how to clean walls before painting

Sanding Walls Before Painting [Step by Step Guide]

When you want to handle a painting job, it can be really tempting to get the job done as soon as possible. However, doing a good job should supersede hurrying the job at the expense of quality service.

Thus, preparing and cleaning the wall in advance before painting may save you from much stress and enable you to do a perfect job.

Why should you consider sanding walls before painting? Here are some of the benefits of the preparatory work:

At the end of this post, you’ll also learn how to clean walls before painting.

Why Sanding Walls Before Painting is Important

how to clean walls before painting

1. It makes your job cleaner

If the surface is rough or dirty, it will be a bit difficult to do a clean job without taking the time out to get rid of the rough or dirty surface.

When you sand the wall and remove such a problem, you will eventually get a clean surface after the painting. Otherwise, if you just apply the paint without removing the rough surface, you can imagine the result.

2. It reduces the painting cost

A dirty and rough surface will need more layers of paint to cover the defect. This will automatically increase the quantity and cost of the paint needed for the job.

If you want to cut the cost down a bit, removing the defect before applying the paint will be of help. That will save costs.

You are good to go after getting rid of any defect that may have a negative impact on your job. You should aim for the best and that includes getting the wall in good shape before you do the painting.

Tools Needed For The Job

Without the right tools to handle the sanding, it will be difficult to properly get it done. Having the right tools will increase your chances of doing a good job without spending unnecessary time trying to make do with what you have.

Your toolbox should include the following:

  • A small paintbrush that will be useful for dampening cracks in the surface prior to filling the cracks.
  • Sponge for cleaning necessary surfaces prior to painting.
  • Bucket: You need this to make the cleaning solution and paint.
  • Sanding block.
  • Scraper or filling knife to get rid of small bumps in the wall.
  • Dusters for cleaning the wall.

Materials needed

The materials you need for the sanding and prepping are:

  • A basecoat for a damaged or stained surface
  • Medium sandpaper: You need this as well. Since there are different types of this material, check the packaging for any indication that it is suitable for plastered surfaces
  • Plaster sealant is a necessity for freshly plastered walls
  • Retractable knife
  • Filler for filling cracks and holes in the wall
  • Masking tape

Safety tools

You should make your safety a priority while working. For your own safety, you need the following tools:

  • Safety goggles to protect your face and eyes
  • Rubber gloves to protect your hands against exposure to harmful chemicals while working

How to Clean Wall Before Painting | Necessary Preparations

sanding walls before painting

The prepping process should be done in the right way if you wish to get the best result for your efforts. Here is  how to clean walls before painting in order to get your walls in the best shape before you embark on painting it:

  • If possible, remove the entire furniture from the room. If that is not possible, find a way to protect everything in the room, including fittings and fixtures before painting
  • There may be issues of paint splatters; it is advisable that you wear clothes and safety goggles
  • Dust the walls and clean them as well. You can do this with a vacuum cleaner or a towel
  • If there are cracks and holes, fill them until the walls are smooth to give you the best finish
  • If there are surfaces that haven’t been previously painted or stained surfaces, prime them beforehand
  • Protect wall trim and sconces with painters tape before painting
  • If you see flaking or cracked painting, get rid of it with your paint scraper. Other imperfections such as plaster bumps may be smoothened with sandpaper

You can do the sanding in four stages:

Stage 1:

Dust the walls, skirting boards, ceiling, window frames, coving, and other fixtures thoroughly. To make it easier for you to reach some difficult-to-reach places, use a long-handled dusting want. If you have a ladder, you may use that as well.

Stage 2:

Get a bucket and prepare a sugar soap solution in it. Check the packaging for the instructions.

Stage 3:

With a large sponge, work on the surface by applying the mixture to wherever you want to work on. It is important that you wear rubber gloves while using the solution because the solution can irritate your skin.

After adding the solution to the appropriate places, leave it to work on the surface for a couple of minutes.

Stage 4:

When you are done with the solution, refill the bucket with clean water. Then use a cloth or a sponge to clean the surfaces with the clean water. While at it, make sure that the water is not allowed to drip down the wall while working.

