Monday, August 13, 2012

Refinished Electric Guitars







Here are the three guitars I refinished for my musician son, Michael, who plays in two local bands. He gave them to me, at my request, for airbrush practice. They still had their former finishes and hardware when he handed them over. (Regretfully, I neglected to take "before" pictures of them.) After some foot-dragging and much research, I finally took the plunge.

The hardware removal was easy. But the removal of the finishes - sanding each body down to the wood, was HARD! And the hardest part to sand down, was the inside curve, top and bottom, of each horn (not sure if that's the right name, but you get the idea). After some swearing, hand cramps and some creative thinking, I discovered a 1"+ wide flap wheel on a drill did the best job of removing the original finishes and the paint. However, please note, that GREAT care must be taken not to gouge, or distort the beveled edge lines (where the sides meet the flat surfaces). For the flat surfaces, I used an orbital sander with 120 and 150 grit paper.

I learned a lot in this guitar experiment. My base coat on both the Purple Haze and Axis guitars, was acrylic white primer, brushed on because it was too thick for my airbrush. Although I did sand between each coat of base white, I found at the end, that each guitar needed more basecoats than I actually gave them. I did notice that around the corners / sides, the basecoat was always thin. More coats would have prevented this. But again, this was a learning experiment, so things were expected to go wrong. The guitar "The Truth" was airbrush basecoated in blue-black auto air paints. It went on well, but very thin. (I have recently obtained a different airbrush for lacquer and basecoat finishes.)

Here are the steps I followed:
1.  Remove hardware and mask off neck (where fretboard attaches) and all routed out areas. Painter's tape is advised; although masking tape works, it leaves a sticky residue if left for more than two weeks.

2.  Sand off all lacquer/acrylic finishes and paint, down to wood. Take care not to distort the edge lines (where the flat surfaces meet the edges) by over-sanding. Use progressively smaller grit sandpaper, as the wood becomes exposed. Use a flap wheel or a large dowel wrapped with appropriate grit sandpaper  in the top & bottom insides of each horn.

3.  Wipe down with damp cloth or tack cloth to remove sanding dust. Inspect for visible gouges; re-sand questionable areas with small grit paper to smooth out gouges or swirl marks. Inspect all edges for consistent line widths with no flat spots.

4.  Make a tracing of each guitar: outside edges and all holes and routed out areas on front, back and sides. Not all models have the same configuration, and design placement around these "holes" is imperative. Label front/back appropriately. I taped computer/copy paper together and outlined each guitar and its "holes."

5.  Using your tracing, plan your painting design. Keep in mind the placement of the pickguard and pick-ups when designing. You don't want to obscure main parts of the design with a pickup "hole." If your client is using a clear pickguard, no problem, but if they desire an opaque pickguard, you might need to paint this with your planned design also, as an unpainted, opaque pickguard will obliterate any design beneath it when it's secured to the guitar.

6.  Once your design is chosen, you will now need to decide on the basecoat color and whether to airbrush or brush it on. Personally, airbrushing the basecoat provides a smoother finish. The type of basecoat, acrylic or enamel, will depend on what types of paints you will be using for the design. Acrylics with acrylics, enamels with enamels. 

7.  Mask off areas, flats and sides, where neck attaches to body and all routed holes. Apply basecoat, in multiple coats, sand off uneven, checked areas and reapply more basecoat. When you are satisfied that the basecoat is even, then it is time to trace your design onto the body. (I airbrushed Createx Auto Air blue/black on the "The Truth is Out There" guitar, and brushed on a white acrylic "kilz" type primer on the other two guitars.)

8.  Using dark graphite paper (Saral) for light basecoats (or light graphite paper for dark basecoats), trace your design onto your guitar body. If you plan to airbrush your design, follow your normal masking and paint layering routine. If you plan to brush paint your design, follow your normal decorative art steps. Sand lightly between layers of multiple coats, to minimize brush stroke marks and high areas where masked off paint colors meet. For all three of these guitars, I used water based acrylic paints in a mix of airbrush and paintbrush techniques.

