Can You Use Sanding Sealer Over Stain? (& Vice Versa)

Sanding sealer is often a shellac or lacquer formula applied over uneven wood before a top coat. But, can you put sanding sealer over wood stain?

You can apply sanding sealer over the stain, but you can’t use it as the final coat. You must always apply a sealant or topcoat over it.

It’s also recommended to sand it before sealing it. This removes blemishes and imperfections in the coating.

Compatibility

Sanding sealer sticks over wood stains because it has a formula that allows it to stick to every type of surface.

Since it is designed to be used on poor surfaces, the sealer is formulated to adhere well regardless of surface type. Plus, wood stains don’t have any ingredients that will repel it.

However, sanding sealers might not stick well to oil-based stains because they have a glossy sheen that prevents anything from sticking over them. The texture of the glossy sheen is slick and difficult to stick to.

So, to put sanding sealer over an oil-based stain (or paint), you must sand the glossy layer off. 

Sanding Sealer Before or After Stain?

Do You Use a Sanding Sealer Before or After Stain?

Sanding sealers are designed to be used before applying stains as it helps them to stick better by removing imperfections from the wood. 

The sanding sealer purpose is to help wood stain (or other paints) stick to rough, porous, and uneven surfaces. It seals porous wood and prevents over-absorption. 

The sanding sealer should be used on bare wood. For instance, if the surface has patches or large pores, apply two coats of sanding sealer, and the sealer will make the wood smoother and ready to accept stains. 

You can also apply it over stained wood, but you must seal it or paint over it. Sanding sealer shouldn’t be the final layer. You can also apply it between coats if you want to apply multiple coats of topical stains.

You shouldn’t use sanding sealer before applying regular penetrating stain, such as oil-based stain. That’s because it will prevent the oil-based stain from penetrating the wood. If the oil-based stain can’t penetrate the wood, it won’t stick and will peel off after a while. 

How To Apply Sanding Sealer Over Stain?

Applying sanding sealer isn’t hard; this guide will show you how to do that in just 4 simple steps. However, there are certain rules and conditions you should remember before embarking on this task:

  1. Never use it as the final coat.
  2. The finish should be dry enough for recoat before applying it.
  3. Don’t apply sanding sealer over oil-based stain unless you remove their glossy sheen first.
  4. Never use sanding sealer if you would be putting penetrating wood oil over it.

Here are the tools you need:

  • Fine-grit sandpaper
  • Clean rags
  • Paintbrushes
  • A pair of work gloves
  • A petroleum-based solvent like mineral spirits

1. Inspect The Finish

Check If The Existing Stain Is Dry

The stain must be dry before you apply sanding sealer over it. If it isn’t dry, the sanding sealer won’t stick, and the finish will turn sticky.

To know if the stain is dry enough, swipe 320-grit sandpaper over the coating. If the sandpaper doesn’t move freely, the finish isn’t dry enough. If the sandpaper moves freely, the finish is dry enough.

If you don’t have sandpaper, wait at least 4 hours for the finish to dry.

2. Sand The Existing Finish

Sand The Existing Stain

To sand stain, use fine-grit sandpaper. The sandpaper will remove bumps and imperfections from the coating. It also created ridges in the coating that the sanding sealer can bite into to stick better. However, you shouldn’t sand too hard because you can remove the coating completely. 

After sanding, remove the dust using a clean rag. 

3. Apply The Sanding Sealer

Apply The Sanding Sealer

Next, apply the sanding sealer. To apply it, use a paintbrush and apply thin coats. You must cover the surface evenly so the new stain can be absorbed evenly. 

Apply one coat of sanding sealer if you don’t want to switch the color of the existing finish. Apply two coats if you want to switch the color or sheen.

For instance, if you want to move from a dark finish to a light one, you can apply two coats of sanding sealer on the dark stain to prevent the dark shade from affecting the new light coating.

4.  Scuff The Sanding Sealer

Scuff The Sanding Sealer

Sanding sealer takes one hour to dry. Once it dries, scuff or sand it. Sanding removes blemishes and tiny imperfections from the sanding sealer. These imperfections can prevent the new stain from sticking well.

If you don’t sand it, the imperfections will prevent the new coating from sticking well. And, these blemishes will show through if you use a clear coat. 

To sand sanding sealer, use 200-grit sandpaper. You shouldn’t use coarse or medium-grit sandpaper as it can remove the entire coating.

Stain Dry Time Before Sanding Sealer

Stain should dry for 4 hours before putting sanding sealer over it. After the coating dries, it will be hardened enough to support a new coating over it.

However, its dry time depends on the type of stain and drying conditions. But, 4 hours is more than enough for most types. For the stain to dry, its solvent (water or oil) must evaporate from the coating. 

If you apply it too soon, the stain won’t dry properly and will turn sticky. That’s because the new coating will prevent the solvent from evaporating, so the coating will remain wet for longer. 

Can You Stain Over Sanding Sealer?

You can only apply topical stains over the sanding sealer. You shouldn’t apply penetrating wood stain as they won’t stick. 

Regular wood stains are penetrating finishes and won’t stick to the sanding sealer. That’s because they need to penetrate the wood pores to stick, but since the sanding sealer will seal wood pores, the stain won’t be able to penetrate the already-filled wood pores. 

However, water-based stains and clear coats can stick over sanding sealer because they don’t need to penetrate wood as deeply. But, you must sand the surface before applying them. 

On the other hand, topical stains, such as gel stains, don’t need to penetrate the wood pores to stick.

Mixing Them

You shouldn’t mix sanding sealer with stain. That’s because they have different formulas and ingredients that aren’t compatible. 

Also, both products have different functions. Stains are designed to penetrate the wood and change the color of the wood grain. Sanding sealers are designed to prevent penetration, so mixing both products means that they will get in each other’s way.

Final Words

You can use sanding sealer over stain, but you shouldn’t use it as the final coating. That’s because the sanding sealer isn’t strong enough to protect the surface from different elements. You must always apply a topcoat over it. 

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