I don't know any of this. I'm not familiar with the "rattle can" expression (english is not my first language), is it spray paint?
Oh, i'm sorry - yes, "rattle can" is a colloquialism for lacquer in a spray can. Sprayed-on hardware store lacquer (the "rust-oleum" brand comes to mind, but there are many options) can build a very attractive finish if the instrument is properly prepared and the finishing process is carried out well. Briefly, to follow one common finishing regimen, steps would be as follows for a conventional solid colour on the body only:
1: dissassemble the instrument completely, ensuring all hardware and electronics are removed from the body
2: mask off the holes for mounting the bridge, the control holes, and really, anywhere you don't want the paint to go
3: mount the body to a stick of some sort through the neck screw holes
4: sand the entire surface until it is very smooth with ~320 grit sandpaper (some have different opinions on grit choices) ensuring that you are following the grain of the wood, if it is a "bare" wood finish
5: wipe down the whole surface until it is clean, dry and dust-free
6: spray your first coat of coloured lacquer (hold the spray can about 12 inches from the surface and move smoothly)
7: wait about an hour or a little more then spray your second colour coat
8: wait another hour or so and spray your third coat of colour. Don't spray them too thick or they might get "drippy" looking and will be harder to sand later
9: let it all dry overnight
10: if everything looks well covered, you can go ahead and very lightly "scuff sand" the finish with dry ~400-600 grit sandpaper and clean it up, wipe it down, dry it off. If not, spray another coat or two (or three) following the "1 hour apart, up to three coats a day and dry overnight" schedule then move to "scuff sanding"
11: spray your clear coats following the same "1 hour apart, up to three coats a day and dry overnight" schedule until you get about 10 coats of clear, with the first few being pretty light. The last one should be allowed to dry for a few days.
12: polish with wet sandpaper starting with ~400 grit up to ~1000 grit (2000 or higher is better, but saving funds on wetsanding paper, you could likely get by with 1000) using something like a rubber eraser as a backer. Careful not to sand through on the edges!
13: hand-buff with some sort of buffing compound (a cheap one that can do reasonably well that i have tried is toothpaste) on a rag. This takes a bit of work and can be hard on the hands!
14: clean it up, wipe it down, reassemble, set up and rock out!
This is obviously a time-consuming process and can be a little trying on the patience. Patience really is the key to getting it to look good, but they can turn out very nicely if they are done well. Obviously this schedule that I have written out skips steps and is pretty sparse in its descriptions - if you'd like to try this, i really recommend reading up on it.
edit: and always try out a little practice run on some kind of scrap first!
