamb
wrote:

Anyone come across a source for a *leak proof* bulkhead fitting for
standard 68mm rainwater pipe?

I am fitting out and old galvanised tank for rainwater harvesting (first
job, glass fibre the inside to hide the rust) and want to arrange an
overflow using a diverter coupler which means the fill pipe will be
below water level before the overflow level is reached.

Water gathered from a 55' x 18' roof so I need the full 68mm size!

Failing finding anything suitable off the shelf and if you are
fibreglassing inside the tank anyway (and a good use for it btw g) I
might be tempted to fibreglass a suitable stub of 68mm pipe though at
the same time then you can be fairly sure it will be sealed.

I'd cut several 100 mm long strips of CSM about 20mm wide and with the
stub held securely in place, glass the strips round the pipe like 'L
brackets' and flower petals and do the same again, overlapping the
first layer and then a circular collar over that with the middle cut
like a star (out to the 68mm diameter) and then a band round the stub,
to just pin down any lose ends (woven roving / bandage better than CSM
for that last bit. I probably have some here you can have (stick in
the post etc)).

Cheers, T i m