[SEL] O.T. O.T. O.T Restoring Antique Ice Box - help

[paulmaples at sbcglobal.net]

Hey gang my neighbor is restoring one of those old antique ice boxes where you put the block of ice in the top and the cold air circulates around the cabinet. The ice box is lined with thin layers of zinc metal. This zinc has an old cream colored looking chalk like substances all over it that she is trying to clean off. She has been sanding it but it is wearing her out.

Does anyone know of any product that would work to clean the yellow chalk like substances off of the inside of the zinc liners?

She wanted me to sandblast it but this is out of the question.

Thanks for the help.

Paul