I decided to try 'DOT 3 Brake Fluid" to loosen the paint for stripping.... Yes, I said Brake Fluid :-) it's working beautifully, and is MUCH cheaper than commercial paint strippers. I wouldn;t try this on a wooden or fingerglass boat though.
It has no ill effect on the aluminum.
You just have to be patient. Brush the brake fluid on after sunset and when you get up in the morning VOILA!!! seriously wrinkled paint that's ready to be literally swept off the boat.