Just to add to the OP question, I have refinished a Squire P bass recently and I used a belt sander to remove the existing finish, but not all of it. In places it was back to the timber but most of it was taken back to the paint/primer coats. I used Automotive rattle cans from Halfords to apply the primer, top coat and lacquer and I got a reasonably good result. I think the trick is to build up the coats without rushing and allowing sufficient drying time before applying the next coat. I used lots of thin coats and flattened off with 1000 grit paper between all coats.. It took me approx 2 weeks to paint my guitar, and then another 3-4 weeks for the Lacquer to harden properly. I have used the bass quite a lot since I finished it (gigs and Practice) and it is wearing well.
More details of my build here
[url="http://jasebass.webs.com/jasebass-002-bass-guitar"]http://jasebass.webs.com/jasebass-002-bass-guitar[/url]
Jas