On Wed, 01 Apr 2020 12:56:16 +0000, AnthonyL wrote:

I've got a piece of plastic through which I want to pass a 1/2" hose.

I want the seal between the hose and the plastic to be watertight but
not permanent, eg I don't want to use a glue.

The container through which the hose will go will be holding about 2" of
water and then will overflow, basically a bird bath with a fountain
through the middle. At the moment the water is seeping back through the
rough 1/2" hole and the hose.

My caulking compound, last used 3yrs ago is as solid as a rock. I don't
want to buy another tube just for a tiddly job, neither do I want to go
to the shops.

Ideas?

Use a thick walled rubber hose through a smaller hole.