Is it important to sand before painting?

Author: Marcel VonRueden  |  Last update: Thursday, November 27, 2025

To achieve a nice smooth finish, it's essential to sand to help prepare the area for painting application, by sanding you are removing imperfections (also known as pimples), creating a nice smooth finish while at the same time adding adhesion by developing small, rough ridges for the paint to stick to.

What happens if I don't sand before painting?

Sanding is often a crucial step for ensuring that your surface is ready to be painted. If you don't have a properly sanded surface, paint may not adhere to certain items properly. You can oversand, undersand and often people underestimate its importance. But, you don't have to be a pro to sand a surface.

Can I paint on paint without sanding?

Yes, you can paint right over old painted furniture without sanding. You will need something called a DEGLOSSER and you can use this on OLD KITCHEN CABINETS to prep for new paint as well! Find my favorite Deglosser HERE.

Can I just paint over old paint?

No, you can paint over old paint, providing it is in sound condition and not peeling. If there is peeling paint or a cracked surface you must address those issues by scraping, sanding, and priming before applying a top coat of paint.

Do professional painters sand walls before painting?

Yes, imo, all surfaces should at the very least be lightly sanded and cleaned before painting. This is one of the steps that separates pros from Diy'ers.

Why you need to sand walls before painting

Can you paint walls without sanding?

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.

Can I use Dawn to wash walls before painting?

“It's a good idea to dust the walls to remove any loose dirt or cobwebs. You can use a duster or a soft cloth for this step,” Carpenter suggests. Prepare the cleaning solution. Start by filling your bucket with warm water and adding the Dawn dish soap.

Do I need to sand off all the old paint before repainting?

Remember you do not need to remove all of the paint, just the damaged and flaking portions of it. Any paint that can just be peeled off needs to be removed as it is not bonded to the underlying layers sufficiently.

What happens if you don't use primer before painting?

Without primer, paint will absorb into the surface instead of forming a film on top. This can cause patchy, uneven color that requires even more coats of paint.

Can I paint straight over painted walls?

If the current wall is smooth, clean and covered with the same type of paint (both are oil-based for example), you can head straight for the paint.

What is an alternative to sanding?

Instead of sanding, use a liquid deglosser to dull the existing finish. This product helps you prepare the surface for new stain or paint without the need to strip or sand.

Why do painters sand before painting?

To achieve a nice smooth finish, it's essential to sand to help prepare the area for painting application, by sanding you are removing imperfections (also known as pimples), creating a nice smooth finish while at the same time adding adhesion by developing small, rough ridges for the paint to stick to.

What is a good bonding primer?

If you have various stains, shellac Bonding primer is the ideal choice. It can be used to cover rough surfaces and old varnish as well as metal and ceramic.

What paint do you not have to sand first?

Requiring no prep work at all, adhesive chalk paint is inherently kind of a miracle if you don't want to sand the surface first—it sticks to so many surfaces. And yes, as a bonus, you can use it as a chalkboard (this actually could be cool on a breakfast table that your kids will be sitting at, just saying).

Can you sand and paint the same day?

To sand properly, your coats of paint should dry a minimum of 24 hours, potentially extending your project out for a few days.

Does liquid sandpaper really work?

Liquid sandpaper is a chemical solution that removes the glossy layer from a painted item, enabling you to paint over the object without the paint dripping off. Unlike regular sandpaper, it just removes gloss; it can't be used to smooth the surface, correct imperfections or as a paint primer.

Do professional painters use primer?

In order to save time and money, professional painters recommend using a good primer.

What is better, eggshell or satin?

Of the two, satin is more durable and is slightly less likely to scuff or mark than eggshell and it's easier to clean when it does get marked. This makes it a better choice, especially for woodwork such as painting skirting boards, than eggshell for high traffic areas like hallways and living rooms.

Can I paint over primer without sanding?

Technically, yes, you can do that. Some circumstances don't require sanding the existing paint and primer before repainting. If you choose this route, the car's surface might show minimal damage like puncture holes, body scratches, dents, and cracks. The body will look smooth and mostly intact.

Can you just paint over existing paint?

As long as the underlying paint is sound, you can paint over it, but to achieve a professional result, you'll need to know the specific factors that will give you a high-quality paint job. Anyone who has painted a room knows that the end result depends on how carefully the walls were prepared before painting began.

What do professionals strip paint with?

Dimethyl sulfoxide (DMSO) has become more popular since it has a low level of toxicity, making it a safe replacement for methylene chloride and NMP. Opting for a safe active ingredient like DMSO or a manual paint stripping method will be far safer than risking NMP or methylene chloride.

Is it better to paint over or remove old paint?

Sanding and stripping off unwanted paint revives rooms and augments the authenticity of texture and appearance. Removing paint gives old surfaces a new look, making homes and objects feel fresh again.

Why don't professional painters wash walls before painting?

In most cases, professional painters don't wash walls with a detergent solution to avoid damaging the drywall or trim. Instead, most professional painters lightly sand or “scuff” the walls with a pole sander using fine-grit sandpaper.

What is the correct order to paint a room?

The Best Order to Paint a Room
  1. Ceilings. Paint a 2-inch wide strip on the ceiling where it meets the wall. ...
  2. Walls. Paint a 2-inch strip along ceiling, floor and woodwork with a brush. ...
  3. Woodwork. Paint all trim around doors, windows, ceilings and floor.
  4. Floor. Start in a corner diagonally opposite the room exit.

Why use TSP before painting?

When mixed with water to create an alkaline solution, TSP is a highly effective cleanser, degreaser, and stain remover. It's also used to prep painted surfaces for refinishing or repainting, as it can both de-gloss paint and remove flaking or peeling areas.

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