My separatory funnel developed a crack in it. So i procured a wine jug to use insted. The only problem is that it has a metal lid. Would it be safe to use the wine jug even though lye and naptha will be coming in contact with the lid?

Do you know what kind of metal the cap is made out of?

Not too sure. It is a carlo rossie jug. I believe it has a paper and plastic insert to seal it.