9.   Once you're satisfied that the graphic rendering meets your vision and expectations, and that the graphic surface is fairly smooth, you are ready for another difficult step:  Clear coat.  

Here are my recommendations for the "rattle can" products which worked best for me. But at the time, I did not have a dedicated HVLP airbrush for clearing anything. (I have since purchased an HVLP airbrush, as yet untried, which I will dedicate to basecoats and clear coats.) Krylon Triple Thick Glaze and DuPont Spray Lacquer. I tested a few products, and these gave the best results. Note: You will need to use a mask, goggles and well ventilated area for spraying. The fumes are nasty and the sticky haze spray will get on everything you don't have covered up.

The surface should be dust free, finger print and oil free. Wipe down with a tack rag, or a lint-free damp cloth. Let air dry for a few minutes. Check for and remove any sticky residue from the tack rag.

To lay down a fairly even clear coat, you will need to suspend the guitar on a swivel (so it can easily rotate), high enough so you can spray the bottom flat edge easily. I put two eye-bolts in the ceiling of my studio and hung coated wire from the eye hooks, onto which I hooked a fishing swivel and modified metal coat hanger. The "rounded" top of the coat hanger hung from the suspended ceiling wire and the bottom of the coat hanger was bent into an "L" and poked into one of the holes at the neck. (Note: make sure this "L" hanger is placed against the inside of the neck, where the fretboard will be attached.)

The "Purple Haze" guitar was cleared with Krylon Triple Thick Glaze. This product is true to its name: triple thick. I did learn, however, that this product needs 24 hours between coats, even though you can touch it after a few hours without leaving finger marks. What I discovered, was that if you don't wait the 24 hours, a new layer of clear will cause tiny bubbles to appear. These tiny bubbles are the gasses escaping from the earlier, uncured clear coat. No amount of sanding will remove them, so its best not to get them in the first place. So keep that in mind, as you will need to plan in the dry time to estimate completion date. The depth and gloss from this product, when done correctly, is AWESOME!

The "Axis" and "The Truth" guitars were cleared with DuPont Spray Lacquer. This product was fairly easy to use, but each coat is thin, unlike the above Krylon product, thus you should plan for a minimum of ten coats with a few hours of drying time (in low humidity) between each coat.

10. Wet Sanding: Each product needs to be lightly wet sanded with 1000 grit between coats. Take care on the edges not to sand through to the primer or through to the body wood. When you have achieved an acceptable depth to the clear coat, where the surface is evenly smooth, but not yet glossy, you are ready to wet sand. 

I used successively, 1000, 1500 and 2000 grit wet sanding paper purchased at an auto body store. I used wet sanding blocks and cylinder, purchased from the same auto body store. The cylinder was for the inside flat areas at the top and bottom horn; I wrapped the wet sanding paper around the cylinder. Do not use a power sander at this point. The technique of wet sanding is to create a thin paste which acts as a mild abrasive; too much paste creates too much abrasion and interferes with your attempts at an even finish. I kept dipping my paper into clean water and lightly hand sanding in orbital motions, feeling the surface for uneven/odd areas with my free hand. After each go, I wiped the guitar down with a damp rag and began again with the next higher grit paper. After the 2000 grit paper, I wiped the guitar down with a damp cloth. The gloss was struggling, appearing in some places but not good in others, so I then used an auto body Finishing Polish (do not use Rubbing Compound - way too abrasive at this point) and brought the gloss up to a fine, eye-blinding shine. It is important to follow the specific manufacturer's directions for the finishing polish. The one I used stated to "not let it dry" on the surface; they weren't kidding. I accidentally let an area dry and had to really put some elbow grease into it to remove the polish!

I am not a pro at this - just learning as I go and thought someone might find this info helpful. I'm sure there are probably easier but more expensive ways to complete this sort of project, but I used what I had access to. 

All in all, the ending results were not too bad, for a first try. Should I ever get another chance at refinishing electric guitar bodies, I will find the knowledge obtained from this experiment very useful.

Thanks for your interest! If you have any questions, email me at thewickedbrush@gmail.com