Hello UG,

I have almost finished a guitar body i'm working on and I thought I'd share my experience with it. It's the fourth time I refinish a guitar. Two miserable failures, one moderate failure and now one that's really looking good.
I'm aware that I do not follow the guidelines of the Ultimate Refinishing thread correctly. I certainly do not question the correctness of that thread, but not everyone has a spray gun and access to all the specialised tools and paints. My way will not give you a professional finish but it is good enough to make your guitar decently looking.

My advice to anyone who is about to refinish a guitar:

Before you start, think about the following:
It's really NOT cheap. I spent about 50 euros on tools and paint. Keep in mind that your guitar will be out of order for at least two months (if you work quickly). Try it on a cheap guitar first, one with low resale value (my first attempt was on a USA strat, very bad idea!). It's a hell of a lot of work, you should only consider refinishing if you really hate the colour you guitar has now (mine was in the hideous fiesta red).
Make sure you got the right tools. Very fine sanding paper (up to p1200) is a necessity! Especially the sanding is really important! Don't spray on paint if it has just rained or if the air is really moist, it will make the lacquer very vulnerable.

Most tools and paint you need can be found at car accessories shops. There are internet shops that sells these items (sanding paper, polish, clear coat). But generally, it's (much!) cheaper in a car accessories shop.
DO NOT SKIP any of these steps. I did that the first time and it resulted in an enormous fail, messing up my USA strat (which i'm redoing now).
Nitrocellulose lacquer is the best lacquer for musical instruments. But since that is hard to get (and hideously expensive) where I live and I have not got a spray gun, I used acrylic paint, which seems to work fine.

Stripping the lacquer:
The ultimate refinishing thread has all the info on this. I urge you to use a chemical paint stripper, as it leaves the wood sealer intact. If you choose to sand your guitar you will most likely sand through the sealer.

Spraying the paint:
Sand the surface until it's nicely even. CLEAN YOUR WORKING AREA! Dust floating around will mess up the paint and cause severe frustration, which causes high blood pressure, which causes heart failures, which causes death! Attach your guitar body to a wooden beam, as if you were attaching the neck, so you have a handle. Avoid touching the fresh paint. Put the beam in a bench vice so the body is held horizontally (very important).
Spray the primer in several very thin layers (I sprayed about 5) with about 10 minutes between each layer. Don't spray more than 2 or 3 layers a day! Lightly sand with dry p400 sanding paper before you start spraying (obviously, don't sand wet paint).
The night before you start spraying the lacquer on, put some p400 en p800 sheets of sanding paper in a bowl with soap water. This will make your sanding paper last longer and reduce the chance of sanding through the primer. From now on, always do this with your sanding paper.
Sand the primer with p400 and with p800 until it's smooth.
Spray on some lacquer layers (I sprayed a whole 400ml can). 2 or 3 layers a day, 10 minutes interval. After another 5 layers, sand with wet p800 and p1200 sanding paper.
It is inevitable (at least for me) to completely avoid sanding through the lacquer. If you run out of spraypaint. You can buy some lacquer in a small bottle with a little brush (like corrector fluid) you can use for repairing the damage you did to the lacquer.
When you have finished spraying the lacquer on, let the guitar body rest for 3-4 days to let the lacquer dry some more. Sand again with (wet) p1200 sanding paper. Clean the body with a moist rag, to make it ready to polish it a first time. Polish it with a cotton polishing cloth and polish. I used "Commandant 4" which was available at a local car accessories shop. Rub on the polish firmly until everything is nice and shiny. Clean off the excess polish with a damp cloth.
Now you're ready to spray on the clear coat. Do this just like you did with the lacquer. But always use p800 and P1200 wet sanding paper. After the sanding, you polish it again. If you can find very fine sanding paper (p2000, it really feels like paper) you can use that after the polishing.
BE PATIENT! don't screw on all the hardware the moment the paint feels dry! Wait for at least three weeks!

I hope this helped you guys who are thinking of refinishing a guitar. If I knew all this the moment I started the first guitar refinish, I wouldn't have cocked it up 2 times.

Please share your refinishing tips 'n tricks!