Step 6: PAINT AND POLISH
I use a coat hanger wire to hang the body and neck from when I paint. It keeps the guitar from touching any thing and makes it easier to move from one place to another. I like to dedicate one place for painting and another for drying to avoid any free floating particales from landing on the wet paint. I use a shed for painting and hang the guitar to dry in my garage.
SPRAYING TECHNIQUE Spray the body holding the can 6 to 8 inches away, moving either up and down or right and left depending on how you have set the nozzel. Start spraying from 2 inches outside the body and finish the stoke the same way. Don't stop or start the spry right on the body because you will end up with an uneven build up or paint drips. It is also good to spray a light "tack" coat first and let that dry for 45 min before laying on the thicker coats. This lets the paint adhere to the body better. You can also mount the guitar body to a square wooden stick that will fit inside the neck pocket so you can hold the guitar flat while you paint the top of it. This lets the coats build up thick and even, but watch for drips on the side.
After you have good coverage, let it dry for a few days or until it has hardened up enough. Inspect the surface for and runs or imperfections. If there are any runs them you can wet sand them flat with 800 grit wet sand paper and a sanding block. Usualy you will be able to see if there is any grain showing that you might not have filled up when you preped the body. If there is them apply a few more coats to cover it up and wet sand it to make it level.
RACING STRIPES Once you have checked out the color coat and are satisfied with the results and have let it dry completely, you can move straight to clear coats or add some racing stripes... or any other design you feel comfortable painting on. I did a paint splatter on the guitar I'm currently working on and it looks awsome. Plus it was realy easy. I just sparyed some black laquer paint in a pan, dipped a brush in it and splattered it on to my liking. For racing stripes make sure you get auto masking tape so you don't get any bleed through when you paint. Decide where you want you lines to go and tape them off. Use a garbage bag to cover the rest of the guitar and make sure all the other areas of the body are covered and taped off to prevent any unwanted spray from getting on the guitar. Spray just enough coats of paint to cover up the base color. You don't want it to be too thick because you will lay daown a clear coat on top and wet sand to level out the finish. If it is too thick it will take much more coats of clear and more sanding than you will want to do just to level it out.
CLEAR COAT Stew Mac sells nitrocellulose lacquer that works realy well for guitar finishing but if your like me you can't afford $10 a can for paint. Or you can check out reranchthough I haven't used any of their products they are a little cheaper. I use Deft spary lacquer. You can get it at Wal-Mart for under $5 a can and it works great. Use the same basic steps that you used when you sprayed you color coats, keeping in mind that you want enough coats so you don't cut through the clear top coat when wet sand and polish it out. Now comes the waiting. The paint has to set for several days to a month to let the solvents that are in the paint to rise to the top and harden. The paint will feel dry but you will notice that it might feel a little sticky or soft when you touch it. I like to do a "nail" test on mine. I use my finger nail and push it into the painted area in the neck pocket to see if it is still soft. No one will see the inside of the neck pocket so it's ok if you scratch it. Once it has cured completly you shouldn't be able dent the finish. It could take longer than a month for certain finishes to harden completely but trust me, you will be glad that you waited. For more information about all the different types of lacquer or clear coats products that are out there and how to choose what may be right for you, check out the drum foundry they have some great info.
WET SANDING You can wet sand with 600 or 800 grit wet sanding papers that you can get from the hardware or auto body shop before you apply the clear coats. You can get precission paper from Stewart Mac Donald that are suppose to cut better, last longer and yeild a better result, but I have never tried them so that's up to you. When wet sanding there are a few things to keep in mind. First you will need to soak the paper overnight in water. You can add a little Murphy's Oil soap to it. It will act as a lubricant and help it cut better. You could even soak the paper in a solvent if you use a laquer finish but I use water because it cleans up easier and dosen't smell. Next be sure not to overly soak the areas that you have drilled holes in. If the water get in the wood it can cause a lift in the lacquer that could lead to cracks in the finish. This is why some people choose a solvent to sand with because it is more forgiving in that area. Start wet sanding with a 600 to 800 grit paper and gradually work your way up to a 2000 plus grit. If you use water you may experience a condition in you finger tips that comes with a prolonged exposure to it called "raisoning". Just let them dry out for a while and get back to work!
POLISHING Once you have completed the wet sanding you wil have a pretty smooth surface that is almost a dull shine. You can either hand polish the finish or use a polising attachment to buff it out. Stew Mac has a polishing pad that attaches to you drill. Or you can get 6" foam bonnets from an auto parts store that will fit over the sanding disk attachment you may already have. It is best not to use any thing made from cotton because it will cut through the finish. Stew Mac also has polishing compounds that you will use in order working you way down to the swirl remover. It's on the expensive side so I use McGuires polish that you can get from the auto shop. If you use a buffing attachment make sure that you uae a different attachment for each grade of polish. Don't use the same pad for each one. Also remember to wait 10 minutes after buffing before you wipe off the surface. The lacquer gets hot and soft after buffing so give it time to cool. You will have to hand polish the cutaways, don't attempt to use the buffer on the edges of the guitar or cutaways because you will burn though the finish.
I finished my last guitar in this pattern:
Wet Sand 800/1000/1500/2000 grit,
Buff Down using an orbital sander that had a "hook and loop" base or velcro that I had attached a polishing pad that Gator Grit makes and McGuiars step 1 cleaner polish
Hand Buff with McGuiars step 2 swirl remover
It took less time than previous finishes and looked awesome.
Once you have finished polishing, clean off the residue the polish left behind with a clean cloth ie: an old t-shirt, look closely to admire the shine and get that piece of broccoli out from between your teeth.
STAINED FINISHES Check out the master Dan Erlewine put a stained finish on a guitar with out the use of spray equipment or buffing arbor.