john brook laid this down on his screen :
Someone I know puts a couple of very thin plastic sheets (cut up vegetable
bags from the supermarket)under the tin lids of tins of varnishes, paints and
glues that come stored in tins.

It makes the lids come on and off very easily and he claims they act like a
'washer' and hence give a more *airtight* seal. But since air passes through
plastic bags (why long life bread is packaged in 'silvered' plastic bags)
albeit slowly, would this be worth doing?

Once the lid is firmly back on, just turn it upside down. The what ever
it is inside will seal the gaps in the lid and prevent any more air
entering.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk