Guitar Paint Guide – Nitro Spray Highlight Grain

Before Starting

• ✓Always be very careful with your body and your sleeves. It's easy to cause a bump, scratch, or drop of polish. Don't rush.
• ✓Make sure your environment is always clean. A common issue is applying stain or varnish in a dusty setting, which results in an imperfect finish.
• ✓Don't varnish the fingerboard unless you know this is your preference. Normally, we apply nothing or just a little lemon or mineral oil (for Rosewood or Ebony) to maintain a comfortable feel.

Useful Products Available on The Guitar Fabrik

Only the strictly necessary tools are listed here. However, you can always enhance your result using additional tools and adjustments. These require experience in lutherie and are not covered here.

Sand Paper	A range of sandpapers, P240, P400, P600, P800, P1000, & P1200, for sanding and polishing. Use them throughout the finishing process, especially for initial sanding and final polishing.
Copper Tape	Recommended: The adhesive copper tape will prevents electromagnetic interference from pickups and improves sound quality.
Sanding Block	Recommended: A 240-grit sanding block will be used in both during the early sanding and during the final polishing stages. Attach different grit papers to suit your different needs.
Gloves	A pair (or two) of rubber gloves to protect your hands during some finishing stages.
Painting Brush	Optional: A wide brush will make the applying of a grain fille, a dye or a varnish evenly, easier.
Cloth	Optional: It will be used for applying a dye, a Tru-Oil finish, a polishing product or to clean & wipe your guitar neck and body. A microfiber cloth is recommended.
Masking Tape	It will be used to protect areas like the fretboard or bindings that shouldn't be painted or sanded.
Plastic Card	Optional: Useful for smoothly and evenly applying th grain filler.
Vacuum or Air Spray	Optional: Useful during sanding to remove dust and keep the workspace clean.
Fan	Recommended: For dry sanding during the final polishing phase.

Glue Stain

Before starting the finish, take a close look at your guitar body. If you notice any glue stains, remove them gently by hand-sanding with P240 to P400 grit sandpaper. Sand gradually and evenly, checking your progress regularly — the goal is to eliminate the stains while removing as little wood as possible. Also take this time to inspect the entire surface for any dents, scratches, or rough areas. Smooth them out with light sanding if necessary, as these imperfections may become more visible once the finish is applied. Finally, make sure all the contours and edges of the body are clean and well-defined, especially around routed areas, cavities, or binding. A clean surface is essential for an even grain-raising step and a flawless final result.

Raising the Grain (optional)

This step is optional but recommended for mahogany or ash when using water-based products — especially with our translucent kits. It helps achieve a smoother finish and reduces paint consumption, particularly with nitrocellulose or opaque polyurethane finishes. Skipping it won't ruin your result, but it may slightly affect the final texture.

When water or water-based products contact bare wood, the fibers swell — this is called "grain raising". Once dry, the surface feels rough. Since this effect is unavoidable with water-based finishes, it's best to control it before applying your stain or sealer.

To do this, dampen the wood evenly with a sponge or cloth and let it dry completely (ideally overnight, or at least 4–5 hours in warm, dry air). Then sand lightly with P240 grit paper — just enough to smooth the raised fibers without going too deep. Worn or slightly dull sandpaper works well for this purpose.

If the surface still feels rough, repeat the process with a second round of wetting and sanding, this time using finer grit like P400 for an even smoother base.

Sanding the Instrument

The purpose of sanding is to create an ideal surface for finishing and to do this we need to create a smooth surface, remove imperfections and machine marks that affect your finish. Note that your body and handle have been pre-sanded with grit P180.

First, here are some important rules to follow during the sanding step:

• ✓Always sand in the direction of the grain (forwards and backwards with the grain) never on the side. For the sides and edge of the body it may be more difficult to sand in the direction of the grain in which case always sand in a direction that you have predefined.
• ✓Sand first with a P240 grit, then P400 in the case of a stain. This step of smoothing wood with different grain levels is important. Each step P240 and P400 has its uses.
• ✓Cavities that will not need to be painted since they will be covered by one of the components, pickguard pickups, etc. do not need to be sanded.
• ✓Sand all flat faces and outlines well, and don't forget the hard-to-reach places. Then clean with a rag or with a fan to remove all dust and wood catfish.
• ✓You should ALWAYS use a sanding block on the flat surfaces of your guitar (or a rotary sander if you have).
• ✓When using the polishing pad or sandpaper clean it often. To do this pat and rub lightly on a rag surface to remove the dust embedded in your sandpaper. When the sandpaper becomes very worn, replace it.
• ✓When sanding the edges of your guitar or delicate areas of the neck, remove the sanding block and simply slide the sandpaper between your fingers against the surface. It takes longer but will result in a better finish and allow you more control.
• ✓When satisfied with your job, be sure to remove all sanding dust and grits with a vacuum, damp cloth.

Sanding by hand: This is a bit of a tedious but essential step and it is important to do it well to get a good result.

