There is a big difference if factory painted VS alum colored. The Alum colored boats have a plastic film that prevents the paint from bonding--thus it flakes off. :pissed: (the film is to prevent oxidation-which leads to the break down of the alum, which leads to weak or holes in alum over time). So as mentioned try acetone if alum/plastic coated, or try Duosol which is what I used. - both are of the products VERY flamable - It is a major chore to remove the plastic film. I spent a whole day doing it 25+ years ago. Arghhh! Lots of paper towels and rags are needed.
As for the amount of paint, I do not agree at all that 1 qt will cover a 12' boat. It took 5 qts to do my 14' for 2 coats sprayed on. I'd say close to 4 qts. Buy an oil based Aluminum primer paint, tint it tan and apply before the regular paint to increase the bond (paint store has it). Parkers oil paint is decent and about $28 a gal. Cabelas has it it in the stores. If you want to get fancy with multicolors--parkers has a 6 or 8 packs of spray can paint you can paint over the base paint. Being this is oil paint - it'll take awhile for it to achieve full hardness-like 2 weeks with 70 degree temps. Meaning a 3 weeks summer project to do it right so no piant is peeling/flaking off.
If you want to do it on the cheap, forgo the prep and justspray paint it, but you'll be always touching up the paint. Go to Wally World and buy the Krylon Camo spray cans paint--about $2.50 a can, buy more than what you think you'll need (you can always return unused cans later). Even going the cheap method--it is good to powerwash it thouroughly and remove any motor oil from the boat (dawn dish washing liq).
The Audacity of Bull Crap.
"Typical: Gun-loving, bitter bible-thumping white person" Barack Obama.
Hey I resemble that comment!!! Those are FIGHTING WORDS!!!