December 29, 2022

Dry sanding vs Wet sanding | Which Method is Right for Your Project?

This post discusses the pros and cons of dry sanding versus wet sanding. If you’re a woodworker, painter, or DIY enthusiast, you’ve probably come across both sanding methods at some point. But which one is the best choice for your project? In this post, we’ll be taking a closer look at dry sanding and wet sanding to help you understand the differences between the two and when to use each one. By the end of this post, you should have a good understanding of the benefits and drawbacks of both methods, and be able to choose the one that’s right for your project. So let’s dive in and get started!

Dry sanding

Dry sanding removes more material and smooths rough material quickly. Dry sanding evens out a surface, such as on wood, to make edges less sharp or to make woodworking more detailed.

Dry sanding is a way of sanding and finishing a wood project. It is for polishing and smothering the surface of the wood. The process helps get rid of tool marks on your project. That way, you can bring out the smaller details in the project.

When dry sanding a project, move from coarse grit sandpaper to finer grit options. Grits are in numbers (Thespruce.com). The bigger the number, the coarser the grit. Before sanding, clean your piece, removing any dust, debris, or sawdust.

Please fold the paper you are using, so it becomes big enough to hold with three fingers. Larger ones become difficult to control. You can use a wood piece or a rubber sanding block to make it easier to hold onto the sandpaper. There is no need to have this extra aid since chances are low that the sandpaper can be slippery to try and hold onto directly. 

All you need to do is rub the sandpaper in small circles in the direction of the grain. Dry sanding can be done either by hand, using sandpaper or a sanding stone, or power tools like belt sanders and disc sanders. However, there is a specific method using a power sander. Hand sanding is for smaller pieces, whilst heavy-duty power sanders are for carpentry work.

Pros

  • Smooth finish
  • It removes small imperfections.
  • High-quality
  • Faster 
  • Detailed

Cons

  • More sawdust build-up
  • Navigating sandpaper grits can be challenging

Wet sanding 

Wet sanding uses water to act as a lubricant. It is less abrasive than dry sanding and gives a smoother finish. It is ideal to wet sand at the end of a project. That is after you have already applied the finish and want to smooth out any brushstrokes.

If you want a smooth finish, avoid wet sanding bare wood because you do not want a smooth finish yet. It makes the wood more difficult to stain. If you intend to take off a fair amount of wood, avoid wet sanding since it takes time.

Wet sanding involves removing the large abrasions left by dry sanding. Wet sanding will level out a surface, and abrasions left behind will become smaller and less visible. The result is a mirror-like finish that makes scratches invisible.

Wet sanding uses a liquid or some other lubrication, such as oil, to help remove small particles. Failure to use water as a lubricant makes the grit build up in the sandpaper and leaves behind large abrasions. These can ruin the finish. Dish soap with water can work as a better agent in wet sanding.

Wet sanding is used in home interior jobs, and reduces dust. High-end interior painters use wet sanding before painting and between coats. The sanding dust gets wet and does not ruin the paint. The sandpaper for wet sanding lasts longer, but keep rinsing it with water. Wet sanding also reduces dust when installing sheetrock. 

Pros

  • Detailed
  • High-quality
  • Effective at removing paint and coatings 
  • Less dust
  • Even finish

Cons

  • Needs different sandpaper
  • Cannot use power tools

Features of Dry sanding

Movement 

The movement used in dry sanding is different from wet sanding. Dry sanding requires small circles to get an even finish, while wet sanding uses straight lines and alternating directions between passes. The reason for this is to remove scratches from previous passes. Use a light touch with wet sanding since you will remove the surface scratches and not a lot of material.

Sandpaper 

Dry sanding involves several rounds of sanding. Start with the coarsest grit sandpaper you have chosen and make your way up to using the finest grit you have available. That is around 320 grit, but you can go as high as 800.

Grit

Dry sandpaper should never be used for wet sanding, as the abrasive grit on sandpaper stays in place with non-waterproof glue. That may result in the grit being released from the paper. 

Features of Wet sanding

Sandpaper

You cannot use the same paper you use for dry sanding on wet sanding. The sandpaper you use for wet sanding should be made for it. There are wet or dry sandpapers available in hardware stores. To make a thicker piece, you can fold the paper twice and use a backing pad. There are abrasive sanding sponges attached to the pad to help the sanding surface follow the shape of the material.

Lubricant 

The water makes scratches less visible and gives better control for the uniform thickness of the finish. Using oil instead of water gives a satiny finish. You can also add a few drops of detergent to the water to make sanding easier. An alternative to water is mineral spirits. You can still use tap water for the same effect.

Movements

The movements for wet sanding are different from those for dry sanding. Wet sanding requires you to use straight lines, making sure to alternate directions between passes. That allows you to get rid of any fine scratches from dry sanding.

What could have been better

Dry sanding 

  • It could have been finer for a finish.
  • It could have been easier to know when to stop sanding.

Wet sanding 

  • There could be only one sanding style for ease of use.
  • Using power sanding tools could have been easier.

Similarities 

  • They both remove material to create a smoother surface.
  • They use sandpaper.
  • They use their hands. 

Differences between dry sanding and wet sanding

Wet SandingDry Sanding
Surface FinishSmootherMore abrasive
DustMinimalMore
TimeLongerQuicker
CloggingLessMore
Clean-upMoreLess
Sandpaper lifeLongerShorter
CostMoreLess
Health HazardLessMore
  • Wet sanding removes less material, whereas dry sanding removes more material.
  • Wet sanding uses lubricant, but no lubricant is required for dry sanding.
  • Wet sanding reduces mess, unlike dry sanding.
  • Wet sanding takes more time, whereas dry sanding takes less time.
  • Wet sanding uses higher-grit sandpaper, whereas dry sanding uses lower-grit sandpaper.
  • Wet sanding produces a super smooth finish, whilst dry sanding produces a smooth finish.
  • Wet sanding is done by hand, whereas dry sanding is done by hand or with the power tool.

The verdict 

In summation, choosing between the two depends on what you intend to use them. When you are looking for a super smooth finish, try wet sanding. It also works better when sanding is going to create a huge mess, and if you are willing to spend a long time sanding. If you have a lot of material to remove, then dry sanding might be a better choice. By now, you should have your best pick. 

David D. Hughes

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