The Art Of Skim Coating: Mastering The Perfect Pullover Finish

Skim coating is a cost-effective way to smooth out your walls and make the interior of your home look new again. It involves applying a thin layer of joint compound or plaster to your walls to fill in any low areas of texture and create a glass-smooth finish. The process is fairly straightforward, but it can be labour-intensive and messy, so make sure you prep your space beforehand by covering any furniture and floors with plastic sheets. You'll also need a paint roller, a drywall knife, and a joint compound to get started.

Prepping the walls

Before you start skim coating, it's important to prep your space. Cover the floors, furniture, and appliances to protect them from drywall dust. Seal off the room to contain the dust. Remove baseboards, outlet and switch covers, and tape off all outlets to keep them free of drywall cement. Cover the floors with plastic if necessary, especially if you have carpet.

Next, you'll need to prepare the wall by cleaning it thoroughly and removing any loose or peeling paint. If there are any holes or cracks in the wall, fill them in with joint compound and let them dry completely. Knock down any peaks or high areas on the wall texture using a 6-inch taping knife.

Before skim coating, it's essential to prime the wall. Apply one to two thin coats of an appropriate primer to the wall and wait for it to dry thoroughly. This step will seal any loose paper on the drywall and ensure better adhesion of the joint compound.

Mixing the joint compound

The joint compound, also known as "mud," should be mixed to a thin, workable consistency, similar to the consistency of yogurt or thick pancake batter. It should be thin enough to smooth onto the wall but not so thin that it drips or dribbles down the wall. You can use a paddle mixer and drill attachment to mix the compound in a bucket, adding small amounts of water gradually until you achieve the desired consistency. Make sure to remove any lumps from the mixture.

Applying the joint compound

Start by rolling the joint compound onto the wall using a thick-nap paint roller. Work in small sections, such as 2' x 2' or 4' x 4' squares, to prevent the compound from drying too quickly. Apply a generous amount of mud to the wall, using a roller to speed up the process.

Skimming the walls

After applying the joint compound, use a trowel, such as a Magic Trowel, to smooth out the compound. Hold the trowel at a slight angle and pull it in one direction, either upward or downward, to smooth out the compound. Apply slightly more pressure to one side of the trowel to create a low ridge on the other side. Overlap each pass to ensure a smooth finish. The first coat may not be perfectly smooth, and you may need to apply additional coats to fill in heavy textures. Alternate the direction of each consecutive coat for a smoother finish.

Mixing the joint compound

Step 1: Choose the Right Joint Compound

Select a lightweight, all-purpose joint compound. This type of compound is easier to sand smooth and serves almost no structural purpose, so you don't need a heavy-body compound.

Step 2: Gather Your Materials

You will need a bucket, an electric drill with a paint paddle attachment, and water. You may also want a large spoon or similar utensil for mixing.

Step 3: Prepare the Joint Compound

Before you begin, make sure you know the mix ratio specified in the product instructions. This will guide how much water you need to add.

Step 4: Mix the Joint Compound

Start by pouring the joint compound into the bucket. Slowly add water, using an electric drill with a paint paddle attachment to mix the compound. Gradually add water until the mixture is smooth and free of lumps. Aim for a yogurt-like or mayonnaise-like consistency. Be careful not to mix it too thin, as this can cause shrinkage.

Step 5: Adjust the Consistency

If you find that your mixture is too thick, you can slowly add small amounts of water and continue mixing until you achieve the desired consistency.

Step 6: Work in Small Batches

It's best to mix the joint compound in small batches, as it can start to dry out in the bucket before you have a chance to apply it. Check the drying time on the packaging so you know how long you have to work with the mixture.

Step 7: Use it or Store it

Once your joint compound is mixed to the correct consistency, you can either use it immediately or store it for later. If you plan to store it, make sure to cover the bucket to prevent drying.

Remember to always follow the specific instructions provided by the manufacturer of your chosen joint compound, as different products may have unique requirements.

Applying the compound to the wall

Applying the joint compound to the wall is a messy process, so make sure to cover your floors, furniture, and appliances. Seal off the room to contain the dust. Remove baseboards, outlet and switch covers, and tape off all outlets to keep them cement-free.

When you're ready to begin, use a paint roller to apply a generous amount of mud to the wall, working in small sections at a time. Using a roller will allow you to apply the compound more quickly than if you were using a putty knife. You can pour the compound into a roller tray or dip the roller directly into the bucket.

