Grain Filler VS Sanding Sealer: What’s the Difference?


If you are a beginner woodworker, you may be wondering what the difference is between grain filler and sanding sealer. Both of these products are designed to improve the appearance of your woodworking projects, but they serve different purposes.

In this blog post, we will discuss the differences between these two, as well as when you should use each one.

What Is Grain Filler And What Does It Do?

Grain filler is a woodworking product that’s used to fill in the pores of the wood. By filling in these pores, you’re able to achieve a much smoother finish. 

It is applied on top of open-grained woods, such as oak, mahogany, and walnut. This will help to create a smooth surface for paint, varnish, or stain.

When Should You Use Grain Filler?

Grain filler should be used when you want to achieve a completely smooth surface. This is because grain filler will fill in the pores of the wood, creating an even surface. Grain filler is also ideal for use on open-grain woods, such as oak and mahogany.

Grain filler can be applied after staining, or sometimes after a light sealer coat. Once applied, the surface is sealed and can be finished smoothly.

If you are working with a closed-grain wood, such as cherry or maple, you may not need to use a grain filler. Using grain filler on closed-grain woods can sometimes result in an uneven surface.

What Is Sanding Sealer And What Does It Do?

If you’ve ever tackled a refinishing project, you know there’s a lot of sanding involved. Once the old paint or stain is removed and the surface is smooth, it’s time to apply a sanding sealer.

A sanding sealer is a clear film-forming material that seals the pores of bare wood and provides a smooth surface for finish coats. It’s applied before the final stain or topcoat.

One of the main functions of a sanding sealer is to prevent grain raise or the lifting of wood fibers when a finish is applied. Sanding sealer provides a barrier that prevents finishes from penetrating too deeply and raising the grain by sealing the pores.

Another benefit of using a sanding sealer is that it dries very quickly. This is important because it allows you to get on with the finishing process sooner rather than later.

Finally, sanding sealer gives you a smooth surface to work with when applying your finish. This is especially important if you are planning on staining the wood, as a smooth surface will ensure an even finish.

When Should You Use a Sanding Sealer?

You should use a sanding sealer after sanding the wood to bare finish. You can do this before applying the topcoat. This will help to even out the surface and provide a better foundation for the topcoat. It is important to note that holes and imperfections in the wood will not be filled in by a sanding sealer, so it is important to do any necessary repairs before applying the sealer.

If you are working with a piece of furniture that has already been painted or stained, you will need to remove all of the old finish before applying sanding sealer. Once the old finish has been removed, you can sand down the wood surface to prepare it for the sealer. Be sure to sand in the same direction as the grain of the wood to avoid creating scratches.

Once you have applied the sanding sealer, you will need to wait for it to dry completely before moving on to the next step. Depending on the temperature and humidity levels in your workspace, this could take anywhere from a few hours to a day. Once the sealer is dry, you can begin applying the topcoat.

What Is The Difference Between Sanding Sealer And Grain Filler?

There are key differences between the two that you should be aware of as you choose the right product for your woodworking project. 

Grain filler and sanding sealer are both used to fill in imperfections in woodworking projects, but they serve different purposes.

  • Grain filler is used to fill in the pores of the wood so that it can be sanded smooth. This gives the wood a more consistent look and feel.
  • Sanding sealer is used to seal the wood and prevent it from soaking up stain or paint. This gives the wood a more uniform appearance.

So, there you have the key differences between these two sealers. Be sure to choose the right product for your project, depending on the look you’re going for.

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Do You Stain Before Grain Filler?

No, you should stain after applying grain filler. This will help ensure an even finish. If you stain before applying grain filler, you may find it difficult to achieve an even coat. In addition, staining after grain filler gives you the opportunity to touch up any areas that may have been missed.

Once you’ve applied grain filler and allowed it to dry, you’re ready to sand. Begin with a coarse-grit sandpaper and work your way up to a finer grit. Sanding will help smooth out the surface and prepare it for staining.

When you’re ready to stain, start with a light coat. Allow the stain to dry completely before applying a second coat, if necessary. Remember, it’s always easier to add more stain than it is to remove it.

Once you’re satisfied with the color, you can move on to sealing. A good sealer will protect your wood from moisture and wear, and help ensure a long-lasting finish.

Do You Sand Sanding Sealer?

Yes, you always sand sanding sealer after drying. This is because sanding sealer contains a high concentration of solids that will not fully cure without sanding. This will seal the wood pores which help improve the condition of each coat.

One advantage of sanding sealer is that it dries very quickly, usually in about 15 minutes. This means you can get on with your project faster than if you were using grain filler. Grain filler takes much longer to dry, sometimes as long as 2-4 hours before applying water-based finishes, and 24 hours before applying nitrocellulose.

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Kevin Nelson

I will always have a special place in my heart for woodworking. I have such fond memories working on projects with my parents on the weekends in the garage growing up. We built tables, shelves, a backyard shed, 10' base for a water slide into the pool, 2 story fort playhouse with a fire pole, and so much more. This woodworking blog allows me to write helpful articles so others can enjoy woodworking as much as we have.

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