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Wooden surfaces are often sealed with polyurethane to protect them from the elements and extend their lifespan. In this blog post, we will discuss how to seal wood with polyurethane and how to choose the right one for your needs.
There are many types of polyurethane sealants on the market, so it can be difficult to decide which is right for your project. They include water-based, oil-based, and solvent-based polyurethanes. If you want to seal a piece of wood furniture for an interior space, you should use water-based polyurethane. However, if you want to seal wood with polyurethane for outdoor piece of furniture or something exposed to lots of wear and tear, you should use an oil-based polyurethane.
What Is A Polyurethane Sealant?
Polyurethane sealant is a type of sealant that is made from two components: polyol and isocyanate. The polyol component can be either water-based or solvent-based, while the isocyanate component will always be solvent-based.
Polyurethane sealants are available in both gun grade and sausage grade. The two components are mixed and then applied to the surface that needs to be sealed. The sealant will form a film on the surface, which will harden over time, protecting water and other elements.
Polyurethane sealants are ideal for sealing wood as they provide good protection against moisture and also help to protect the wood from rot and decay.
Types of Polyurethane Sealants
There are three main polyurethane sealants: solvent, water, and oil.
1. Solvent-Based Polyurethane
Solvent-based polyurethanes are the most popular type of sealant. They come in a variety of finishes, including glossy and matte. They are also the most durable type of sealant.
However, they can harm your health if you breathe in the fumes, so it’s important to use them in a well-ventilated area.
Advantages:
- Durable
- Many finishes available
- It can be used on a variety of surfaces
Disadvantages:
- Harmful fumes
- Not water resistant
- Can yellow over time
The two most popular types of solvent-based polyurethane are oil-based and latex. Latex is more environmentally friendly because it doesn’t contain any harmful solvents. However, it’s not as durable as oil-based polyurethane.
Also Check: How to Spray Polyurethane For a Beautiful, Protective Finish
2. Water-Based Polyurethane
Water-based polyurethanes are environmentally friendly and low in odor.
They are also the most versatile type of polyurethane because they can be used on interior and exterior wood surfaces.
Advantages:
- Versatile
- Low odor
- Environmentally friendly
Disadvantages:
- Not as durable as oil-based polyurethanes
- It may cause the wood to swell and buckle if applied too thickly
- Can yellow over time if applied to light-colored woods
3. Oil-Based Polyurethane
Oil-based polyurethanes are best for exterior use because they have a high solids content and excellent weathering characteristics.
They also form a harder film than water-based products, which makes them more resistant to abrasion.
However, these products tend to be smelly and can cause skin irritation. They should also not be used on floors because they can create a slip hazard.
Advantages:
- High solids content
- Excellent weathering characteristics
- Harder film than water-based products
Disadvantages:
- Smelly
- Cause skin irritation
- If put on floors, they can create a slip hazard.
Which Polyurethane to Seal Wood With
When deciding which type of polyurethane to seal the wood, you need to consider the project’s location, the type of wood, and how much durability you need.
If you seal an exterior surface exposed to the weather, then an oil-based polyurethane is a better option because it is more durable.
Water-based polyurethane is a better option if you are sealing a piece of furniture or an interior surface because it is more versatile and environmentally friendly.
However, if you seal a light-colored wood, be aware that the water-based polyurethane may be yellow over time.
Related Post: Satin vs Semi Gloss Polyurethane Finish —How Do They Differ?
How To Seal Wood With Polyurethane In 6 Steps
Once you have chosen the right type of polyurethane, it is important to follow the manufacturer’s instructions on how to apply it.
Tools Required:
- Paintbrush or roller
- Bucket
- Stir stick
The following are step-by-step instructions on how to apply a polyurethane sealant to wood.
Step 1: Clean The Surface
The surface should be clean and free of dirt, dust, and grease. If it is not, the polyurethane will not adhere to the wood properly.
Step 2: Sand The Surface
If the surface is rough, you will need to sand it until it is smooth. Be sure to use sandpaper appropriate for the type of wood you are using.
Step 3: Apply The Primer
If the surface is not primed, you must apply a primer before applying the polyurethane. The primer should be specifically designed for use with polyurethanes.
Step 4: Apply The Polyurethane
Once the surface is primed and sanded, you can apply the polyurethane. Be sure to use a brush or roller appropriate for the type of polyurethane you use.
Step 5: Let It Dry
Once you apply the polyurethane, let it dry according to the manufacturer’s instructions. Then you can apply a second coat, if necessary.
Step 6: Seal The Wood
Once the polyurethane is dry, you can seal the wood with a coat of wax or paint. This will protect the polyurethane from fading and chipping.
Related Post: The Best Exterior Polyurethane: How to Choose The Right One For Your Home
FAQs
How Long Does It Take for Water-Based Polyurethane to Dry?
It usually takes about 24 hours for water-based polyurethane to dry. However, it is important to follow the manufacturer’s instructions for how long to let it dry.
What Is the Best Way to Apply Polyurethane?
The best way to apply polyurethane is with a brush or roller. Be sure to use one that is specifically designed for the type of polyurethane you are using.
How Long Does Polyurethane Last?
Polyurethane can last many years if properly applied and taken care of. However, it is important to follow the manufacturer’s instructions for how long it will last.
What Is the Difference Between Water-Based and Oil-Based Polyurethane?
Water-based polyurethane is more versatile and environmentally friendly. However, it may be yellow over time. Oil-based polyurethane is more durable. But it is smelly and can cause skin irritation. So, you need to decide which one to use based on the project’s location, the type of wood, and how much durability you need.
How Do I Remove Polyurethane from My Hands?
If you get polyurethane on your hands, you can remove it with a solvent such as paint thinner or mineral spirits. Be sure to follow the manufacturer’s instructions for how to remove it.
What Are the Safety Precautions When Using Polyurethane?
When using polyurethane, be sure to follow the manufacturer’s instructions for safety precautions. You should wear gloves and a respirator to avoid skin irritation and fumes. You should also work in a well-ventilated area.
If you are using oil-based polyurethane, be sure to use a solvent such as paint thinner or mineral spirits to remove it from your hands. And always follow the manufacturer’s instructions for how to apply and remove it properly.
How Do I Clean Up Polyurethane?
Clean up any polyurethane that is spilled immediately. It will be very difficult to remove if it is left to dry. You can use a solvent such as paint thinner or mineral spirits to remove it.
How Do I Know Which Type of Polyurethane to Use?
You should consider the project’s location, the type of wood, and how much durability you need.
If you are sealing an exterior surface exposed to the weather, then an oil-based polyurethane is a better option because it is more durable.
If you are sealing a piece of furniture or an interior surface, a water-based polyurethane is a better option because it is more versatile and environmentally friendly.
However, if you are sealing a light-colored wood, be aware that the water-based polyurethane may be yellow over time.
Conclusion
When deciding which type of polyurethane to use, you need to consider the project’s location, the type of wood, and how much durability you need.
If you are sealing an exterior surface, then an oil-based polyurethane is a better option because it is more durable.
If you are sealing a piece of furniture or an interior surface, then a water-based polyurethane is a better option because it is more versatile and environmentally friendly.
However, if you are sealing a light-colored wood, be aware that the water-based polyurethane may be yellow over time.
Happy Sealing!
Also Read: Types of Sealants Used in Construction
