Painting interior doors may seem like a daunting task, especially if you’re new to painting woodwork, but if you get it right, it can transform the look of your home with somewhat minimal effort. 

Whether you’re painting a traditional wooden door or tackling more modern materials like uPVC or laminate, getting a smooth, professional finish is all about the right prep, techniques and tools. 

In this post we’re going to focus on wood and how to paint internal doors for that professional look, so let’s walk through the best methods and answer some common questions to help you achieve a flawless finish.

How Do You Get a Perfect Finish on Wood?

First things first, achieving a perfect finish starts with proper preparation of your interior door. You might be thinking this is a no-brainer, but you’d be surprised how easy it can be to get wrong.

Before you even think about opening a can of paint, make sure the surface is smooth and clean. Sand the wood lightly to remove any imperfections, and clean the surface of dust or debris. 

For painting bare wood, priming is essential. A good primer will seal the surface and create a smooth base for your topcoat. Use a brush for detailed areas and a roller for large flat surfaces, following with light strokes to eliminate marks. Don’t rush! Several thin coats work better than a single heavy layer. For perfectionists, sanding lightly between each coat of paint ensures smoothness.

Once primed and painted, the laying off painting technique (lightly brushing over the wet paint with a dry brush to smooth out brush marks) will help you achieve that even, sleek look.

These techniques can be applied to other forms of interior woodwork too, whether it be a door frame, skirting board or picture rail!

Preparing Your Wooden Door for Painting

That old adage of “fail to prepare, prepare to fail” has never need more true than when it comes to painting wooden doors, so here are some things you’d need to consider when prepping your wooden door:

Tools for Prepping

• Screwdriver: To remove the door from its hinges and take off any door hardware (like handles and locks).
• Sandpaper (120-220 grit): For sanding the door’s surface to remove old paint, smooth out imperfections, or prep bare wood.
• Electric Sander (optional): To make sanding faster and more consistent on flat surfaces.
• Tack Cloth or Vacuum Cleaner: For cleaning off sanding dust before you paint.
• Wood Filler: To fill in any cracks, holes, or imperfections.
• Putty Knife: For applying wood filler.
• Primer: Essential for sealing the wood, especially if you’re painting bare wood or covering darker colours.

How Much Sanding Is Needed Before Painting on Wood?

A light sanding is usually enough, unless the surface is damaged or heavily varnished or has an old paint job. 

Use a fine-grit sandpaper (around 120-180 grit) to “roughen up” the surface, which will help the paint adhere better. 

For painting hardwood or smooth surfaces, more sanding may be necessary to ensure the paint bonds properly.

If you’re dealing with bare wood, sand it down after every coat of primer and paint to remove any bumps. However, don’t over-sand and remove too much of the wood surface; just aim for a smooth, clean finish.

After every sand, be sure to thoroughly wipe down the door with a dry, clean tack cloth to remove any dust as this could cause issues with the paint later on.

Should You Treat Knots in Wood Before Painting?

Absolutely! Knots in wood can bleed through your paint over time, leaving unsightly stains on your newly painted door. Treating knots with a wood knotting solution or shellac-based primer will prevent this. 

If you’re painting softwood internal doors such as those made from pine, this step is especially crucial as softwood internal doors tends to have more visible knots that can ruin the final look.

Should You Sand Down Undercoat?

It’s a good idea to sand down the undercoat. This helps create a smooth surface and improves the adhesion of your topcoat. The smoother your undercoat, the better your final finish will be, particularly when painting on wood. 

Don’t skip this step if you want to avoid rough patches.

Painting Your Wooden Door

Now you’ve prepped your interior door to perfection, it’s time to get going with the paint. Here are a few things to bear in mind when painting which should help you achieved that high-end finish:

Tools for Painting

• Painter’s Tape: To mask off areas you don’t want to paint (edges, glass panels, etc.).
• Paint Brush (2-inch angled): For cutting in and detailed areas like edges or grooves.
• Foam Roller: For a smooth, even finish on flat surfaces.
• Paint Tray: To hold your paint while using a roller.
• Paint: Make sure the paint you choose is suitable for use on wood.
• Drop Cloth: To protect floors and nearby surfaces from drips.
• Laying Off Brush (optional): To smooth out brush strokes after applying the paint.

