Maybe you have an old primer coat that you want off your furniture or you applied primer on wood wrongly, and you want to remove it. How do you do this?
There are different ways to remove a primer coating from wood. You can use a paint stripper to absorb it and scrape it off after. It’s better to use a biochemical or organic paint stripper for this because it will not damage the wood.
You can also sand it off using medium-grit sandpaper or dissolve the primer coat using an alcohol or petroleum-based solvent.
Oil-based vs Water-based Primer Removal Method?
You can remove oil-based and water-based primer from wood using the same methods. Sanding is usually the safest and most effective way to remove it, and it works on both primer types. Organic paint strippers, such as Citristrip, also work on both types.
The only case where you might need to use different methods is when you are using a solvent. To use a solvent to remove a primer coating, you need a product that can dissolve it – the solvent has to be the same base as the primer coat.
So, for water-based primers, you can use water to dissolve and wash it off. But, you can’t use water to remove oil-based primer because water isn’t strong enough to dissolve it.
In this case, you’ll need a petroleum-based solvent, such as mineral spirits, to dissolve and remove the oil-based primer. Alcohol-based solvents, such as acetone, can dissolve oil-based and water-based primer coats.
How To Remove Primer From Wood?
If the primer hasn’t dried yet, you can use a dampened rag (with water or rubbing alcohol) and wipe the coating off. However, if the primer has dried, you need a stronger method/solvent.
Here are 4 methods you can use:
1. Sand it Off
Sanding is usually the safest and most effective method to remove primer coating from wooden surfaces. Many professional painters use this method because it doesn’t damage the wood. Instead, it smoothens the surface, so you can reapply primer or paint almost immediately.
Tools you need:
- 80-220 grit sandpaper.
- Orbital sander for large and vertical surfaces
- A shop or portable vacuum
- Liquid cleaner (or dish soap and water)
- A paint scraper or plastic putty knife
- Rags
- Safety goggles.
Here is a detailed guide:
1. Wash The Surface
First, wash the surface using a liquid cleaner. The purpose of this is to remove filth on the surface, especially if you are working on old furniture.
To do so, place a rag in a bowl of liquid cleaner or dish soap mixture. Then, use the rag to scrub and wash off the filth from the wood. Dry the surface with a rag after and leave it for a few minutes to dry.
2. Scrape it Off
Next, scrape some of the primer coatings with a plastic putty knife. You won’t be able to remove all the primer, but that’s not the goal. The goal is to remove as much primer as possible, so when you sand it the sander doesn’t have to remove as much.
After scraping, wipe the surface with a rag.
3. Start Sanding
For large and vertical surfaces like walls, you’ll need a power sander because sanding manually will be time-consuming and tiring. For small furniture like your shelf, cabinet, and drawer, you can sand manually.
If you are using a power sander, attach medium-grit sandpaper (80-grit) to it. If you are sanding manually, wrap the sandpaper around a sanding block.
Use the abrasive side of the sandpaper to scrub directly on the wooden surface. Ensure to sand along the wood grain and finish on one spot before moving to the next.
As you sand, inspect the dust coming off. When you see wood shavings or sawdust, you should stop sanding that spot because this means you have removed the primer and reached the wood surface.
After removing the primer coat, move to a finer grit to smoothen the wooden surface.
4. Vacuum the wood
The final step after sanding is to vacuum the wooden surface. You should also vacuum the dust on the floor, so your work area is neat.
2. Use a Paint Stripper
You can also use a paint stripper to remove a primer coating. It’s better to stay away from caustic strippers because they contain sodium hydroxide that can damage your wood and cause different problems. You should use a biochemical or organic paint stripper like Citristrip to protect the wood from damage.
Here are the tools you need for this method:
- Citristrip
- Safety goggles.
- A plastic paint scraper
- A paintbrush
- Mineral spirits or acetone
- A large nylon or plastic bag
- White vinegar
- Liquid cleaner
- Rags
Here is a detailed guide:
1. Clean The Surface
First, clean the surface. If you don’t, the filth and dust will prevent the paint stripper from working properly and removing the primer effectively.