Sanding with a machine: If you have a rotary sander (excentric), don't hesitate - they'll make your life a lot easier. But take it easy!

Sanding the contours: A rotary sander is no longer appropriate here, as it can easily round off or damage the delicate curves and edges of your body. Switch to hand sanding with a soft block or flexible pad to maintain control and precision. Once your contours are smooth and consistent, you're ready to move on to the next step: applying the grain filler.

General Information

Wood filler especially important for woods with open pores such as ash and mahogany. The filler will allow you:

• Use less paint or varnish because, without the pore filler, the lacquer will clog instead of the pore filler.

• Smoother and smoother finish without small pinholes

• It can also be used at the same time to pre-color your wood: black stain, mahogany, neutral wood, etc.

• It will allow a better quality finish less expensive.

Apply Wood Filler Before, After, Or Mix With dye: The guitar maker suggests either applying mixer with a wood filler or after the filler. The choice depends mostly on the intensity of shade you are looking for. You have three levers to control the intensity: dilute your dye more or less with white spirit, apply more or less layers of dye; and finally fill the pores to a greater or lesser extent (this having the pores open when tinting, which can be obtained by mixing the pore sealer with the tincture). If you want to mix your stain with the sealer, we recommend that you use a natural grain filler (to stay as close to the color of your stain as possible) with some tincture and white spirit.

The consistency of your final mouth pore - whether or not to mix with tincture - should be a little more runny than melted caramel and a little less than custard.

Preparation

To apply the pore filler we invite you to wear gloves although this is not harmful. We suggest that you mix our mouth pore with a little water. Let's say 10-20% lukewarm water. This will allow for easier application and avoid creating patties that would have to be sanded down painstakingly.

Application

To apply the pore sealer you can either use a cloth or a plastic card. Our preference is to use a cloth for its application and a plastic card to remove the excess while rapping.

Collect the pore sealer with your cloth and rub, pressing firmly in a circular fashion throughout your body (and handle, if you have decided to sublimate and fill the grain of your sleeve). The idea is indeed to fill the pores and you can imagine that you have to push the sealer into the pores, the interstices of the wood.

Surface, wait 2-3min, no more, then scrape off the excess pore sealer from the wood surface with a plastic card provided. The goal is for the mouth to only pore in the interstices and thus maintain a smooth surface. It is preferable to grate perpendicular to the direction of the grain so as not to remove the filler lodged in the interstices of the veining. Then do the other surfaces in the same way. In more difficult-to-scrape areas you can use a clean cloth in place of a plastic card to remove excess sealer. Remember to treat the edges as well. These areas are easy to overlook.

Once all the surfaces are done, let dry for 1 hour then sand with P400 grit sandpaper as defined in the previous section above. Be careful not to sand too much. You don't want to remove the sealer you just applied. Sand the edges carefully as well.

Finally, inspect your work. You can easily see if all of the pores are filled by looking at the surface at an angle, against bright light radiating obliquely toward the surface. If you missed any areas, you can always reapply wood filler.

Manage the bindings: The bindings should have been carefully masked off before you began painting or finishing. Once the rest of the guitar is complete, you can remove the masking and inspect the bindings. If any finish has bled over the edges, use a sharp blade or fine polishing tools to clean them up gently. This final step adds a professional touch, highlighting the clean lines and craftsmanship of your instrument.

Primer Application

• Sand previously with P600 grit before applying the primer.
• Before using the spray, make sure it has been stored at room temperature (for paint fluidity).
• Shake vigorously for at least 3 minutes.

Apply 2 to 3 thin coats for the body and 1 to 2 thin coats for the neck if you choose to paint it. It should not be necessary to sand between coats unless you have drips, runs, or nibs. In such cases, use P800 grit sandpaper.

Once finished, you can very gently sand with P800 sandpaper, applying almost no pressure. The goal is not to remove material or paint but merely to smooth very lightly and remove minor imperfections.

Color Application

Just like with the primer, it's now time to apply your colored nitrocellulose spray. Work in a well-ventilated area and spray in smooth, even strokes, maintaining a consistent distance from the surface. Apply 2 to 3 light coats on the body, allowing each layer to dry thoroughly before adding the next. If you're planning to paint the neck as well, 2 thin coats are usually sufficient. Once the color coats are complete and fully dry, you can perform a very gentle sanding with P1000 grit sandpaper to smooth out any small imperfections or dust particles—being extra careful not to burn through the color layer.

General Information

Most store-bought electric guitars are finished with polyurethane, but we have opted to provide you with a nitrocellulose spray lacquer (nitrospray). Nitrocellulose lacquer offers a traditional, vintage-style finish that enhances the natural resonance of the wood. However, it requires more care in application and longer drying times compared to water-based alternatives. Please keep in mind the following recommendations.

• ✓Before starting the varnishing step, make sure your wood has been sanded to at least P400.
• ✓Apply very thin coats to achieve an even and smooth finish.
• ✓Applying nitrocellulose lacquer is a delicate process, so take your time.
• ✓Unless you prefer otherwise, fretboards are typically left unvarnished. Instead, consider applying Tru-Oil or lemon oil for better playability.
• ✓Inspect the surface carefully after each coat to detect any imperfections or drips.

