On 05/06/2021 18:12, 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!

Is the fibreglass tank circular or does it have a flat side?

Can you uses a access connector, with the 'plate' on the inside of the
tank. You would need to cut the access hatch plate to make a suitable hole.

I would have thought, with some silicone sealant, and using the plate
with longer screws, ideally stainless designed for constant immersion,
this would solve your need.

https://www.plasticdrainage.co.uk/ac...ipe-black.html

The access plate would make a handy template for making the holes.