I added a used shaper to my shop last month and I'm working it into my process with a small door job. It came with 3/4" thick solid aluminum fence plates the previous owner had made by a machine shop. These I like very much, but they are leaving stains on the hard maple I am presently using. Anyone have any tricks to seal raw aluminum to keep this from happening? I've used other aluminum fences that didn't do this but I believe they were anodized?