Dun-dun-dun-dun! (dramatic sound effect)

Hello, DIYer! You’ve reached the most challenging phase of the painting process—the surface preparation!

Surface preparation will eat up your time. Depending on how big the painting project is, prepping usually takes more time than the actual painting. No matter how tedious it is, don’t skip this process because it’s the root cause of most painting problems. Done well, it will make the paintwork durable and long-lasting.

It takes a lot of effort but the steps are fairly simple. DIYers can totally pull it off! Here, we made a workflow that you can use as a guide if you need to prep previously painted surfaces. Read more below to get detailed instructions for each surface.

Boysen Tutorials: How Do I Prepare Previously Painted Surfaces? | MyBoysen

The General Step: Check the condition of the paint.

Your first step is to observe the condition of the old paint. This applies to all types of surfaces. Watch out for painting problems. Treat them first before applying any paint on it. You can’t just ignore them and cover them up with paint. Chances are the new paint won’t adhere to the surface and the painting problem will just resurface.

This is also the time to figure out what type of paint was used so you could prepare suitable paint products to go with it.

Boysen Tutorials: How Do I Prepare Previously Painted Surfaces? | MyBoysen

If the old paint is in good shape…

The old paint is in good condition if it’s still intact and it clings firmly to the surface. If that’s the case, you don’t have to coat it with a primer. You just have to clean and sand the surface. You may use a rag, mild soap, and water to remove dust, dirt, grease, or other contaminants. After that, lightly sand the surface. We do this step so that the new topcoat will adhere to the surface. Dust off sanding particles and make sure it’s dry before you apply the topcoat. Don’t forget that the new topcoat should be compatible with the old one.

Peeling Paint: The Common Enemy

Boysen Tutorials: How Do I Prepare Previously Painted Surfaces? | MyBoysen

Maybe, you skipped the primer. You probably forgot to clean the surface thoroughly before painting. Or you might have used an incompatible paint. These are some of the reasons why your paint is peeling. This happens when the paint film doesn’t stick to the surface anymore. If that’s happening to your walls, you have to scrape off all the loose and flaking paint. Then, wipe the surface with a damp rag. Let it dry before applying paint.

Read more about peeling here.

Note: If you’re repainting an old house, you have to be careful when scraping the old paint because it might have lead in it. This is why we mentioned earlier to research the old paint that was used, so you’d know the safe and proper way to prep the surface. Go to this website first to know more about how to safely remove lead-based paint.

Chalking Concrete Walls 

Boysen Tutorials: How Do I Prepare Previously Painted Surfaces? | MyBoysen

Here’s an easy test to find out if your walls are chalky: Touch the surface. If the walls are chalky, it would feel like it’s covered with white dust and that sticks to your hand.

When you’ve confirmed that it’s chalky, start by cleaning the surface. You can use a damp rag or brush to clean off the chalk powder and other dirt particles on the surface. Let it dry before applying BOYSEN Chalk Blocker B-7304. Wait for two hours, then you can finally apply the topcoat.

Know more about chalking here.

Note: If the chalking is severe, don’t try to save it. You have to scrape off all the old paint.

Mildew-infested Concrete Walls

Boysen Tutorials: How Do I Prepare Previously Painted Surfaces? | MyBoysen

If you’re repainting your bathroom walls, you’ll probably notice that some areas have dark unsightly patches. That’s mold or mildew! They feed on moisture so you will usually spot them on bathroom concrete walls, kitchen tiles, or wash areas. If you see them on your wall, you have to treat the surface immediately because it will eat the paint away.

You have to prepare a bleach solution. It’s easy! Just mix one part laundry bleach with three parts water. You can use a clean rag or a brush to apply the solution to the surface. Leave it on for 24 hours before rinsing it off. Dry the surface before applying paint.

Learn more about mildew here.

Rusty Metal Surfaces

Boysen Tutorials: How Do I Prepare Previously Painted Surfaces? | MyBoysen

If the surface is rusty, you have to take care of two things because it’s likely that the old paint is also peeling. Start by scraping off all the peeling paint and then wipe it with a clean damp rag. Grab a wire brush and sanding paper, and use them to get rid of loose rust.

Sometimes, you’d find that there is still stubborn rust on the surface even after sanding. When this happens, apply pure Boysen Metal Etching Solution B-71 on it. Let it sit for 10-15 minutes before you wash it off. Wipe it dry, then apply the primer to the surface at once to prevent rust from forming again.

You’re ready to paint.

Well done, DIYer! Finally, you have a clean and dry surface that’s ready to paint. Remember to follow the proper painting system. We call it PPT or prime, putty, topcoat. Start by priming bare surfaces. You can also apply putty to even out minor surface imperfections. Lastly, apply the topcoat.

If you want to know the right paint for your DIY painting project, check out our Choose Your Paint Tool.

Have your answers ready for the following questions:

  1. What type of surface are you painting?
  2. Are you going to apply it inside or outside your home?
  3. Is the surface plain or textured?

Boysen Tutorials: How Do I Prepare Previously Painted Surfaces? | MyBoysen

If you have more questions about surface preparation, you can write an email to ask@myboysen.com or drop a comment below. Our lines are also open to your immediate painting concerns, just give us a call at (02) 8363-9738 local 417 to 418 during office hours.



Yasmin Aguila is a copywriter at Boysen Paints Philippines. Interested in making paints fun and relatable, she produces quizzes and painting ideas for this blog. She claims that she is obsessed with yellow, but she always dresses in black from head to toe.

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