Aluminum cleaning? in Antique and Classic Mack Trucks General Discussion Posted April 27, 2015 Put a good penetrating rubber protect product onto the rubber strips that are at the back of each shutter blade, before you do anything on the shutters - try using a good quality liquid type product and you can apply with an old tooth brush so you get into the groves where the rubbers are set. Let the product penetrate and dry before you polish the shutter blades, and try avoid the aluminum polish getting onto the rubber strips. And then after you finish polishing apply another coat of rubber protection product. Avoid any harsh chemical washing products on the rubbers.