To clean the surface, damp a rag with liquid cleaner or dish soap mixture. Use the dampened rag to wipe the surface, and wait for the surface to dry.
2. Apply The Paint Stripper
Once the surface is clean, apply the paint stripper directly to the wood. You want the stripper coating to be very thick, so apply as much as you can. If it’s too little, it will dry up before it can work into the surface.
After applying your Citristrip, cover it with a nylon or plastic bag for at least 30 minutes. This improves the efficiency of the paint stripper compound.
The way paint strippers work is they absorb the primer coat from the surface and then dry over it. Once the stripping compound dries, you can scrape it off and the primer will come off too.
3. Cover The Floor
Before scaping, cover the floor with a garbage bag or big nylon to prevent a messy workplace. You don’t want to spend the next 2 hours cleaning up your space.
The nylon will collect the stripped primer as it falls off, making it easier to dispose of and clean up after.
4. Start Scraping
Using a plastic putty knife, start scraping the paint stripper and primer coat. Since the primer coat has already been absorbed by the stripping compound, it will come off when you scrape off the paint stripper.
Ensure to scrape gently, so you don’t gouge the wood. A
4. Neutralize The Paint Stripper
After stripping the primer coat, you need to neutralize the paint stripper with white vinegar because the leftover stripping compound can damage the wood and prevent the paint from sticking later.
Pour some white vinegar into a clean bowl and mix with warm water. Then use a rag and the vinegar mixture to wipe the wooden surface. Leave it to dry.
3. Use a Solvent
Another way to remove a primer coating from a wooden surface is to use a solvent. A solvent will dissolve the coating, making it easier to scrape it off.
You can use mineral spirits or turpentine for oil-based primer. For water-based primer, mix a tablespoon of vinegar with some dish soap and warm water. Acetone is also a good choice for both types.
Here are the tools and supplies needed:
- A bottle of acetone
- Rags
- Paint scraper
- Plastic bags or nylon
- Liquid cleaner
- Safety goggles.
Here is a detailed guide:
- Clean the wooden surface.
- Pour some acetone (or another chosen solvent) into a clean bowl and dip a rag in the bowl.
- Use the damp rag to wipe the primed wood. Ensure to massage the solvent into the wood properly.
- Leave the solvent on the wood for 15-20 minutes.
- After 20 minutes, the primer will get dissolved and you can scrape it off.
- Apply more solvent to the leftover and wait 20 minutes.
- Wipe and clean the wood to remove any solvent residue and leave it to dry.
4. Power Wash – For Wooden Floors
To remove multiple old primer coatings from a wooden floor, use a power wash. For this method, you’ll need a garden hose or pressure washer. The trick is to hose down the floor with water at high pressure. This will wash off the primer and paint coats.
Optionally, you can apply some vinegar on the floor and leave for about 30 minutes before you power wash. The vinegar will loosen the primer coat, so it comes off easily when you power wash.
When you complete this method, you should leave the floor to dry for at least 24 hours. You should also sand it with a power sander before repainting because power washing will raise wood fibers.
FAQ’s
Do You Need To Wipe Off Excess Primer?
Usually, you don’t need to wipe off excess primer after application. This is because most primer paints are self-leveling meaning that they dry evenly on the surface when applied. Also, you only need one coat of it, so it’s unlikely you’d apply too much from just one coat.
However, you should follow the manufacturer’s instructions when applying it. If the instructions state to wipe off the excess after application, you should.
How Long Before You Can Re-apply It?
This depends on the removal method that you used to take off the primer. If you sanded it off, you can re-apply primer or paint almost immediately because the sandpaper will remove the coating and smoothen the surface to make it ready to re-paint it.
However, if you used a paint stripper or solvent to remove the primer, it’s advised to wait at least 12 hours before re-applying it. This is to give the surface enough time to settle before accepting new coatings. This also gives you enough time to neutralize the stripping compound or solvent residue on the wood.
If you power washed the wood, it’s best to leave it for at least 24 hours because the surface needs to completely dry before you can re-paint it.
