Whether you plan on finishing that body you just cut to perfection, or you just want to bring some life back to that worn-out favorite instrument, preparing a guitar body for paint requires some planning, preparation, and careful execution.
Surely painting a guitar body can appear to be lots of fun, but it’s fairly easy to miss some crucial steps.
And in that case, you might end up with an instrument that won’t look the way it should and you’ll have to start over. This translates to time and money not so well spent.
Executing the guitar painting procedure wrong alone can ruin the whole project of building or restoring guitars.
In case you’re restoring an older guitar, we’ll consider in this article that you have already disassembled all the parts, such as the neck (in case it’s bolt-on), the hardware itself (bridge, pickups, pickguard, etc…) and you have a guitar body that’s ready to start.
Can you paint a guitar without taking it apart?
When preparing a guitar body to apply paint, an option *that we wouldn’t recommend based on previous builds), is to cover the hardware and other parts you don’t want paint on with some type of masking tape.
You can in fact achieve good results with this method, but it must be accurate and with the correct materials, otherwise, you won’t be able to sand and paint properly.
Do you have to strip a guitar before painting?
If you plan on restoring an already painted guitar: You must:
- Remove the finish and the old paint before anything else. Some paint jobs will allow you for removal using paint remover.
- This should be easy as applying the product, waiting for it to do its magic, and getting the paint off with a scraper
- Some other guitar finishes won’t be so easy, and will only allow for removal using sandpaper. Patience, good sanding paper and strong arms will take you far, just make sure it isn’t far enough as to removing too much of the wood itself.
Once that is ready, or if you have a new body that you just cut/bought from a kit, the process of sanding goes as follows…
How do you sand a guitar for painting?
To guarantee that no imperfections are in the body after the actual painting, proper sanding is the best way to go.
Considering the guitar body is ready from the cutting perspective, you can start by feeling it with your hands and looking carefully to spot imperfections, and try your best to smooth it using sandpaper.
- The thing with sandpaper and wood is that you should repeat the process of sanding while decreasing gradually the actual grit size(increasing the grit number in the specification). This results in a more even surface.
- The quality of the sandpaper is important. There have been many scientific advancements in the industry for the past decades. Nowadays, the good brands have the little abrasive particles such as aluminum oxide or silicon carbide aligned with their pointy tips upwards, through the use of magnets, so that they can be used more and offer better sanding
If your guitar body is already close to having no imperfections, you could start with a grit of 240, then proceed on to a 320, and lastly a 400 grit. These are fine grits. Above these numbers, they’re usually intended for detailing and polishing jobs.
Tools for sanding guitar bodies before painting
- The right tool to accomplish this task can vary. A palm/hand sander will do the job just as efficiently as a belt/spindle/drum sander if you have the patience and the skills for it.
- Sanding by hand is also an option, especially when you’ve gotten to the point of painting without the use of power tools. Chances are that you won’t mind a bit more sanding, after all, you just went through.
Once you are sure the body is smooth enough, all that is left is to wipe any wood dust and other residues. You can achieve this with a clean and soft lint-free rag, or a vacuum cleaner.
Filling the grain – Preparing a guitar body for paint
Some types of wood (like ebony, pau-Ferro, and alder) are non-porous, which means that filling will not be as much of a necessity, and rather an aesthetic choice to reveal the wood grain.
Other woods such as ash and oak tend to have more pores and will require that you use some kind of wood filler to make their surface even enough for the paint, as well as revealing the grain if that’s the case.
The process of filling in the grain – Preparing a guitar body for paint:
- Most products will require that you mix a certain quantity of water on them before using them. Check the instructions, and mix the product with water in another container. You can simply put the lid on the remaining product and store it for later use.
- To effectively apply the product to the body, you can use a brush or something like a spatula with a flat surface. Some people will recommend a rag, and others even prefer doing it with their hands to feel the pores’ locations better.
- You should test these methods on a leftover piece from the cutting to see what feels right for you and looks best with the particular wood you’re using
In any case, to ensure that you are completely sealing the pores, it’s best to work a bit of pressure in both directions of the grain.
As soon as you finish filling in the grain, remove any excesses immediately. This must be relatively quick, given that the products will harden as soon as the water evaporates.
Scraping the excess filler
The scraping should be moderately delicate. Consider that right after applying, the filling starts to dry, and if you scrape it with excessive force, the bonds that are already forming in the molecules can result in the removal of the filling from the pores.
Best to get it right first try.
The last piece of the puzzle is to let the filler dry completely. The period that it should dry will be described in the product’s container and will vary depending on its composition.
After the filler dries
When the waiting period is over:
- Pick up the body and feel it once again for bumps and excess filler that could have accumulated on the body’s surfaces.