Your prepping process should include the points mentioned above. By covering defective surfaces, you will make the painting easier and have a good finish.

Otherwise, your best efforts at covering the defects with more layers of paint may not give you the best result.

This is the best way to clean the wall before repainting. On the other hand, sanding a wall is a bit different, although it serves the same purpose: getting the surface into the perfect shape before repainting.

Step 1:

Get a sanding block and a piece of sandpaper (80 grit). Warp the sandpaper around the block and gradually sand one area of the room to another.

In a circular motion, ensure that the entire wall surface is covered. You can test the smoothness or roughness of the surface while working with your hand. This will ensure that the wall is evenly smooth.

If there are bumps or lumps, work on them until they give you a smooth surface as well.

Step 2:

Clean the surfaces from the ceiling to the floor by applying the suggested cleaning methods discussed above.

It is pretty clear that sanding walls before painting is quite beneficial. With the right tools and materials, you will get this done in no time and have great working experience while painting the wall.

Finally, watch the short youtube video below for a better understanding of how to sand walls before painting:

Do you need to sand walls before painting?

While sanding is not required for every paint project, rough spots on walls, whether they have been previously painted or not, need to be sanded before they are painted to ensure the paint goes on smoothly. For previously painted water-based paint, sand with a fine-grit sandpaper.

What happens if you don’t sand before painting?

Sanding also removes any bumps and impurities from the wood which would make it look uneven and messy. If you don’t sand before painting you will likely end up with an uneven finish and a paint job that will likely end up peeling after a few months.

What grit sandpaper should I use before painting walls?

Sand the filler smooth with 120-grit sandpaper. Prime the patched spots (or the whole wall if necessary). Sand primed areas with 120-grit sandpaper, and wipe clean of dust with a damp sponge.

Should I scrape my walls before painting?

No, you only need to scrape off old paint not properly adhering. Not all old paint. If any paint is flaking, curling up, this must all be removed, easiest way is scraping. Using a hand or powered tool, remove all this paint off of surface, before going any further.

What to do if you forgot to sand before painting?

Sand until everything is nice and smooth, checking for ridges or uneven parts. Wipe down the area well with a damp sponge, dry with a cloth and allow the area to dry. Then, you can prime and paint the patched areas. Be sure that the paint matches perfectly; otherwise, the repairs will look obvious.

How much should you sand before painting?

How Much To Sand Before Painting. Sanding a piece of furniture shouldn’t take more than 5 minutes. When you picture yourself sanding a furniture piece, you might envision yourself sanding away with a small piece of sander for hours to get every bit of old stain or paint.

Do you need to sand bare before painting?

It may seem unnecessary to sand bare wood before painting, but stock lumber is often coated in a glaze to help protect it. Removing that coating will help the paint adhere. In addition, sanding opens the grain of the wood, which can also help with adhesion.

Do professional painters wash walls before painting?

Do professional painters wash walls? Yes! For exterior painting, we usually power-wash the surface, or sometimes hand-scrub, to make sure it is free of surface contaminants. Inside, pressure washing is not an option, but in many cases the walls need to be washed prior to paint application.

What is the best type of sander for sanding walls?

Sandpaper, sanding block, or orbital wood sanders

Sandpaper is ideal for small projects, and you can have a sanding block to hold it down. Meanwhile, a random orbital sander is for ease when smoothing the wall. Sanding plaster walls with it can give the surface a cleaner and flatter finish.

How do you clean walls before painting after sanding?

Wet a cloth with water and squeeze it out until it is almost dry. Wipe down all of the drywall starting from the top. Drywall must be dust-free before painting, as the dust forms a thin film that may cause the paint to flake from the drywall surface. The wet cloth may dampen the drywall surface.

What happens if you don’t clean walls before painting?

You can paint over a dirty, glossy, chipping, and flaking surface, but don’t expect your handiwork to hold up over time. For new paint to stick, your interior or exterior surface needs to be clean and free of dust that could interfere with your paint’s ability to adhere to walls, trim, and ceilings.

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