In this post I want to go over a problem that many DIY painters experience and a handful of simple solutions. That problem is brush marks.

Today, I want to particularly address brush marks when painting a door, either cabinet doors, regular doors or really any piece of wood or furniture that you want to eliminate brush marks on. I am going to go over howto get rid of them and how to avoid them in the first place.

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Getting Rid Of Existing Brush Marks

Many DIY painters are most likely in the process of painting already painted doors and therefore could be dealing with thick brush marks from the last time these doors were painted.

Sadly, I don’t have any special tricks that will simply eliminate these brush marks, but rest assured, they can be eliminated.

You Will Need:

• A Random Orbital Sander
• 100 Grit Sanding Discs
• 120 Grit Sanding Discs
• 150 Grit Sanding Discs

I like to remove the door and lay it flat on either a work table or two saw horses. This allows me to work on the door easier than if it were hanging (it is also the way I like to paint the door).

Start by placing your 100 grit sanding disc onto the random orbital sander. Slowly sand down the door until you have eliminated all of the brush strokes. Once you are done sanding out all of the brush strokes, you will want to sand out the deep scratches left by the 100 grit paper. I find that 120 or 150 grit is perfect for pre-painting sanding. Switch to your 120-150 and sand down the door thoroughly before moving on.

A few notes while sanding your doors:

1. If the door is a six panel door, I never worry about brush strokes in the grooves. I only sand the flat areas and the doors turn out great. Groves would have to be sanded by hand and that would take ages.
2. Do not push down on the orbital sander. Any extra pressure will only cause more wear on your motor and thus kill your sander quicker. Let it do its work on its own, I use my hand to guide the sander and let the weight of the machine do all the work.
3. Check your doors for lead paint before sanding. You can get a lead test kit here.
4. Lead or no lead, always wear a NIOSH approved safety mask when sanding.

How To Paint Doors Without Brush Marks

Now that you have sanded out any existing brush marks (or are starting with un-painted doors), you are ready to paint. Here are the tricks I use to make sure I don’t end up with brush marks:

Add Floetrol To Your Door Paint

Floetrol is a paint conditioner, not a paint thinner like water and is the number one thing you can do to eliminate brush and roller marks.

When you thin down paint with water it actually covers less and loses some of the qualities it was built to have. With Floetrol, your paint will keep it’s coverage, thin (condition) the paint so it lays smoother and slow down the dry time to increase leveling. When Floetrol is added to your paint, you will easily eliminate 75-90% of your brush marks.

If you are using an oil based product, use Penetrol, this is basically the same product only for oil based paint.

Paint Your Doors While They Are Laying Flat

By removing your doors and painting them flat you receive a handful of benefits. By painting your doors flat, you will be able to apply a thicker coat of paint without the risk of getting runs. If your paint is thicker, your brush and roller marks should have more time to level off into the finish. You’ll also have gravity on your side by painting your doors on a flat surface, which will help the marks sink into the finish.

You also get some extra benefits by removing your doors and painting them flat. The first is that you won’t have to paint over your carpet/flooring. Second, you won’t get any paint on your hinges (which MANY DIY painters do when painting doors).

Use a 4′ Roller & Velour Cover On Flat Areas

Another easy (and quicker) way to eliminate brush strokes is to use a brush as little as possible. A velour roller cover and a 4″ roller is the perfect way to go.

Velour covers are incredibly short nap rollers that do not shed and leave as little texture from the roller as possible. A velour roller cover with a flat laying door and some Floetrol and your doors will like as though they have been professionally sprayed.

The way I paint doors (when I am not spraying) is to start by brushing any of the grooved areas that I cannot get my roller into. Once those are done, I go over all of the flat areas with my velour roller.

Sand Thoroughly In-Between Coats

An extremely important step to achieving no brush marks in your finish is to make sure and sand thoroughly between coats. After every single coat, whether primer or top coat make sure to sand with a sanding sponge.

Before primer, I like to use a medium grit sanding sponge (if I am not using a random orbital). In-between coats of primer and before my first top coat, I like to use fine sanding sponges and finally, in-between top coats I like to use extra fine sanding sponges for all my sanding.

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Apply Your Primer Correctly To Eliminate Brush Marks

Primer is usually the biggest culprit of brush marks because it goes on thick and dries fast. This means that the paint doesn’t have time to level out and lay smooth after you brush or roll it on. Look for a slow drying primer or try adding Floetrol or even water to thin down the primer.

**Painters Trick**

This is a trick I use to get my doors to be incredibly smooth (literally, not a brush stroke, roller mark or slightest sign of grain on them!). This technique will make your primer coat perfectly smooth and hide thick grains such as oak grain if you are painting oak doors. It takes some extra time and work, but the results are incredible.

Apply your first coat of primer and lightly sand with a fine sanding sponge when the primer is dry. Now you are going to apply another coat of primer, let dry and sand again. Repeat for a third time. Make sure to still apply your primer in a way where you are creating as few brush strokes and roller marks as possible.

Once your third coat of primer is fully dry, get out your random orbital sander and 150 grit sanding disc. Lay the door flat again and lightly power sand your primer until you get a flawlessly smooth finish. Remember don’t press into the sander, let the weight of the sanding and the random spinning motion do all the work. Do not sand through the primer back to the raw wood or you will have to re-prime.

This trick works because the three coats of primer build up a thick sandable surface. It should easily sand to a perfectly flat finish.

Hopefully with these tips and tricks you will be able to get doors that turn out perfectly smooth and aren’t covered with those unsightly brush and roller marks! Happy Painting!