- After examining it closely, use sandpaper to remove any imperfections. 320 grit is a common choice here, but it’s ultimately up to you to decide what works.
Depending on the amount of sanding you had to make after the filling process, it’s a good idea to smear some of these sanding sealers over the body and sand it again with a 320 or finer grit sandpaper. This ensures that the body will be perfectly flat before you can proceed on to priming and finally, start painting.
Priming – Preparing a guitar body for paint
Primers are products that promote adherence of the paint to the surface, extend its’ durability (avoiding cracks due to pores/bumps), and protecting the surface below the painting.
- Primers and similar products have some properties such as a degree of elasticity, to help the paint stay in place and not break, even when the wood expands/contracts due to the outside temperature. But detailing these is out of the scope of this article.
- Although this isn’t a requirement in many cases, priming should be in place depending on the thickness of the paint material you plan to use on the body.
- Also, of the finish, if you’re seeking allows for light to traverse it (translucent), you shouldn’t use it at all.
- The right amount of primer/nitro layers you should use is directly correlated to being able to sand it consistently, without removing enough that would uncover the wood beneath the layers. On most projects, about 3-4 coats are enough.
- Let each layer dry before applying the next one. The time it takes will depend on the product you’re using, and the climate as well. On hotter days it can be anywhere from 30 minutes to 1 hour until it’s dry to the touch.
- Consider the many applications that primers have, and you’ll know that you must make sure you have one that is right for the type of work you’re doing
Again, testing is the best route to take. Get a similar scrap of wood or a leftover from the cut, and (ideally) apply all of the steps above to ensure the result will not only look good but won’t crack or chip easily before you get to do it on the actual guitar body.
What kind of paint do you use on a guitar body?
Talking about colors… well, if you didn’t plan this from the start it may take longer to decide than what it took you to get to this part. There is a huge variety of colors and finishes to choose from, readily available at any specialized store.
As far as paint composition goes, there are some proven kinds that professionals tend not to deviate much from, such as polyurethane and nitrocellulose. The latter is more readily available.
What kind of paint do you use on an acoustic guitar?
If you plan on doing decorations, it’s safe to use acrylic or oil paints, provided that after it dries you cover it with the appropriate finish coating.
When it comes to painting acoustic guitar bodies as a whole, you’ll find lots of opinions arguing that thicker paint coats can alter the acoustic properties of the instrument for the worse.
However, this is highly subjective, since it’s related to every individual’s perceptions.
If you’re dealing with a great-sounding or expensive instrument, and you want to be on the safe side, you can always dilute the paint with water, alcohol, or similar solutions (always check the paint specifications). This will allow for thinner coatings that won’t affect the sound of the instrument in a perceivable manner.
Final preparations to paint the guitar body
- Independent of what you choose, ensure that you are in a dust-free environment (dust is volatile and can end up inside the paint, which results in imperfections and smaller bumps after the finish.
- Also, follow the instructions in the can/package closely, especially when it comes to the drying period. The body can hang through the holes where the neck is bolted, but everybody will have their preferred way.
- Some even go as far as creating mechanisms to hold and simultaneously horizontally rotate the body. You can use your creativity a bit and try out to see what works best for you.
Rest assured that most starters won’t get the whole process right on the first try.
When actually painting the guitar, spraying is the most common method, hence the need to have the whole body surface easily accessible.
Skills with spray cans will develop over time, and you should always aim to avoid runs.
Paint runs occur when too much is applied to the same spot, and gravity does its thing. Though having the guitar set on a flat surface can avoid runs, the excess of paint gathered will make for an uneven finish.
Can I paint a guitar with a standard brush?
If you are done preparing a guitar body for paint, nothing will stop you from painting with a brush, other than the fact that the end product won’t look the same.
Having a bit of experience using spray cans, over time you can get very similar results to what mass-producing factories and skilled guitars builders do. So we recommend that you stick to spray cans, but in the end, it’s your guitar. The same applies to the finishing coats.
To sum it up
The process of preparing a guitar body for paint can look daunting, but after a couple of rides, you’ll eventually get the hang of all the steps it requires.
Following closely and developing the skills to master these skills will get you much closer to a professional paint job.
When you did everything else related to preparing a guitar body for paint, all that is left is to apply the paint layers, stain, clear coating, polishing the body to make it shine, and reassembling all the parts.
Independent of whether you’re restoring an old guitar or painting a new one, if you’re able to get it right you’ll have an instrument that’ll be a joy to look at after completion.
But always bear in mind that in the case of restoration, the actual monetary value of the guitar might decrease, since collectors will always prioritize original and well-maintained instruments.