What’s the Best Paint for Wood?

The best paint for wood depends on the finish you want. Satin or semi-gloss paint offers a soft sheen and is durable, making it perfect for high-traffic areas like doors. 

Gloss provides a shinier, more durable finish, while eggshell and chalk offers a flatter, more vintage look, but both will likely need to be finished off with a top coat of wax to protect it or be repainted more frequently. 

To help you choose the right paint for your doors, we’ve put together a handy guide covering which type of paint is best for interior doors.

For painting external doors it’s a slightly different story, you will need to opt for weatherproof paints, and always use a primer first, especially when painting hardwood.

Can You Use Wall Paint on Wood?

Technically, you can use wall paint on wood, but it’s not ideal. 

Wall paints are usually matt or eggshell and water-based, which aren’t as durable on doors and will likely age or chip very quickly. 

For the best finish, use wood-specific paint such as satin or gloss. These are designed to withstand wear and tear, which is especially important for high-traffic areas like doors.

Do You Need to Sand Between Coats of Paint?

Yes, sanding between coats of paint is always worth doing for a professional, smooth finish. 

This step helps get rid of any brush strokes, dust particles or imperfections in the paint itself. 

A fine 220-grit sandpaper is perfect for this task – just a light sanding is all you need to knock down bumps before applying the next coat.

Why Does My Wood Feel Rough After Painting?

If your wooden interior door feels rough after painting, it’s probably because dust or debris settled on the surface while the paint was drying. 

The solution? Sand and wipe down your interior doors between coats. 

It’s a long winded process, but it works. Also, ensure the room is well ventilated but free from drafts, which can blow dust onto the wet paint. Wipe down surfaces with a tack cloth before you start each layer to keep things smooth and clean.

How to Eliminate Brush Strokes When Painting

To avoid brush strokes when painting internal doors, try the laying off painting technique. After applying your paint with a brush or roller, lightly brush over the wet paint with a soft, dry brush to smooth it out. 

A high-quality, synthetic brush or foam roller can also help reduce brush strokes when painting woodwork.

It’s especially useful for flat interior doors, large areas of woodwork, or when using gloss or satin paints. Just remember to work quickly – paint dries fast, and you want to lay it off while it’s still wet.

Using the right paint consistency is key too – if it’s too thick, you’ll see brush marks. Thin it down slightly if needed and apply numerous thin coats as opposed to one thick coat of paint. 

And remember: patience pays off. Don’t rush the drying process between coats.

How to Paint French Doors Without Taping

French doors are notoriously time consuming to paint, especially when you have to tape around each of the glass panels.

Painting French doors without taping can be tricky, but it’s doable. The secret? Use a steady hand and a good quality angled brush. 

Paint as close to the glass panes as possible, and don’t worry too much if you get paint on the glass. If the paint you’ve used is water-based, you should be able to wipe it off with a damp cloth. A little more effort will be needed with oil and resin-based paints.

For clean edges, avoid overloading your brush with excess paint, and keep your strokes controlled. If you’re using a roller, choose a small one suited for tight spaces to avoid splatter.

How to Paint a Flat Door

Flat doors are easier than painting panelled doors, but you still need a good technique to get a neat finish because there’s no room for error with flush panel doors – consistency is incredibly important to get that smooth, professional look. 

Start by removing the door from its hinges for easier access and remove all hardware, door handles etc. Sand the door surface lightly, then apply a primer if necessary.

For large flat surfaces, use a paint roller or a paint spray gun for the bulk of the work and a brush for the edges. To avoid marks, apply the laying off technique – lightly roll over the wet paint to smooth it out. 

Two or three thin coats should give you a flawless finish.

Painting Doors Like a Pro

Painting internal doors, whether they’re solid wood or glazed, is a DIY project that, with the right approach, can deliver professional results without the professional price tag. 

Preparing your wooden doors for painting with proper sanding, priming, and applying the right wood painting techniques will set you up for success. 

Just remember to use the laying off painting technique for a smooth finish, and choose the best paint for wood depending on your needs. 

Follow these tips and we’re sure you’ll soon have your interior doors looking neat and fresh in no time, but if you think it might just be a little too much for you, our range of pre-finished and ready primed internal doors are always an option!