Very large copper range hood desparately needs to be restored (not cleaned in years) I tried tarnex and a brand X copper cleaner along with a lot of elbow grease neither working very well. Suggestions for cleaning and then protecting this large copper surface would be greatly appreciated. Thanks!

First you need to use a strong degreaser to remove the layers of gunk, then try the tarn-x. Brasso works well too.

Charles......good chance the hood was lacquered way back when ........so the first thing to do is to strip the unit with lacquer thinner....CAREFUL!!!.......This will remove the finish along with the grease/grime........Then when it's clean you can polish and finish to your delight.......