Wet Sanding vs Dry Sanding: Know the Pros and Cons

Sanding is an important step in the refinishing process. You can choose to wet sand or dry sand your project, but which one should you use? Both methods have their pros and cons, so it’s important for users to know what they need in order to make an informed decision. Take a look at our blog post on wet sanding vs dry sanding here!

Table of Contents

  • What is Wet Sanding?
  • What is Dry Sanding?
  • Wet vs Dry Sanding:
  • How to Dry Wet Sand?
  • Can You Use Same Sandpaper for Wet and Dry Sanding?

What is Wet Sanding?

When the sanding purpose is more like delivering a mirror-like finish on the surface, one would initially choose the wet sanding. It is to shave off the microscopic layer of the paint surface with the help of water and abrasive pads or sandpapers.

Did you know that it is also called color sanding? It’s because while sanding, the color of the paint gets a reflection on the water.

What is Dry Sanding?

We recommend dry sanding in terms of shaping a surface. Dry sanding is the prior step of wet sanding. Therefore, the wet sanding is delivered to give a final smoothing effect by removing the huge scratches left by dry sanding. 

Dry sanding is used with the help of dry sandpaper. Wet sandpaper needs a continuous supply of water, while dry sandpaper doesn’t require any.

Are you done knowing the initial details about wet and dry sanding? Now let’s jump into some critical difference between these two methods of sanding.

Wet vs Dry Sanding:

There is difference between wet and dry sanding. These are discussed below on the basis of seven issues:

1. Difference in terms of the purposes

You would initiate dry sanding to shape the surface to give less sharp edges, usually on wood. Plus, it makes the design of the woods more detailed.

The wet sanding comes after the dry sanding. Did you know that wet sanding works best to remove large scarps left behind from the dry sanding? The mirror-like finishing is only possible after the step of wet sanding.

You can also use wet sanding as the paint correction for vehicles like smoothing the peeling, small runs, etc.

2. Difference in terms of using water

The word ‘wet’ will instantly suggest to you the fact that water or something liquid is involved in the wet sanding process.

Usually, liquids or lubrication like oil, water, or dish wash soap liquid are used to sand the surface. The continuous splash of water is needed in wet sanding, while the dry sanding is a withering process.

The dry sanding is likely to leave significant marks as you are not going to use water while sanding. So the wet sanding involves liquids to smooth out the finishing.

3. Difference in terms of using sandpapers

If you think you can use the same sandpaper for both of the methods, then you are very wrong there. The sandpaper you are going to use in wet sanding should just be made for it.

In hardware stores, you can find dry and wet sandpapers.

For wet sanding, you can make a thicker piece of sandpaper by folding it or by using a backing pad.

Also, you might want to check some sanding sponges available in shops. Remember that sponges are suitable for shaping the surface.

4. Difference in terms of movement

The movement you are going to make in wet and dry sanding will be different than each other. For example: In terms of dry sanding, you better move the sandpaper in a small circular motion.

On the other hand, for wet sanding sand in straight lines to alternating directions.

The circular motion of dry sanding smoothes out the surface, and the straight motion of wet sanding revives the stretches from previous passes.

5. Difference in terms of reducing dust

Wet sanding reduces dust more effectively than dry sanding. That is why the high-end-interior painters make use of wet sanding before they paint. Thus the sanding dust turns wet, and the paint doesn’t ruin.

6. Difference in terms of fine quality

When you desire fine quality finishing, there is nothing better than wet sanding. After all the mess with varnish, sealant, or polyurethane, we use a wet sander to give a final soothing touch.

The bumps and stretches you made from dry sanding can be reduced to nothingness with the help of wet sanding. Wet sanding is at its best when you use oil instead of water.

7. Difference in terms of appropriateness

To put it simply, dry sanding is appropriate for large wooden areas, such as wooden floors, decks, or walls. Usually, dry sanding follows the use of mechanical sander.

Wet sanding, on the flip side, is used for paint jobs and other delicate polishing. It is used by hand or manually.

Editor’s Tips

How to Dry Wet Sand?

If you don’t dry the wet sand in time, it might result in germs that are not so welcoming, right?

So you should dry out the wet sand as soon as possible, and for that, you may follow these easy ways:

  • Dry on sun
  • Dry in the oven
  • Dry using cement mixer

Dry on Sun

First, pick a sunny day to start the work and get a bucket of sand.

Now place the sand container in sunlight, it would be better if you put it under direct sunlight. Do not forget to leave the lid off the container.

For a quicker result, you can pour the sand in a large piece of cotton cloth or blanket. Use rocks or something weighty to hold the cloth so that it won’t blow away within the wind.

Stir the sand two or three times. It may take hours to dry out.

Dry in the Oven

Preheat the oven to 250 degrees F. Now, take a disposable baking dish and spread the sand.

Using a disposable dish is best as you might hesitate to use it for any other purpose. If you don’t have a disposable dish, you can also use any delicate baking tray.

Now set the tray in the oven for 30 to 45 minutes. Check after 30 minutes; if it’s still not dry, stir it and put it back for 15 minutes more.

Dry Using Cement Mixer

First, pour the sand into a mixer. Place a bucket underneath so that the sand doesn’t fall out. 

Use a propane torch or any other heat source to heat the sand. Turn the switch on; it may take around 30minutes to heat off the sands—Check-in between if it’s dry enough.

Secrets!

Can You Use Same Sandpaper for Wet and Dry Sanding?

To tell you the truth, you cannot work with the same sandpapers for different methods. For wet sanding, it is better to choose 3M’s “Wetordy” sanding paper. You can just find it in local stores or online purchasing sites. To make the sandpaper work better, you need to fold the sandpaper to make a thicker consistency. Alternatively, you can also warp the sandpaper around any backing pad.

For alternative ways, you can buy sand sponges too. The abrasive effect of the sponge may just work like wonder for you; it stands well with the different shapes of your materials.

And for dry sanding, you should use sandpaper of 120 to 180 grit (rough sanding for pulling out scratches), or 240 to 400 grit (for lighter sanding).

Final Words

To put it shortly, I would say that wet sanding is for the automotive refinishing application, while dry sanding is for woodworking or drywall. In this battle of wet sanding vs dry sanding, you must not argue which one is better, because in terms of sanding both of them are necessary suiting different purposes.

Although when it comes to sand metal directly, you may choose wet sanding. And in this case, use WD-40 instead of water. It shall help the paper to wet thoroughly.

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