One of the limitations you have when buying a guitar, especially a budget model, is the choice between the available colors. If you really want your guitar to have the color of your dreams, or if you just want to have fun modifying an old instrument, you can learn how to repaint it yourself. It is no longer difficult to finish any other wooden object (like furniture), but you need to be very careful to get a good result and a smooth surface, similar to that obtained in the factory.
Be prepared to take your time. Repainting and refining a guitar properly is a process that can take weeks of work. Don't be in a hurry. There may be a tendency to speed things up so you can play. The solution in this case would be to buy a finished product. If, on the other hand, you want to repaint it yourself, it will be necessary to proceed as it should - otherwise, the bad result will be visible once finished.
Steps
Part 1 of 3: Disassemble the Guitar
Step 1. Remove the strings
Cut the strings using the appropriate wire cutters. Unfortunately it is not possible to repaint a guitar without first removing all the strings and it is therefore likely that the truss rod will need some adjustment when it comes to reassembling the instrument.
Step 2. Remove the guitar neck
The screwed necks (called "bolt-on") are quite simple to remove: just unscrew the screws at the base of the joint behind the body of the guitar and remove them. Those glued on cannot be removed, but are often painted to match the rest of the instrument; you can then leave them and then repaint everything.
Step 3. Remove all guitar hardware
The jack output, pickups, bridge, knobs and pickguard can usually be removed with a screwdriver or Allen key. On some models, the output jack and knobs are connected to the pickups with cables that run through channels inside the guitar body and will therefore need to be unplugged to remove each piece individually. Make a note of the wiring diagram so that you can then reconnect the cables correctly at the end of the job.
Step 4. Remove the screws securing the bridge to the guitar body
Depending on the model, this step can be more or less difficult: in some cases the bridge is secured to the body of the guitar with real studs inserted into the wood. In this case, you can heat them with a soldering iron to make them expand: with cooling they will contract again and will be easier to remove. You can use pliers, but be careful not to bump and damage the wood.
Step 5. Set all hardware and fastening screws aside, and label each piece
The process of repainting the guitar can take a few weeks or even months, so make sure that every element, screw or bolt is well identified when it is time to put it aside, so as to avoid confusion when reassembling the guitar at the end of the job.
Part 2 of 3: Smoothing the Existing Surface with Sandpaper
Step 1. You have two options
The first is to completely remove the existing finish with sandpaper; the second is to notch it just enough to make the new layer of paint adhere. If you decide to use a semi-transparent stain, or if the original color is much darker than the color you want to give, you need to completely remove the existing finish. If, on the other hand, you want to use a solid paint, it is sufficient to rough the surface. Keep in mind that most luthiers agree that a thicker layer of paint significantly degrades the sonic characteristics of a guitar than a thinner layer of paint.
Step 2. Use an orbital sander to remove the "bulk" of the finish
Insert a coarse-grained abrasive disc on the sander and pass it over the entire body of the guitar making circular and regular movements. This should allow you to remove most of the lacquer and paint on the body of the guitar. Don't be tempted to use a paint remover: they are very toxic products and you will end up with a poor job, as the protective layer of polyurethane applied to the surface by modern guitar makers is too hard to be removed with a solvent..
Step 3. Use sandpaper or an abrasive sponge to remove the remaining coating
For curved parts that are difficult to reach with the orbital sander, use sandpaper wrapped around a wooden cylinder, or an abrasive sponge. Coarse sandpaper is best for removing paint and lacquer.
Step 4. Make the surface smooth and even
After you have removed most of the finish with the coarse sandpaper, you will need to smooth the surface well using increasingly fine-grained sandpaper. Pass it over the entire surface, first using a 120 grit and then a 200 grit (or similar) to complete this step.
Step 5. Remove sanding dust
A vacuum cleaner with a hose can allow you to remove most of it. You can complete the cleaning job with a can of compressed air, a damp rag, or a gauze cloth.
Step 6. Apply a wood primer
Unless you want to leave the wood uncoated to achieve a particular aesthetic effect (always valid when working with porous woods such as mahogany), you will need to fill the grain with a pore filler or wood filler. Choose a water-based or oil-based primer, with a color similar to that of the paint you are going to use for the paint job.
Step 7. At this point, use a solvent (alcohol, turpentine, naphtha or similar) to remove all excess oils
Do not touch the surface of the guitar body after this step to prevent oily substances on your fingertips from ruining the finish.
Part 3 of 3: Applying the New Finish
Step 1. Make sure you paint in a dust-free environment
There are tons of dust particles in the open air, even on a sunny day, that could ruin your work - including insects that will be attracted by the smell.
