Re: Cleaning/Polishing Portlights
I've come across this type of portlight before, and they were typically made from either aluminum or bronze. IMO, they look to be made of aluminum, and not stainless, but I could be wrong. How I/we suggest any cleaning or polishing of your portlights depends on the metal. You can test stainless vs. aluminum by using an abrasive grinding wheel on an inconspicuous spot on your portlight. If it throws out sparks, it's stainless. If not, it's aluminum. Below is a how-to video:
If your portlights are indeed stainless, you can polish them up by hand fairly decent with some of the commercial products already mentioned. On the nuclear side, they can be brought back to a chrome-like finish, but this is best done by a metal finishing shop using industrial equipment.
On the other hand, if your portlights turn out to be aluminum, they are more than likely to have an anodized finish applied to them, and if so, your options are very limited. The option that I took on my own worn and pitted aluminum portlights, was to have them powder coated in white with a marine, three stage powder coating. They turned out nicely, and the finish is about as durable as it gets.
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