After applying the compound to a section of the wall, use a trowel or drywall knife to smooth it out. The first coat won't be perfectly smooth, and you may need to apply more layers if you have a heavy texture on your walls. Each coat of mud should be smoothed in the same direction it was applied. Alternate directions with each consecutive coat.

Keep the surface consistently wet by misting the edges of the area you just smoothed before starting a new section. Slightly overlap the previous section as you roll the next one.

Tips

• Use a damp rag or spray bottle to wet the blade before use.
• Pull the trowel or knife over the compound, smoothing it in the same direction that you applied it with the roller.
• If you have a heavy texture on your walls, the first coat may not produce perfectly smooth results. Don't worry—the next coat will fix any gouges or new lines.
• Shine a light at an angle on the wall you're working on to better identify imperfections.

Smoothing the compound with a knife

Firstly, it's important to use the correct type of knife. A drywall knife, also known as a taping knife, is the best tool for the job. For skim coating walls, a 12-inch knife is recommended, although smaller sizes such as 6-inch and 9-inch knives can also be useful for knocking down peaks and high areas on the texture. You may also want to use a squeegee knife, which is a wider tool (around 14 inches) that can speed up the process and help you achieve a flatter, smoother finish.

Before you start smoothing, it's a good idea to have some rags and a mud pan or tray handy. This will allow you to wipe the blade of your knife after every few strokes and remove any excess compound that builds up.

Now, you can begin smoothing the compound. Start at the top corner of the section you're working on and hold the knife so that its left side is slightly closer to the wall than its right side. Pull the knife straight down, applying slightly more pressure to the left side. This will help ease out any imperfections on the left while leaving a low ridge on the right. Be careful not to exert too much force, as this may result in removing too much compound or even gouging the wall.

Overlap each vertical pass with the knife until you finish the section. You may need to go over some areas a few times to get a smooth finish. Once you've completed the top section, move on to the lower half and smooth it by pulling the knife upward.

If you're using a squeegee knife, you may need to go over the compound a few times to get the hang of using the tool. Don't worry if the first coat isn't perfectly smooth; the compound is filling in the voids around the raised surfaces in the existing texture. Each coat of compound should be smoothed in the same direction as it was applied.

Remember to alternate directions with each consecutive coat. If you applied the compound vertically on the first coat, switch to a horizontal application for the next coat. This will help you achieve an even finish.

By following these steps and taking your time, you'll be able to achieve a smooth and professional-looking finish on your skim-coated walls.

Sanding the walls

Prepare the Walls:

Before starting the sanding process, it is crucial to prepare the walls by addressing any imperfections. Fill in any holes, cracks, or nicks in the wall with spackle and allow it to dry completely. If there are larger holes, apply a drywall patch for a proper repair. Additionally, if the wall has glossy paint, use 220-grit sandpaper to lightly scuff up the surface and remove the sheen. This step is essential to ensure the skim coat adheres properly to the wall.

Clean the Walls:

Once the repairs are dry, thoroughly clean the walls to remove any dust, residue, or grime. Use a damp sponge or towel and, if needed, a commercial surface-cleaning product. Rinse the wall with clean water after using any cleaning products. A clean surface is crucial for the skim coat to adhere properly.

Sand the Walls:

After the wall is prepared and cleaned, it's time to sand it. Use 220-grit sandpaper to run over any rough patches or raised edges on the wall, smoothing them out. Shine a light from the side to better identify any low or raised spots that need attention. Wear a face mask and protective eyewear during this step to avoid inhaling dust or irritating your eyes.

Apply a Skim Coat:

Once the wall is sanded and you've achieved a smooth surface, it's time to apply the skim coat. Mix the joint compound with water to achieve a yogurt-like consistency, following the specific instructions on the product you're using. Apply the compound to a section of the wall with a roller or a drywall knife, and then smooth it out with a drywall knife. Work in small sections and let the compound dry before moving on to the next step.

Sand Again if Needed:

Depending on the condition of your walls, you may need to repeat the sanding process after the first skim coat. This helps to smooth out any remaining imperfections and prepare the wall for additional coats of the joint compound. Remember to wear protective gear during this step as well.

Apply Additional Coats:

If necessary, apply a second layer of the joint compound in the opposite direction of the first coat. This helps ensure even coverage. Continue adding new coats until your wall looks smooth, lightly sanding with 220-grit sandpaper before each coat. Remember to let each coat dry thoroughly before applying the next layer.

By following these steps and taking your time, you'll achieve a professional-looking skim coat that transforms the look of your walls.

Frequently asked questions