You can paint over most finishes. But, can you paint over stain?
You can paint over wood stains as long as the finish wasn’t sealed with a moisture-resistant sealant. This is because they don’t have any chemicals or resin in the formula that can repel paint.
However, you’ll need to do some prep work first. The coating needs to be sanded, cleaned, and primed. This is to allow the paint to stick and dry properly.
Paints sticks to stain, but not to every type of it. They stick to water-based stains because they don’t have chemicals or resins that can repel liquid. As such, they will easily bite into and stick over them.
You can also paint over the oil-based stain, but it’s harder because the adhesion is weaker. That’s because they have a high volume of chemicals and resins that will not let a coating stick over them.
Oil-based stains have a natural glossy and hard finish that will prevent coatings from biting or sticking properly. You must sand its glossy finish off, apply a few coats of primer, and then paint over it. If you do it directly, there will be a weak adhesion and the finish might peel off.
Paints also don’t stick to sealing stains like gel, lacquer, and varnish. These stains have moisture-resistant properties meaning that moisture (either oil or water) will not stick over them or penetrate them. Since all paints are water- or oil-based, they won’t stick to a sealing finish regardless of the type.
You must remove the sealing finish first, and then prime the surface to paint over it.
To know if the paint will stick to stain, you can use the alcohol test. Dampen a rag with alcohol and use it to wipe the finish. If the stain comes off, it is water-based. If it doesn’t come off, it’s oil-based and you’ll have to remove or sand it.
You can also check the container to know if it’s an oil-based, water-based, or sealing stain.
Related Read: Can You Stain Over Paint?
Do You Need To Sand or Prime?
You don’t need to sand or prime if the finish is water-based. This is because water-based stains have a very low volume of chemicals, so they don’t have a natural sealant or glossy layer. So paint will stick properly to it without sanding or priming.
However, if you paint without sanding or priming, the finish will not come out smooth. This is because the finish will have been affected by dust, grime, and dents. Sanding helps to remove all these. So, without sanding them off, the finish will come out rough.
Also, priming helps seal and cover holes, cracks, and imperfections in the finish. Without sealing these, the paint when applied will be sucked and this will lead to wastage, thick coats, and a longer dry time.
Never paint over an oil-based or sealing stain without sanding and priming first. Paint will not stick to these stains because they are hard and usually moisture-resistant. So, it’s compulsory to sand and prime first.
Related Read: Paint vs Stain
Do You Have To Remove It?
You don’t have to remove stain before painting. You should only remove it if the finish will prevent proper adhesion.
For instance, if you want to paint over a lacquer stain, you’ll need to remove the finish because it is moisture-resistant and will prevent good adhesion. However, you don’t have to remove a water-based finish because it doesn’t have a glossy finish or additives that can repel paint.
But, you don’t have to remove the existing finish entirely even if it’s oil-based. You can simply sand it to abrade it. When you sand, you create tiny pores (holes) and scratches in the finish that the paint can bite into when applied.
How To Paint Over Stain?
Here are the tools that you need:
- Medium-grit sandpaper
- A scraper
- Paint stripper
- A mixer or turning stick
- A bucket
- Portable vacuum
1. Find The Type of Finish
First, find the type of finish you have (water or oil-based). When you know the type of finish, you will know how to prep it.
To know the type of finish, use rubbing alcohol. Pour some alcohol on a clean rag and use it to wipe the finish. If the coating comes off, it’s water-based. If it doesn’t come off, it’s oil-based or sealed.
2. Remove The Stain (Only For Oil-Based)
If the finish is oil-based or sealed, you must remove it. That’s because they have a glossy finish (layer) that will prevent paint from penetrating and sticking over them.
Removing them is difficult because they penetrate deep into the surface. So it might be impossible to remove all of it. Luckily, you don’t have to remove all of it, you just need to remove enough so the paint can bite into and stick properly.
To remove the stain, use a paint-stripping compound. Apply two thick coats of stripping paste over the finish and leave it for a few minutes. The stripping compound will soak into the finish and soften it. After 10 minutes, scrape it off with a scraper.
3. Sand The Finish
After removing the finish, you need to sand the surface using medium-grit sandpaper (150-grit). This step isn’t optional and should be carried out even for water-based finishes. Sanding helps to remove imperfections on the surface so the finish can come out smooth.
After sanding with medium-grit sandpaper, you need to even out the surface using fine-grit sandpaper. After sanding, remove the dust.
4. Apply Two Coats of Primer
If are using water-based paint, use latex or water-based primer. If you’ll be applying an oil-based paint, use an oil-based or enamel primer.
Two coats of primer are enough to cover and seal the finish. Allow each primer coating to dry enough before re-coating.
5. Apply The Paint
To apply paint, use a paintbrush, roller, or sprayer. The sprayer applies it better, but you must thin paint before using it. Wait until one coat dries before applying the next one. Don’t apply thick coats as it will take longer to dry.
Depending on how much stain is left on the surface, you can apply 2 or 3 coats of paint over it. Once the final coating dries, seal the finish with a sealant such as polyurethane to increase its durability.
Types of Stains You Can Paint Over?
Oil-Based Paint Over Water-Based Stain
You can put oil-based paint over water-based stain because the finish doesn’t have any chemical or top coat that will repel the oil-based paint. Also, since water-based stains dry smooth and fine, you don’t need to apply a primer.
Water-based Paint Over Oil-Based Stain
You can’t put water-based paint over an oil-based stain because its finish has a natural glossy layer that will prevent the water-based paint from sticking. So, you have to remove the finish first before applying it.
You can paint over wood stain but the finish won’t come out smooth. This is because wood stain penetrates wood very deeply. So, paint can’t penetrate the surface and will have to sit over the stain layer. This leads to a weak adhesion and the finish can be removed easily.
So, it’s advised to clean, sand, and prime the finish first.
You can’t paint over gel stain because its finish is moisture-resistant which will prevent any type of paint from sticking. Also, it has a very slick surface. If you paint over gel stain, the finish will come off in weeks.
So, you must remove the entire coating, or at least sand its glossy layer first.
You can paint over miniwax stain only if you prep the finish first. Miniwax is an oil-based stain, so you need to remove its finish first. You can remove it using a paint stripper, scraper, or solvent.
Concrete stains are water-based, so you can paint over them. But, the finish will come out rough. So, to achieve a smooth finish, you’ll need to sand and prime the finish first.
You can’t paint over deck stain unless you remove the finish first. This is because deck stains are exterior finishes, meaning they are moisture-resistant, hard, and weather-resistant. Therefore, paint can’t stick to such type of stain unless you remove it first.
Stains That You Can’t Paint Over
- Oil-based stains
- Exterior stains
- Deck stains
- Sealing stains like gel, lacquer, and varnish
- Sealed stain – This means a stain that is sealed with a top coat.
In summary, you can paint over some types of stain, such as water-based or non-sealed stains. However, if the finish is sealed or oil-based, you must clean, sand, and prime it first or the finish won’t come out smooth.
Tony is a professional painter and an author of DIY Geeks. Tony has completed over 1,000 painting projects for his clients. It's safe to say he knows what he Is talking about,