MDF wood has a porous surface with large pores, so can you stain it?
You can stain MDF wood because it has a porous surface and will absorb stains. However, you must prep it to prevent over-absorption and help the material absorb stain evenly.
To prep, sand the MDF board with 150-grit sandpaper, fill the gaps with wood filler, and apply a thin layer of shellac-based washcoat. After the washcoat dries, sand it with 400-grit sandpaper and apply wood stain.
Types of Stains to Use:
You can use different types of stains on MDF surfaces, but the best one is an oil-based stain. That’s because it has better wood penetration, and its thick flow won’t penetrate the material too deep. This includes varnish, lacquer, gel stain, and other stains dissolved in oils (solvents).
Avoid using water-based stain because MDF is sensitive to moisture which causes it to swell. Water-based stain uses water as its solvent, and if the wood absorbs too much of it, the solvent (water) will cause the wood to swell.
Painting vs Staining (For MDF)
When finishing MDF, you can either paint or stain it. But, what’s the difference?
Wood stain enhances the wood color and allows the grain to show because it penetrates the surface deeply. On the other hand, paint covers the wood grain because it stays over the top layer and doesn’t penetrate the material deeply.
Here are more differences:
You can use different types of paints on MDF, but 0il-based is better for this material. Oil-based paints are thicker and provide a glossy layer over the surface, protecting it from moisture, water, and other damage.
Paint doesn’t penetrate a surface deep to stick (compared to wood stain); instead, it produces a layer over the top layer that covers (hides) the surfaces underneath. This means the wood grain will be covered by paint. You can choose different colors and mix two colors (of the same type of paint) to get a unique color.
You don’t need to seal paint for indoor MDF wood, as the paint’s glossy finish will protect it. However, if the wood is placed outdoors, you must seal it with a waterproof sealant.
- Protect the surface from scratches and dent marks.
- It’s available in different sheens.
- Protects the surface from moisture and spills (to a degree).
- Dries fast.
- For indoor surfaces, you don’t have to seal it.
- Hides imperfections.
- You must apply a primer before painting.
- You must thin it.
Staining will enhance the MDF wood color, but won’t protect it. That’s because the wood stain is made 60% from pigments and wood dye, meaning it doesn’t have protective additives and is formulated to only give color to a surface. That’s why it’s mostly used over decorative surfaces.
Wood stain penetrates the wood deep to stick, meaning it doesn’t stay over the top layer as paints do. However, since MDF surfaces have large pores and are porous, you must seal them to prevent over-absorption. You can seal it by using a washcoat or sanding sealer.
- It provides a colorful finish.
- It’s easy to apply and doesn’t require thinking.
- You can mix different types to create a unique finish.
- You don’t need to apply a primer.
- It highlights curves and shapes on the surface.
- It’s difficult to remove as it penetrates the surface deeply.
- You must seal it.
- It doesn’t offer wood protection since it’s not waterproof or resistant.
So, should you stain or paint MDF? Well, the answer to that ultimately depends on your taste and needs. If you want a protective finish, use paint, as they are stronger and able to withstand more use.
On the other hand, stains must be used on decorative MDF only. Remember to seal the wood stain so it becomes durable, especially for outdoor surfaces.
How To Stain MDF Cabinets, Doors, and Stairs?
Staining MDF surfaces isn’t difficult, but you must prep (seal) it to prevent over-absorption and help the surface absorb stain evenly. You can do it by applying a coat of sanding sealer or shellac-based washcoat.
Here are the tools you need:
- Lint-free cloths
- A gallon or more of oil-based wood stain (pick the right color)
- Oil-based polyurethane
- Mineral spirits
- A vacuum
- Shellac-based washcoat
- Drop sheets
- Sandpaper of different grits
- Paint stripper (if there is an existing finish on the MDF)
- A power sander (for large MDF surfaces)
1. Strip The Existing Finish
If an existing finish is on the MDF board, the wood stain will not stick and will peel off in a few weeks. So, you must strip (remove) it.
To remove an existing finish:
- Apply paint stripper over the surface.
- Wait 15-30 minutes.
- Scrape the finish using a paint scraper.
- Clean the surface with water and leave it to dry.
2. Sand The MDF
Sanding will remove imperfections, dust, and filth from the surface. Start by sanding with 100-grit sandpaper and finish with 220-grit sandpaper by working your way up. After sanding, remove the dust.
To prevent over-absorption, fill the pores of the MDF board with sanding dust. To do so, sand the surface with 320-grit sandpaper and use the dust produced to fill the pores.
3. Apply Washcoat
To prevent a patchy or splotchy finish and help the surface absorb stain evenly, apply a shellac-based washcoat. You can use sanding sealer or wood conditioner as an alternative to a washcoat.
4. Apply Wood Stain
To stain MDF:
- Use a chip or bristled paintbrush or a rag.
- Apply 2-3 coats of oil-based stain.
- Wait until one coat dries before applying the next one.
On average, it takes wood stain 1-2 hours to dry enough for a re-coat. If the wood stain is too thick, thin it with mineral spirits in a ratio of 1:2 (1 part mineral spirits to 2 parts of wood stain).
After it dries, seal the finish with polyurethane or spar varnish to increase its durability and make it water-resistant. Apply 3 coats of sealant over the finish and wait 3 days for it to dry before using.
Changing Its Color
To change the color of MDF furniture, use wood paint or wood stain. However, wood stain gives more color. On the other hand, paints give more sheen.
You can also change the MDF color or add color to it using wood dye or paint powder. These products can be mixed with mineral spirits, linseed oil, paint thinner, and other oil-based solvents. You can apply the mixture to the surface, and the color will set on the surface when the solvent dries.
In summary, you can apply stain over MDF wood since it has a porous surface with large pores. But, you must prep the surface to prevent over-absorption and help it absorb stains evenly. To do so, apply a shellac-based washcoat, sanding sealer, or wood conditioner.
After applying 2-3 coats of wood stain over MDF, leave the finish to dry before sealing it with a waterproof sealant.
Tony is a professional painter and an author of DIY Geeks. Tony has completed over 1,000 painting projects for his clients. It's safe to say he knows what he Is talking about,