Polyurethane varnish storing

[threedee]

Some 5 years ago i bought a tin of Ronseal DiamondHard floor varnish.
Had it opened once, didnt quite seal well afterwards.
Today i pull it off the shelf to see if its gone but its still liquid as it was before.
Made a sample dip a piece of wood, now drying.
So, original tin is rusty and doesnt seal. How can i save it and store ? Can i just pour it into any clear plastic container like a coke bottle to seal it ? Or will it eat plastic ?
Varnish is water based.

 

[OliverCarter]

I would imagine it wouldn't do a plastic bottle any harm, it's a water based varnish. You could also use a glass jar, once used for jam, juice or sauce. You could probably even buy a clean, empty paint tin from a hardware store or online.

 

[foxhole]

I store mine in old plastic jars , [ex fruit containers.]