Swirl-painted guitars were popularised by guitarist Steve Vai, with his signature Ibanez Jem guitars. The swirl pattern remains popular among fans. The pattern can be achieved at home with professional-looking results, but it is a difficult paint job to master. There are no tricks, but simply trial and error to get a perfect swirl. Most of the attempts come from mixing the paint. Some paint colours need a medium to thin them and help them float.
Seal the bare wood guitar body and headstock with sanding sealer. Carefully sand it down to the wood with 220-grit sandpaper if the guitar has been painted. Allow the guitar to dry overnight. Gently sand the dry guitar with 220-grit sand paper.
Fill a large bucket with water. The bucket should be large enough to completely vertically submerge your guitar body.
Stir Borax into the water. Use approximately 1.5 tbsp of Borax per gallon of water. Mix until all Borax is dissolved.
Drip several drops of your first colour into the water. It should spread out across the surface of the water. If it sinks or clumps, scoop it out, and thin it with an oil-based thinning medium.
Repeat with the other colours of paint. Use a paintbrush, nail or screw to gently swirl the paint until the surface of the water looks like your desired swirl pattern.
Hold your guitar body by the area where the neck bolts on, and steadily and smoothly dip it into the bucket.
Blow on the water to make the paint dissipate from around your guitar body. Lift the body straight out of the water.
Prop the body carefully on its bottom, allowing both the front and back to dry without being distrubed. Allow to dry for 24 to 48 hours before applying several coats of clear coat finish.
Immediately after dipping the guitar body, repeat the process with the headstock.