I refinished a cast aluminum mororcycle rear wheel using just rattlecan car paint, (most likely "Duplicolor") many years ago I was too poor then to afford having it repainted after a mechanic beat up the finish changing my tire, so I decided to go the rattlecan way, knowing that I had to be diligent in trying to acheive the best and most durable finish as the rear end of a motorcycle presents some of the harshest road envoriments on a vehicle. Made sure the original finish is nicely scuffed up with sandpaper all over and totally clean from oil and dirt (before first sanding so you do not work any dirt and oil into the existing finish). Did like seven or eightcoats of rattle can color finish, sanding between all coats making sure the layers are cured enough befor hitting it with the next coat ( I used halogen spot lights we had in the shop at work to cure the paint layers overnight.) sanded the final coat and then hit it with three coats of rattle can clear to seal and protect the finsh also curing the paintwith the hot lights overnight. The results look even better than the orignal finish that was on the wheel albeit, my color shade calculation was just a tad off. The finish looked perfect and stood up to all sorts of harch conditions on the road after the additional 23,000 mile i rode the bike before I sold it in 1995. The rear wheel finish actually looked much better than the original finshed front when I sold it.
Yes, a very good durable finish can be acheived with rattle can paint. all it takes is proper preparation of the surfaces. a clean work environment, numerous light coats of paint instead of a few heavy ones, sanding between coats, a means of curing the paint with heat/light and a lot of patience. I wouldn't hesitate using the same basic procedures if I ever paint a bike frame one day. Only thing that might be different is the possibility of the presence of corrosion on the bike frame which will have t=o be dealt with an additional step, I suspect.

Chombi