Staining dry wood is easy. But, can you stain wet wood?
You shouldn’t apply stain over wet wood because it won’t stick since there’s a high level of wood tannins, oils, and moisture on the surface. The high level of moisture makes it impossible for the stain to penetrate and stick.
Oil-based stain especially doesn’t stick to wet surfaces because the moisture will repel the oils. However, some water-based stains can be applied over damp wood, but the results won’t be as smooth or colorful as if the surface was dry.
Why Doesn’t Stain Stick To Wet Wood?
Stain doesn’t stick to wet surfaces because they contain a large deposit of oils and tannins. If the wood was recently washed, there would also be moisture (or water) in it. All these substances make it very difficult for the stain to stick.
For the stain to stick, it needs to penetrate the grain through the pores. But, if the pores and grain are already filled with water or moisture, the stain won’t be able to penetrate and stick.
Stain soaks into the wood grain and changes its color. While paint stays at the top and only changes the color of the top layers. But, since the wood grain is filled with water, wood stains can’t penetrate the wood pores and won’t stick well.
Oil-based stains especially don’t stick well because they use oil (natural or synthetic) as their solvent, and oil isn’t compatible with water.
What Happens If You Stain It:
Here’s what happens if you do it:
Difficulty in Prepping It
You must prep the surface before staining it. The prep work involves cleaning and sanding the surface, but you can only clean and sand dry surfaces.
If the wood is wet, you can’t clean it because the rag will be filled with wood oils. Also, you can’t sand it because the sandpaper will get clogged up. This makes prepping the surface difficult.
Because of the high amount of moisture and dirt, the stain won’t stick.
Tannins, oils, and moisture in the wet surface will bleed through once the stain gets dry. This will make the finish appear blotchy as the color will be uneven. When this happens, you may also notice yellowing in the finish.
Longer Dry Time
The stain will take longer to dry because of the moisture in the surface. For a finish to dry, the solvent has to completely evaporate from the coating. But, since there’s moisture in the surface, the solvent takes longer to evaporate, which increases the drying time of the coating.
Tacky or Sticky Finish
The finish will turn sticky or tacky since it won’t dry properly. Bleed-through, poor adhesion and tacky finish mostly happen when you apply oil-based stain over it. Water-based stains perform better than oil-based stains on damp wood, but the result will still be inferior.
Wood Dry Time
On average, you should wait at least 24 hours for the wood to dry before applying a stain. Large surfaces like walkways, patios, and decks should dry for 3 days. This gives the surface enough time to dry so the wood pores can absorb a new finish.
However, the exact time to wait for it to dry depends on the type of wood, and how much moisture is inside the pores. and the ambient temperature. For example, hardwood is porous and absorbs more moisture than other types, so it takes longer for it to dry.
The more absorbent the wood is, the more moisture it absorbs and the longer it will take to dry. Popular types of hardwood include Oak, Maple, and Pine. Softwood will dry quicker and can be stained within 24 hours since the grain isn’t as absorbent as hardwood.
To know if the wood is dry enough:
- Feels Dry – If the surface feels dry and hard, then it has properly dried and you can stain it. However, if the surface feels wet and moist, it hasn’t dried yet.
- Raised Fibers – Moisture tends to raise wood fibers causing splinters in the surface after it has dried. So if you can spot splinters in the wood, the surface has dried enough. If the surface is still wet, the splinters won’t appear.
- Moisture Levels – Use a moisture tester to measure how much moisture is inside the surface. If the moisture levels are lower than 15%, the surface is dry enough. If the moisture levels are high than 15%, the surface hasn’t dried yet. You can also weigh the wood as it dries. The lighter it gets, the lower the moisture content is.
- Sand– When you can sand it smoothly without the sandpaper getting stuck, the surface is dry enough.
Types of Stain To Use
You should only use water-based stains over wet surfaces. They perform better because they are dissolved in water. So the coating is more compatible with moisture.
Some deck stains also work on damp surfaces because they are usually formulated to be moisture-resistant, so they will stick.
However, the finish you will get from applying stain over a damp surface will be inferior to the finish you’ll get if the surface was dry.
How To Stain Wet Wood?
Staining over damp wood is easy, but the task can be time-consuming and messy due to the moisture content in the wood. So you’ll need the following tools and supplies to make this task less messy:
- A hairdryer
- Fine-grit sandpaper
- Stain-blocking primer
- Water-based stain
- A paintbrush or spray gun
- Drop sheets
- Waterproof sandpaper
- A pair of gloves
1. Prep The Work Area
You must prep the work area to avoid mess. Place a large drop sheet on the floor around the wet wood to do this. The sheet will help to collect tannins and filth that fall off the wood.
As a part of prep work, you can wet-sanding the wood. Dry-sanding can’t be done on wet wood, but wet-sanding will help make the wet wood smoother. You’ll need waterproof sandpaper for wet sanding.
2. Dry The Wood
To speed up the wood drying time, increase the ambient temperature around the wet wood. You can use a hairdryer for this. Turn on the hairdryer and move it over the wet wood to increase evaporation.
You can also expose the dry wood to sunlight. So if you can, move the wood outdoors. The increased heat, exposure to sunlight, and dry air will make the wood dry faster.
3. Apply Stain-Blocking Primer
When the wood has dried a bit, apply a stain-blocking primer over it. Stain-blocking primers, such as shellac primers, are designed to prevent moisture from affecting the coating.
To apply it, use a paintbrush and apply 2-3 coats.
4. Scuff The Primer Coating
When the primer coat dries, scuff it with fine-grit sandpaper. The sandpaper will smoothen the primer coating and create tiny scars for the new to penetrate to.
After sanding, remove dust nibs from the surface so they don’t create bumps in the finish.
5. Apply The Water-Based Stain
Apply water-based stain over damp wood using a paintbrush or sprayer. After applying it, use a hairdryer to help the coating dry faster and properly. Then, wait 24-48 hours until the coating dries before sealing it.
How Do You Know If Wood Is Dry Enough To Stain?
How Long After Rain Can You Stain Wood?
You should wait at least 3 days after rainfall before you stain a wet wood or deck. Especially, if the wood doesn’t have any moisture-resistant layer on it.
If there is a moisture-resistant layer on the wood, let the wood dry for 24 hours. The moisture-resistant layer prevents the wood grain from absorbing high moisture content. So the wood will dry faster and can be stained sooner.
Overall, you can stain over damp deck or wood using water-based stain only. However, you must try to dry the wooden surface as much as possible first.
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,