Hopefully Constructive: You can get a much more even spray job than that even with a can. YouTube and the web in general are littered with tutorials. Mostly it comes down to having enough distance from the target and going in smooth, even, side-to-side passes.
The idea is killer, though! Shiny polished aluminum showing through? Since you’re already spraying, I would consider a clear-coat step which will even everything out a little more and will preserve the aluminum’s shine.
It didn’t stick to the metal. Thats why the tips of the peaks aren’t pointy. If all the tape stayed firmly on the peaks wouldn’t have paint in them and they would be pointy.
First off forget the blue masking tape its crap. Get the regular old yellowish tape.
Make sure the metal is 100% clean and free of any oils, including fingerprints.
Once you begin to mask make sure you try and keep your fingers off the back of the tape. Once you get the tape down in whatever pattern you want take a nice clean cloth and rub the tape down to make sure its on good.
Do you airbrush? I’ve been meaning to send you a message because I too, dabble in the arts of yoyo painting! I’ve only used spray paint and it actually turns out pretty well! Here are some pictures of the stuff I’ve done! http://www.flickr.com/photos/71884271@N05/sets/72157630272579564/
The real key to airbrushing is the ability to make your finishes come out in different sheens. Masking and laying the paint is only the first step! If I could get an eggshell finish down I’d start dabbling on my own throws as its the only way to still have an all around performing yoyo that is painted.
As far as masking, there are many ways to go about it and many mediums to choose from as well. There are even liquid masks that can be applied and drawn on then cut out what you want to have exposed for the paint to adhere to.
Airbrushing will always allow the painter to perform the most detailed work in my opinion but then the finish texture comes back into play. And paint will always chip way more easily than ano or powder. Trade offs that one must decide about.