Preparation

Before use, shake the nitrocellulose spray can thoroughly for at least 2 minutes. It is crucial to ensure the lacquer is well-mixed for an even application. Prepare your guitar body as described in the previous sections.

Application

Apply the nitrocellulose lacquer in thin, even coats. Hold the spray can approximately 20-30 cm from the surface and spray in smooth, overlapping passes. Work in a dust-free, well-ventilated area, preferably with protective gear such as a mask and gloves.

Always spray along the grain direction. Start with the top, then move to the sides and back. Allow sufficient drying time between coats to prevent defects.

For the first two coats, do not sand between layers unless you notice significant drips or orange peel texture. If needed, use P600 sandpaper for minor corrections. Ensure that each coat is completely dry before applying the next one. Given nitrocellulose's properties, drying times will vary depending on humidity and temperature.

For the third coat onward, allow at least 24 hours of drying time before sanding lightly with P800 sandpaper. This gentle sanding helps the next coat adhere properly and ensures a smooth surface.

The final coats should be applied with extra care. Let the lacquer cure for at least 7 days before proceeding to the final sanding and polishing steps. Below is a summary table of the varnishing process.

Want to dive deeper into the differences and best use cases for wet vs. dry sanding? Check out our full guide here.

Once all coats have been applied, let the lacquer cure completely. If you have applied 7 coats, allow at least 7 days before final sanding and polishing. The longer you wait, the better the finish will be.

After curing, remove the masking tape from areas such as the fretboard, nut, or bindings. If the bindings have absorbed some color, gently scrape them with a razor blade to restore their original appearance.

General Information

Polishing is optional, and normally, even without it, you should already have achieved a very nice result. However, if you want more shine and an even smoother surface, we invite you to undertake this final finishing step. Polishing can be divided into three stages: leveling sanding to remove the last defects, sanding for polishing, and finally buffing. These steps will be further detailed below. Also, take note:

• Always be careful when sanding, applying very light pressure, especially near the edges. It is easy to remove varnish if you press too hard!
• Always ensure you remove all dust generated by your work environment or sanding. One idea is to run a fan simultaneously to remove dust immediately.
• From time to time, "tap" or rub your sand paper on a mat to remove embedded dust.
• For a water-based finish, do not sand with water. Use a dry sanding method. If you sand with water on a water-based varnish that has not completely dried, you may slightly remove your varnish layer.
• When using water, always use room temperature water. Cold water can damage and crack your finish.

Before starting, the wood should have already been sanded with P800 or P1000 grit in the previous step.

Preparation

Before you begin, make sure you have both dry and wet sand paper on hand in grits P1000, P1200, P1500, P2000, and P2500. For optimal results during sanding, we recommend placing your guitar on a soft, stable surface—like a carpet or thick towel—to protect the body from scratches and ensure even pressure as you work.

Processing

Leveling Sanding: This step is only necessary if you still have localized imperfections (such as drips or significant roughness). In this case, you should sand down to P400 to remove the imperfections, then progress to P600, P800, and P1000. For localized sanding, the sandpaper is smaller, and a smaller sanding block—is used, as it is a very localized sanding process.

Polishing Sanding: For the polishing step, refer to section IV. However, please note that this time, you should apply minimal pressure while sanding. The goal is to erode the surface, not remove material, but to eliminate slight surface imperfections created during the varnish application.

Start sanding with P1000 grit, then move to P1200, P1500, P2000, and finally P2500. Some prefer to continue, but you won't notice a significant difference. Always remove dust using a running fan to prevent it from scratching your finish further!

At this stage, you should have a slightly whitened finish with micro-scratches removed. You can see this clearly by placing the wood near a light source and tilting it slightly to create reflections that make these scratches more visible. If you see micro-scratches, return to P1000 grit and work up to P2500.

It is now necessary to buff your wood to transform the whitish surface into an ultra-glossy finish.

Buffing

This is the final step, where additional products must be applied. You can either use dish soap mixed with water or apply dedicated polishing products, such as those available on our website. In particular, our polishing kit contains everything necessary for sanding, polishing, and hand buffing (a specific guide for polishing with this finishing kit is also included). Naturally, using products specifically designed for guitar buffing will provide much better results.

The selected polishing product can be applied either by hand or by machine.

By Hand: We recommend using microfiber cloths. Rub in circular motions, applying light pressure. Rinse and continue until you are satisfied with the result.

With a Machine: While dedicated polishing machines exist, you can easily use a drill with a polishing attachment to buff your guitar effectively. Always keep the drill moving at a moderate speed to avoid overheating the surface, as excess friction can damage the finish. Start with a firm pad for initial polishing, then switch to a softer pad to enhance the shine and achieve a smooth, glossy finish. Be aware that some areas may be too tight or curved for the machine to reach.