Recently my Stainless Steel swim ladder unfolded and lay for several weeks in the water. The bottom 2 rungs were covered in barnacle. I scraped them off, but still have circular deposits left.
I also noticed similar ones on my Bronze Prop and the SS Shaft.
i have tried green scrubbie pads & solvents etc. etc.
Any helpful hints how to polish then lil buggers off?
In general I just deal with the little bases left over when it comes to the hull as it doesn't really create fouling and will come off at a later haul out. On the prop and shaft I use a soft steel flathead screwdriver. I'm gentle; it's never scraped the metal that I've seen.