Step 2. If you decide to work indoors, be sure to wear a good quality air filter mask
Always wear safety glasses.
Step 3. Avoid painting in an area where paint particles you splash could ruin floors and furniture
The ideal would be to proceed in an environment such as a workshop, garage or something similar.
Step 4. Placing the guitar body in a large box resting on a movable counter (such as a TV cart) will greatly reduce spatter and protect other elements within the room
The opening of the box should be on one side, in order to hold the paint inside and to drag the guitar easily. Putting a layer of newspaper inside allows you to have a kind of paint surface that you can easily replace.
Step 5. Choose the paint or stain to use on your guitar
If you opt for a solid paint, use a strong one, such as polyurethane or nitrocellulose. Nitrocellulose is the best quality standard, and can be purchased at auto accessory stores or online, but it has a very long drying time. If you opt for a stain, use a water-based one and then apply a clear polyurethane or nitrocellulose-based finish, OR use an oil-based stain to combine with an oil-based paint (such as Tru-Oil wood). If you use the spray painting technique, you will avoid seeing the brush marks.
Step 6. Apply a few coats of primer
Use a primer suitable for your chosen paint. Aim to apply 2 or 3 thin layers rather than a single thicker layer to facilitate drying and avoid dripping.
Step 7. If you have opted for a solid, non-transparent color, apply the paint layers
Give it two layers, letting each of them dry for the time specified by the manufacturer. Finally, allow the paint to dry for a week before applying the clear topcoat.
Step 8. If you have opted for a stain, clean the surface with a cloth
First, lightly dampen the wood to make it easier to apply the stain and prevent staining. Apply the stain following the manufacturer's instructions, in as many layers as needed to achieve the desired aesthetic result.
Step 9. Add a clear coat on the guitar body
Again, the recommended material is nitrocellulose. Try to apply it in layers as thin as possible, until you create an effective protective surface layer. It may take up to twelve layers to achieve a finish similar to those obtained in the factory. Apply three coats at a time, letting a few hours pass between each and a week between groups of three. The first group of layers must be particularly thin; after that you can make them a little thicker, but don't be in a hurry.
Step 10. Wait
If you have chosen a nitrocellulose or polyurethane finish, let it harden for 3-4 weeks. If you choose an oil-based finish, such as Tru-Oil wood oil, just wait a few days.
Step 11. Polish the finish
Moisten the surface and smooth it using increasingly fine-grained sandpaper: start with a 400 grit and continue with a 600, 800, 1000, 1200, 1500 and finally 2000 grit. Don't skip any of these steps, so as to avoid that small holes, scratches or small wood curls remain on the surface which will then be impossible to remove. Be careful not to completely remove the clear protective layer until you get to the paint, especially on the edges of the guitar body, where this is thinnest (which is why there are so many layers of it). Stopping at this point will get a satin finish; for a "mirror" finish use a polishing disc and polishing paste, such as 3M "Finesse It" (available online). Alternatively you can use "Micro-Mesh" abrasive cloths or 1500, 1800, 2400, 3200, 3600, 4000, 6000, 8000, and 12,000 grit abrasive sponges - the latter can be a way to achieve a super finish. polishes without having to use a grinder, which can be expensive.
Step 12. Reassemble the guitar
Replace all hardware removed at the start of the job with the screws and any bolts. If you unplugged any leads when you took the guitar apart, reconnect them with a soldering iron. This is also the time to replace any low quality components (such as potentiometers) with better quality ones. You can also buy a new pickguard, or make one yourself. Once reassembled, the guitar can be cleaned and polished with the product you normally used. Now you just need to put the strings back and tune it, and you're ready to show off and play your great new instrument!
Advice
- If the neck is removable, you can attach a long piece of wood in its place so you can more easily handle the guitar while working without having to touch the fresh paint.
- Using a latex-based paint, washable with soap and water, will make it easier to keep the work area clean.
- For a very smooth finish, use a wood primer after scraping off the existing finish with sandpaper. The primer helps to fill the pores, makes the surface smoother and gives a better aesthetic appearance to both the paint and the clear lacquer.
- To customize the appearance of your guitar, you can apply water decals under the clear protective layer.
Warnings
- If you decide to use a solvent to remove existing paint, be very careful. Use a good quality paint respirator and do the job outdoors. Paint solvents are extremely toxic and carcinogenic.
- Always wear a face mask and safety glasses while using sandpaper and work in a well-ventilated area.
- If you decide to use the spray painting method, wear a protective mask (you can buy them from retailers - even online - of spray painting equipment).
