Hi Chaps
I was investigating our kitchen extractor fan the other day and there is
a gap between the 4" circular ducting plastic and the top of the
extractor fan unit of about 4 ins (approx 100mm) which at present is
taped up using gaffer tape. This isn't much use at keeping grease out of
the cupboard over a long period (a couple of years in this case)

I'm guessing that during the initial fit the 90 deg angle rectangular to
round plastic fitting wouldn't fit into the cupboard from the top which
is why it has been cut off short.

My question is is there something like heat shrink sleeving at 4 or 5 in
diameter which could be used to successfully join the two bits of
ducting from the top of the extractor to the plastic ducting leading
outside rather than just gaffer tape which doesn't stick very well due
to everything being a bit greasy.

Any ideas where I might source this from?

Flexible plastic or rubber hose making a tight fit might also be acceptable.

dedics