You can apply Tung oil over regular wood stain, but the finish must be dry and you must apply thin coats. You can’t apply Tung oil over penetrating stains such as gel or lacquer stains as they don’t allow penetration.
To apply Tung oil over wood stain, clean the finish, sand the finish, and apply the Tung oil.
Note: Tung oil sticks better to oil-based wood stains as they use the same solvent (oil).
Does Tung Oil Adhere Over Wood Stain?
Tung oil adheres over a regular wood stain finish if sand lightly the finish first. Tung oil doesn’t adhere to topical or sealed wood stains as they have a moisture-resistant topcoat that prevents Tung oil from penetrating the coating.
Since Tung oil needs to penetrate a surface to stick but it can’t penetrate a sealer topcoat, the wood oil won’t stick unless you remove the sealer.
You must apply thin coats of Tung oil over the wood stain for it to stick. If you apply thick coats, the wood oil won’t stick as it won’t be able to soak into the wood pores (which are already filled with wood stains).
To improve the adhesion of Tung oil and wood stain, sand the surface with fine-grit sandpaper. Sanding will create tiny pores (holes) that the wood oil will penetrate into, and remove parts of the finish making penetrating easier.
How To Apply Tung Oil Over Wood Stain?
To apply Tung oil over wood stain, do the following things.
- Clean the Finish.
- Sand the Finish.
- Apply the Tung Oil.
The tools you need for this project are listed below.
- Fine-grit sandpaper
- A degreaser
- An angled paintbrush
- Clean lint-free rags
- Tung oil
1. Clean the Finish
Clean the wood stain finish with a degreaser to remove dust, dirt, grease, and debris that can prevent the Tung oil from adhering.
If the stained wood is sealed, use coarse-grit sandpaper (40-grit) or paint-stripping paste to remove the sealer top coat.
2. Sand the Finish
Sand the stained wood with fine-grit sandpaper (220-grit) to remove surface imperfections and bumps, and create tiny pores (holes) that the Tung oil can penetrate and adhere to.
Don’t use coarse or medium-grit sandpaper as it can remove the wood stain finish from the surface. Ensure to clean the surface after sanding with a damp rag to remove the dust.
3. Apply the Tung Oil
Apply three (3) Tung oil coats over the wood stain finish using a lint-free rag. Rub the wood oil over the surface using circular motions. Wait until one Tung oil coat dries, wipe the excess, and apply the next coat. Use an angled paintbrush to cover tight spots and corners of the wood.
Seal the Tung oil finish with polyurethane or varnish to increase its durability and protect it from water, moisture, scratches, or weather elements.
Does Tung Oil Darken Wood Stain?
Tung oil doesn’t darken wood stain, it only makes its color appear deeper. Since the Tung oil finish is thick and reflects low light, the color of the wood stain will appear darker. But, if you remove the Tung oil the natural color of the wood stain returns.
The Tung oil finish will develop an amber (gold-like) color shade because of the high amount of wood oils in its formula. This happens once the wood oil cures (fully dries).
To prevent an amber (gold-like) color shade, thin the Tung oil with mineral spirits (up to 50%) before applying it. This makes its flow (coating) lighter, so it doesn’t deepen the color of the wood stain and makes it easier to apply.
Which Types of Wood Stain Can You Apply Tung Oil Over?
The types of wood stain you can apply Tung oil over are listed below.
1. Water-based & Oil-based Wood Stain
You can apply Tung oil over a water-based stain, but the coating must be fully dry. Optionally, you must sand the coating to improve the adhesion.
You can also apply it over oil-based stain because it has a high volume of tree oil, so it’s compatible with Tung oil.
However, you must sand off (remove) the glossy layer of oil-based stain to allow the Tung to penetrate. If you don’t, the glossy layer will prevent the wood oil from penetrating its coating, and the wood oil won’t stick.
Which Types of Stain You Can’t Apply Tung Oil Over?
1. Minwax Stain
You can’t apply Tung oil over the Minwax stain. That’s because Minwax stain is also a penetrating oil finish and will fill the wood pores. So, if you apply Tung oil over it, the wood oil won’t be able to penetrate and won’t stick.
2. Gel Stain
You can’t apply Tung oil over Gel stain. That’s because Gel stain is a penetrating finish that can’t be painted over. When dry, it forms a moisture-resistant coating that repels liquid, including wood oil.
