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 stained wood, but you can’t leave it as the final coat. You must always apply a sealer or topcoat over as sanding sealer isn’t designed to be the final coat.
Wood stain must dry for at least 4 hours before you apply sanding sealer over it. If you apply it too soon, the whole finish will turn sticky.
Does Sanding Sealer Adhere Over Wood Stain?
Sanding sealer does adhere over wood stain because it has a formula that helps it to stick to every type of surface.
Sanding sealer is designed to adhere to poor surfaces, so it will stick well regardless of the surface type. Also, wood stain doesn’t have a finish that repels it.
However, the sanding sealer doesn’t stick well to oil-based wood stain as it has a glossy finish that is difficult to stick to. You must lightly sand the oil-based wood stain with fine-grit sandpaper before applying the sanding sealer.
Should You Apply Sanding Sealer Before or After Stain?
Sanding sealer is designed to be applied before applying wood stain as it helps it to adhere better by removing imperfections from the surface.
The purpose of sanding sealer is to help wood stain (or other types of finishes) stick on rough, porous, or uneven surfaces. It seals porous wood and prevents over-absorption.
You must use it on bare wood, especially if the surface has patches, large pores, or imperfections. Two (2) coats of sanding sealer will smooth the surface and create a base coat for additional coats.
You can also apply sanding sealer over stained wood, but only if you are planning to seal or paint over it. Sanding sealer isn’t designed to be the final coating as it doesn’t have a protective layer. It is designed to be applied between coats.
Don’t use sanding sealer before applying oil-based wood stain as it will prevent it from penetrating the surface pores. Oil-based wood stain is thicker and needs more space to penetrate.
How To Apply Sanding Sealer Over Stain?
To apply sanding sealer over stain, do the following things.
- Inspect the Finish.
- Sand the Existing Finish.
- Apply the Sanding Sealer.
- Scuff the Sanding Sealer.
Here are a few tips you must remember before doing this.
- Don’t use sanding sealer as the final coating.
- Wait until the finish is dry enough.
- Don’t apply a sanding sealer over an oil-based wood stain without sanding.
- Avoid using sanding sealer if you are planning to apply penetrating wood oil over it.
The tools you need for this project are listed below.
- Fine-grit sandpaper
- Clean rags
- A pair of work gloves
- A petroleum-based solvent like mineral spirits
1. Inspect the Finish
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
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
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
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.
How Long Must Wood Stain Dry Before Sanding Sealer?
Wood stain must 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.
The exact dry time depends on the type of stain, room temperature, thickness of the coat, and humidity levels. But, 4 hours is more than enough for most types of wood stains.
For the stain to dry, its solvent (water or oil) must evaporate from the coating.
If you apply sanding sealer before the wood stain dries, the finish will turn sticky as none of the finishes will dry properly. The new coating will prevent the solvent of the old coating from evaporating, so the whole finish will remain wet.
Can You Stain Over Sanding Sealer?
You can stain over sanding sealer, but it’s recommended to use gel stain over it. Water-based wood stain also sticks over sanding sealer, but oil-based wood stain doesn’t.
Oil-based wood stain is thicker and needs more space to penetrate the surface pores. Since the sanding sealer will fill most of the surface pores, the oil-based stain doesn’t have enough space to penetrate and won’t stick.
On the other hand, topical stains (such as gel stains) don’t need to penetrate a surface to stick, so they will stick regardless.
Can You Mix Wood Stain with Sanding Sealer?
You can’t mix wood stain with sanding sealer as they have different formulas and ingredients that aren’t compatible.
Both finishes have different purposes. Wood stain is designed to penetrate the surface and change (alter) its color while sanding sealers are designed to create a base coat and prevent over-absorption.