***warning, really long post by a bass player and hot rodder extraordinaire who has been enjoying his gin. I'm very long winded, and this is about paint... prepare to be bored, you've been warned..***
Information may not be laid out in the most reader friendly format, I explain the differences in paint types in a few different areas. If this confuses you more than it does me... Welcome to my mind.
Don't strip the paint unless it's flaking off! The best surface is an already painted surface, *paint sticks to paint better than it does to wood.*
* Exclusion being non compatible paints, lacquer with enamel for example.
Most factory finishes are polyurethane or base-clear, also called two stage. Enamel is used as a single stage, with the clear and color mixed together. Poly clearcoats work with both enamel and lacquer based paints. Moving on.
Most importantly, no paint surface can ever be too clean.
First step before I start sanding, I clean the surface with a grey scotch-brite pad and powdered Ajax( yes dishwashing powder), it may say "with bleach" on the bottle but its safe. This removes dirt, oils, and other contaminates off the surface. Oils of any kind are the enemy of all paint. Also, never use a red shop rag on any of this. Chances are it has silicone and oils in the rag if it's been used, which again will cause the paint to not stick.
I use the blue scott shop towels to clean or dry off my surfaces. They leave very little lint and are pretty durable, as a painter and car guy I keep a good stock of them on hand at all times.
After the surface is cleaned and dry It's now a good time to check for imperfections such as deep scratches and chips, most can be sanded out with 400 or 600 wet.
*If you can get them out with some sanding, skip this next step.*
If its a pretty severe I use catalyzed spot putty, small tubes of it are pretty cheap, 10 bucks or less. Let it harden up and begin sanding, if you didn't glob it on there you could start with 320 dry,600, then 800( or a grey scotch brite) and be ready to do a final clean.
After the nicks and scratches are smoothed out, make sure the paint surface is uniform. Use a gray SB pad to make sure there are no glossy areas, this gives the paint a good surface to adhere to, smooth areas can cause the paint to lift. It's pretty much the industry standard to finish out with 800 or a gray pad, you shouldn't need more than 2 or 3 sheets for your guitar/bass body.
I like to use rubbing alcohol on a blue towel and get my hand oils (or other contaminates) off the surface. At this point I suggest using rubber gloves to handle it, if you weren't already. It keeps skin oil off the paint and keeps paint off the hands. Dampen one blue towel with alcohol, follow it with a dry one, don't let the alcohol "air dry", that just dries the contaminates back on the paint.
If you're doing this in a garage, sweep the floor before the final clean. This gives dust in the air time to settle, and takes the majority of the dust off the floor so you can't kick it or disturb it with your hose (assuming your using a paint gun).Wet the floor to keep whats left of the dust from getting disturbed by your movement.
I hang my projects from my ceiling with metal coat hangars, bendable, reusable, cheap. A simple nail or bike hook can be used on the ceiling, just make sure it's sturdy.
Last step before spraying is to use a tack cloth to gently wipe down the body, this gets little specks of dirt (which are always there, trust me) off the body.
As far as a recommendation on paint, there are a few routes you can go.
You can go rattle can black and use a corresponding rattle can clear. This is cheapest option, but it's also the least desirable IMO. These paints aren't as strong as factory finishes because they aren't catalyzed or "hardened" paint. Which means pressing too hard or too high of a buffing speed with a buffer and you'll rip the paint right off the body. While burning through the paint can happen with any paint type, it's much easier to happen to non-hardened clearcoat. Also it takes non-hardened clear longer to cure, which adds time on to the project. Most catalyzed clears can be sanded and buffed in 16 hours, non-cat could take days or over a week to cure.
The other option is using a spray gun and paint you need to play mad scientist with. This of course means having a gun and air supply.This is the far more costly way but it gives you better results. This also helps set you up for future projects, can't tell you how many father/son projects dad and I painted in the garage.
For small projects like this you can use those small gun kits at wal-mart or rural king and be just fine. I've gotten good results from any gun I've ever used, from a $700 Sata, to a $30 Central Pneumatic,to my $250 Matco, the gun is only as good as the person holding it. Grab an HVLP set, which is High Volume Low Pressure if you can, so much more user friendly and uses far less air pressure to function.
Read the instructions on assembling the gun and how to set it up, that helps a lot when you're starting out. I'd also consider getting a few practice runs at painting with a gun first, a big cardboard box would work well. Also check out how-to's on youtube for techniques, if you're more a visual, scatter brained learner like me this will help tremendously...... Oh look shiny
I drain my air compressors water trap before every project, and I also run an inline water trap, but with a project this small you can do without. Moisture wont have time to build up with no more air you'll be using.
The base coat you can use can be from 25 dollars a quart to a few hundred a quart. To make this inexpensive, I'd use the quart can of Dupli-color Paintshop black basecoat. It's about $27 a quart, and a quart will be plenty. I used it on my guitarist and drummers Honda street bikes, Lays out pretty nice actually. They say its pre-reduced, but I always thin it down to get it to lay out easier. They have the recommended reducer on the can.
As far as the D-C Paintshop clear, I've never used it for a few reasons. One, I always get clear coat by the gallon, and two I only use catalyzed clear coats. Paintshop is non-catalyzed, which is again not as durable as catalyzed. Most auto Parts stores have their own house brand of clear which can be purchased in quarts and sometimes pints. House brand should work fine for this. That will need the corresponding reducer and catalyst, which the store should know what ones are needed. About 90 bucks for all of that from O'reilly Auto.
Every product I've mentioned can all be found at your local auto parts, some of it will be off the shelf back in the back. You can buy sand paper and scotch brite by the sheet, which is usually cheaper than the assortment packs that are out on the shelf. Same with rolls of painters tape, the stuff in the isles are shorter lengths and are normally the same price as the bulk tape in the back, and its the same stuff. I can get you part numbers and even photos of the products if you're interested.
Hope this ridiculously long post helps and doesn't scare you from doing the project or any other for that matter. All the steps I listed are pretty simple, some of them I didn't use starting out and learned along the way, others were ingrained in my head by my dad and grandfather. That's the way I do all my projects and it's tried and true, whether you use them or not is your discretion. If you're not overloaded with info and have questions, feel free to ask.
Derock is off to sleep times.