Wet Sanding vs Dry Sanding – The Best Guide for DIYers

Wet sanding vs dry sanding, both have their uses when working with wood. But when is the right time to dry sand or wet sand a piece of wood you are working on? The short answer is that dry sanding is typically used with low-grit sanding paper to remove layers from wood surfaces. On the other hand, a wet sanding process is to finish a woodworking project with less abrasive, high-grit sandpaper. 

While it sounds straightforward, there is more to getting a good finish on bare wood than knowing the difference between wet sanding vs dry sanding process. 

This article is a guide to achieving a smooth finish on wooden surfaces. You will learn about essential techniques when using the wet sanding method and how to prepare wood surfaces using dry sandpaper.

What Is Wet Sanding?

Wet sanding involves applying a thin layer of water to the wood surface or fine-grit sandpaper to smooth out all imperfections. The combination of high-grit abrasive paper and water creates a smoother finish. Furthermore, it removes scores and scratches from the wood. In addition, the wet sand method ensures a mirror-like finish on the wood piece. 

Using water as a lubricant prevents fine sawdust from building up in the sandpaper. This process prevents the large particles from causing abrasions and ruining the finish. Apart from using water, you can also use a combination of dish soap and water for a smoother finish.

What’s the Advantage of Wet Sanding?

The primary advantage of using a wet sander is getting a super-smooth, scratch-free finish on the wood surface. Of course, wet sanding drywall and metal make it possible to get a superior finish. You will find that lacquer, varnish, paint, or wood stain looks better and shinier. 

Creating less dust is another advantage of using abrasive wet paper to finish wood surfaces. Especially in a home workshop, using the wet sand process stops dust particles from getting into the air.

This has two significant benefits.

·        First, you avoid breathing in potentially harmful dust.

·        Second, sanding dust doesn’t land on painted pieces as they are drying. 

Wet drywall sanding also significantly reduces the amount of dust from the drywall in the air. Therefore, you can help protect your lungs and skin from the harmful effects of inhaling drywall dust, whether from sanded wood, metal, or sheet-rock. 

Disadvantages of Wet Sanding

Wet sanding has no disadvantages if you want a scratch-free, smooth surface on a wood finish. However, it is vital to know that the wet sand method is more time-consuming than dry sanding bare wood. It also takes more care because you must sand along the grain and change the wet paper more often. 

When Would You Use Wet Sandpaper?

The wet sanding method is the best way to finish a wood project before applying stain or another protective layer.

Sometimes, abrasions or microscopic scratches after dry sanding are almost unnoticeable to the naked eye. However, they can become pronounced after the wood is stained, painted, or varnished. 

Of course, whether to wet or dry sand depends on the type of wood finish you intend to apply. For example, if you plan on painting a work-piece with primer and two coats of gloss paint, you may not need to use the wet sanding process. 

However, suppose you are making high-end furniture pieces or other wooden items that will be stained or finished with varnish. In that case, the wet sanding method is vital to ensure the best finish for your wood project.  

Do You Need Special Sandpaper for Wet Sanding?

When finishing a wood project with abrasive wet sandpaper, it is best to use special wet-dry sandpaper. This type of paper is specially made for applying a lubricant like water or a dish soap solution. There are various types of sandpaper suitable for applying water. These are the following:

·        High-grit sanding paper.

·        Use a sanding block with wet-dry sandpaper.

·        Use a sanding sponge specially designed for finishing wood. The wet sponge ensures the sanding surface follows the material’s shape. 

Before applying water to the wood surface or sandpaper, ensure it indicates it is for wet sanding. 

What Is Dry Sanding?

Dry sanding refers to the process of using abrasive paper to sand a surface without using moisture. This method is typically used to smooth large surfaces or remove an existing finish. When you dry sand a wood piece, you open the wood pores to allow it to absorb stain, varnish, or paint. 

Advantages of Dry Sanding

Compared to wet sanding, dry sanding has the advantage of removing more surface material. Starting with low-grit paper, the abrasive paper will quickly eliminate existing varnish, paint, or lacquer. Additionally, you can smooth any blemishes on the wood surface. 

In this respect, dry sanding is a vital element of any woodworking project.

Another advantage of dry sanding is using power tools to create a smooth surface. For example, belt sanders, orbital sanders, and drum sanders all use the dry sand method. This makes the process faster than wet sanding to achieve a smooth finish.

Disadvantages of Dry Standing

Although dry sanding is crucial to prepare and smoothing wood surfaces, it has drawbacks. For example, compared to the wet method, using dry sandpaper on wood creates large amounts of dust. In addition, while it is possible to use an electric sander with a vacuum, hand sanding creates sawdust. 

