No, he meant years to work it out as in it would take years to work it out without Scotty giving it to him in advance.
Scotty made it clear he needed something strong and only a certain thickness and that in the year they were in there was nothing that was strong enough without it being too thick.
Remember when Scotty and McCoy told that plexiglass guy what they needed the guy said they couldn't make plexiglass that strong so small which is precisely why Scotty gave him the information for transparent aluminium..
That's what I have a the beef with, he COULD have used a sheet of pure metal and it would have sufficed but he wanted it to be transparent which is why he had to invent Transparent Aluminium early.
If you're saying the tank they made in the BoP was made from transparent aluminum, you're wrong.
Scotty asked him how thick the existing plexiglas would need to be to hold back the water. The guy said how thick it would have to be, AND that they had it IN STOCK. That's the material they took back to the BoP and used to make the tank, NOT transparent aluminum.
Because it would take years to understand, they could not have manufactured transparent aluminum that quickly for Scotty to take and use.