A charter skipper friend of mine retired and moved, when we were clearing out his tackle store, we found a very very large ( small litter bin sized ) new spool of 25 lbs mono , it had been plastic bagged and stored in a bucket buried under old rags and a biscuit tin of sinkers . He remembered buying it some 30 years before for his reels , he had put it away safely then promptly couldnt find it .
It is like new, no damage or visible deterioration and has been tested against a bucket with 20 lbs of lead in it . It did not break and I saw no reason to try any more weight as that line strength is fine for my inshore boat fishing for smaller species , in fact I would happily use it over graunchy ground from the beach .
So now I have enough 25 lb mono to last me out if I store it carefully .
David