Another challenge when dry sanding is choosing the right sandpaper grits. Typically, you start with the lowest-grit sandpaper and then gradually move to paper with less abrasive grit.

It’s also good to know that you cannot achieve the same smooth finish with dry sanding as you can with wet sandpaper. Using regular sandpaper without moisture can end up fairly rough sanding, leaving behind surface scratches

When Do You Use Dry Sanding

You would use dry sanding whenever you want to prepare wood for staining, painting, or applying a finish. The goal of using dry sandpaper is to smooth out blemishes on the wood surface or remove an existing finish. Other reasons for the dry sand method include removing splinters, changing the shape of wood, or flattening an uneven surface.

In some cases, dry sanding is necessary to remove a layer of wood to make the piece smaller. This is often necessary for cabinet or furniture making. For example, dry sanding the edge of a door or drawer may be required to achieve a perfect fit.

In essence, dry sanding is the more aggressive sanding method. You typically use circular motions to remove a thin layer from the work-piece surface. Then, you would use finer grit dry sandpaper, sanding along the grain. Finally, in the final stages, you would use fine-grit wet sandpaper moving in straight lines to buff or polish the wooden item. 

Another time when dry sanding is vital is to sand surfaces between each coat of finish or stain. Sanding with high-grit sandpaper smooths out flaws or removes dust on the surface. This helps the final coat to appear blemish-free without any specks of dust or scratches.

What Is the Difference Between Wet Sanding vs Dry Sanding

Both dry sanding and wet sanding are necessary when working with wood. Using a piece of sandpaper is the only way to get a smooth finish on a wood surface. Additionally, wet and dry sanding will achieve a fantastic shine on the work-piece. However, not all wood surfaces require both methods. 

Here is a list of the differences between the two methods. 

Wet Sanding 

·        Removes less material from wood surfaces.

·        It uses a lubricant, typically water or water with a bit of detergent added.

·        Wet sanding eliminates excess dust.

·        You must use high-grit sandpaper that is made for wet sanding.

·        You can only wet sand by hand.

·        Special wet-dry sandpaper is necessary.

·        It takes lots of time, care, and attention to detail to wet sand the surface of the wood.

·        Wet sanding polishes and buffs surfaces rather than removing a layer. 

·        Wet sanding in a straight motion achieves the smoothest finish.

Dry Sanding

·        The best method for the removal of paint and previous finishes.

·        Gets rid of deep scratches and other blemishes.

·        Removes more material in each pass.

·        No lubricant is necessary.

·        Less time is required to achieve a smooth finish.

·        Uses low to high-grit abrasive paper.

·        You can use power tools to sand wood or do it by hand.

·        Dry sanding creates a significant mess with lots of sawdust.

Which Way Is the Best Way to Sand Wood

Sanding wood is a relatively easy process. First, choose the right grade of sandpaper and sand along the grain. Then scribble a light pencil line on the surface.

Next, take sandpaper with a higher grit and sand until the line disappears. Continue the process until you achieve the smoothness you require.

Although the process of sanding is straightforward, it takes time to master sanding skills to get a super smooth finish.

So, here are a few tips to sand wood like a pro.

·        Use a belt sander or orbital sander if you must remove a lot of paint.

·        After removing the previous finish, always sand with the wood grain if possible. This will help create a smoother finish. 

·        It’s fine to move up in grades from coarse to fine in larger increments. For example, for dry sanding, start with 80-grit paper, then move to 120-grit sandpaper, and finally, 220-grit sandpaper. Then finish with a couple of passes using wet sandpaper with super-fine grit.

·        Always keep surfaces clean using a vacuum. If possible, it’s worth investing in a sander with a shop vacuum attachment. 

·        Sand wood to the right depth, keeping in mind the type of wood. For example, closed-grain woods like cherry and maple can take sanding with a higher grit to eliminate scratches. On the other hand, open-grain woods like walnut and oak have a naturally rough texture, and sanding with fine grit sandpaper is unnecessary.

·        Remember that wet sanding is the preferred method to finish fine wood pieces. 

Conclusion — Wet Sanding vs Dry Sanding

Although both methods use sandpaper to produce a smooth finish on wood, wet and dry sanding are different processes. Wet sanding is the most effective method for finishing wood furniture. It requires a little more effort than just dry sanding; however, it produces beautiful results.

On the other hand, dry sanding is ideal for removing old finishes, eliminating scratch marks, and preparing a large surface area of wood for painting.