I have gate-type isolator valves either side of my circulating pump. These have recently started leaking slightly - not from the gland round the shaft, but from the point where the gate mechanism screws into the body. They have fibre washers which seem to have perished. Tightening helps a bit but there is still a slight drip . . drip.
I intend to replace the valves - probably with ball rather than gate types (any comments?). This will, of course, require the system to the partially drained - so I need to wait for a convenient time - and need a short-term solution.
In a recent post concerning a leaking joint on a radiator valve, someone suggested using a silicon sealant. However, all the tubes of sealant which I have got state that the surfaces must be clean and *dry*. There's no way I can make my surfaces dry - until I fix the leak!
Does anyone have any suggestions of anything I can put on a damp surface, which will still seal?
TIA, Roger