The result of a few layers was a pleasing improvement in performance. It is difficult to know the exact duty cycle of pump on to pump off, as it would have taken a fair time to record a few cycles. We had periods of 25 - 35 minutes with a pump on time of 55 seconds to re-evacuate. So, roughly 30:1. It was about 10:1 before.
There is the other joint at the right angle bend to have a go at. Both those have the M12, 3 point, bolt anchors fitted and suffer the highest mechanical stress.
The water at Bowbridge was just about to go over the spill weir. Yesterday it was some 150mm low. The streams are running slow at present.
There are still a few small bubbles exiting the outfall, but far less than first thing this morning.