Wet Sanding vs Dry Sanding (When to Use Each)

Updated on January 11, 2023

Sanding things is often one of the most crucial steps in producing or adding finishing touches to an object. It is a process by which a surface is ground or polished with an abrasive material to shape, polish, and buff it. 

Sandpaper is one of the most widely used abrasive materials for sanding. Today we’re going to discuss two methods of sanding, wet sanding and dry sanding, and help you better understand the two processes. 

Let’s begin our take on the age-old debate between wet sanding vs dry sanding.

What Is Wet Sanding?

wet sanding

Wet sanding, on the other hand, is the process of sanding that involves a lubricant, usually water.  High-grit special sandpaper is used to perform wet sanding. 

Wet sanding is often done after dry sanding, as it is done to add finishing touches to a surface. For instance, after dry sanding a surface, it is wet sanded to make the surface smooth, glossy, and reflective. It gives surfaces a perfect look that looks professional and removes small imperfections and scratches.

When and Why to Use Wet Sanding?

Wet sanding is used to:

  • Smooth out objects and surfaces
  • Make anything exceptionally smooth
  • Get rid of cracks and or dents
  • Remove imperfections
  • Get rid of blemishes
  • Make surfaces glossy and reflective
  • Add a professional look to the end product
  • Reduce mess and dust
  • Remove deep scratches

Wet Sanding Best Use Cases

  • To make objects shine
  • To make surfaces ready for polishing and buffing
  • For drywalls
  • Metalwork
  • Glass work
  • Automobiles
  • Removing paint
  • Ceramic or porcelain work
  • Floors

Things To Consider About Wet Sanding

  • Too much sanding can cause surfaces to crack or weaken
  • Over-sanding can result in an uneven surface
  • Never sand one spot too much 
  • Takes a long time to complete
  • Maintain straight strokes 
  • The abrasive material that you use (not all abrasive material can be used for wet sanding)
  • The choice of lubricants

What Is Dry Sanding?

dry sanding

Simply put, dry sanding is a method of sanding that does not include a lubricant. Sandpaper of various grits is used to accomplish this. Different grits offer different kinds of usage. 

For instance, lower-grit sandpapers are used to shape and remove imperfections and to create an even surface. On the other hand, higher-grit sandpapers are used to smooth out and polish surfaces after sanding with low-grit sandpapers.

See Also: How to Correctly Sand Concrete

When and Why to Use Dry Sanding?

Dry sanding is used to:

  • Shape objects
  • Sand off edges
  • Get rid of cracks and or dents
  • Smooth out surfaces
  • Grind down surfaces and objects
  • Prevent wood from drying out

Dry Sanding Best Use Cases

  • Carpentry and woodwork
  • Sculpting
  • Painting 
  • Tiling
  • Removing paint
  • Evening out surfaces
  • Removing rust
  • Removing dirt

Things To Consider About Dry Sanding:

  • It tends to create a huge mess
  • Too much sanding can cause surfaces to crack or weaken
  • Over-sanding can result in an uneven surface
  • Never sand one spot too much 
  • Maintain small circular motions
  • Sand the surface evenly and equally
  • Take not of the grit of the sandpaper or type of sander

Difference Between Wet Sanding and Dry Sanding

Wet SandingDry Sanding
Makes surfaces extremely smoothSmooths out rough surfaces
Process takes a long timeProcess takes less time
Less messVery messy
Requires high grit sandpaperRequires low to medium grit sandpaper
Requires a lubricantDoes not require any lubricants
Done manuallyCan be done manually or with power tools
Removes a thin layer of materialCan remove large amounts of material
Requires movement in straight lines in both directionsRequires small circular motions or in straight lines

In the end, the difference between wet sanding and dry sanding comes down to purpose and intention. Because even though the working principle between the two is similar, the functionality they provide is vastly different. 

Dry sanding often does most of the work and is often a precursor to wet sanding, as wet sanding is more focused on further improving the output of dry sanding.

If you have read this far, you should now have a better understanding of the difference between wet sanding vs. dry sanding. Both of these methods are important and necessary. Often, you need to use both in succession to get the best results!

FAQs

wet sanding plastic

What Is a Lubricant When It Comes to Sanding?

A lubricant is a substance used to reduce friction between two surfaces. In the world of sanding, lubricants like plain water or soapy water are used to reduce the friction between the abrasive material’s surface and the object’s surface. 

This results in a much better finish and a smoother and more polished surface than dry sanding.

What Do You Mean By Grit?

Grit is a number given to sandpaper and abrasive objects. It is used to represent the size of the abrasive materials.

The higher the grit number is, the smaller or finer the abrasive is. Similarly, lower numbers mean the abrasive is coarser and bigger in size.

What Is Sandpaper?

Sandpaper is one of the most widely used abrasives by professionals across different industries. 

Sandpaper is coated abrasive, meaning it has abrasive material on one side. They are available in multiple grits, meaning they can be super fine to coarse.

Why Do People Wet Wood Before Sanding Them?

People wet wood to get a better and smoother end surface. 

When wood is wet or its surface is allowed to absorb moisture, the grains of the wood expand and grow bigger in size temporarily. So when wet wood is sanded, it becomes easier to grind and sand the enlarged wood grains. This results in a smooth and even finish.

However, once you are done sanding it, you should be careful not to get it wet again because if it gets wet again, it will undo all the sanding you did previously.

Can I Get Rid of Deep Scratches By Sanding?

Yes, you can definitely get rid of deep scratches through sanding! That’s because sanding allows you to grind down imperfections and make them more presentable. Just keep in mind that very deep scratches will require a lot of material to be removed to make the surface smooth.

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