I've got the boat out of the water now, and sitting up on pipe jacks ready to clean. I've purchased some aluminum cleaner (Aluma Bright by Bosh) which is basically an acid. I've never tried this method before, but hopefully it will be better than what I did last year. The recommendation on the bottle is to dilute 50% with water and spray on till wet. Then let set no more than 10 minutes and pressure wash off. I haven't tried it yet but it's supposed to foam up as in cleans the aluminum.
.
The Aluma bright should give you they results you are looking for. First wash it, to get dirt layer off.
One Tip - do not let it dry on the aluminum, do it in a cool shaded area. First thing in morning, before sun-up is good.
Keep it wet for up to 10 minutes and rinse.
The best way to apply, is with a cheap hand pump sprayer, keep walking around to make sure everywhere is treated.
