Polyurethane is usually applied with a paintbrush. But, using a paintbrush over a large surface is tedious and time-consuming. So, can you apply it with a roller?
You can apply polyurethane using a roller, but you must use a lambswool roller as it can absorb and apply the sealant smoothly. You can also use a foam roller, but never use it for water-based polyurethane.
Before using it, you must dip the roller into mineral spirits. This prevents it from absorbing too much sealant and prevents a bubbled finish.
Types of Polyurethane:
You can use foam, microfiber, and lambswool rollers to apply oil-based polyurethane. This sealant has a thick flow, so these rollers absorb it well.
Its thick flow also allows the roller to spread it smoothly and without marks. However, this type takes longer to dry, especially if applied with a roller.
You can use fiber and lambswool rollers for water-based polyurethane, but you can’t use a foam roller.
Since it has a lighter flow, you can only use specific rollers to apply it. For instance, foam rollers are porous and can absorb more water-based polyurethane than needed. This results in uneven coats. So, you shouldn’t use it.
However, fiber and lambswool rollers will spread it evenly.
Paint Roller Types:
The paint roller you use must be lint-free and absorb the sealant evenly. Also, it shouldn’t leave paint streaks behind.
Here are the types of rollers we recommend:
The foam rollers are designed using a commercial foam material. They have impressive absorption, making them ideal for absorbing and applying oil-based polyurethane.
However, they are not ideal for water-based polyurethane because they cause streaks and paint drops. Also, they aren’t durable.
Microfiber rollers are woven paint rollers wrapped with a layer of microfiber cloth. The cloth has short and small fibers causing it to apply multiple layers of polyurethane without streaks or marks.
It is great for water-based polyurethane because it is durable and can be used for multiple applications as long as it is well-maintained.
The lambswool roller is gotten from lamb wool. The wool is knitted together to prevent the layers from separating or pulling apart.
It has a synthetic backing that makes the paint application faster and easier. In addition, its soft nature makes it possible for it to fit in corners and release the sealant evenly. However, they are expensive.
Tip: To get the best finish possible, always buy high-quality rollers that are compatible with the type of polyurethane you will use.
Pros & Cons
- It saves you time as you cover more space faster.
- Doesn’t leave brush marks.
- It will give you a smooth finish.
- You can use the same roller to apply different types of polyurethane.
- Ideal for large walls and floors due to their quick application.
- They can’t apply the sealant on corners and curves, so you’ll still need a paintbrush for touch-ups.
- High-quality rollers are expensive.
- It increases the chances of paint bubbles.
- You must dip it into mineral spirits or turpentine.
How to Roll on Polyurethane?
Applying the sealant with a roller is an easy task. However, you need the right instruction and tools.
Here are the tools that you need for this task:
- Mineral spirits
- A clean paint bucket or plastic container
- Painters tape
- Lacquer thinner
1. Prep Work
First, prep the surface you will paint. If you want to paint a wall, remove all objects on the wall (wall sockets, photo frames, etc.). To paint a floor, remove all the furniture. If it’s a wooden surface, clean it.
Cover or tape objects with painter’s tape for objects you can’t move.
2. Sand the Surface
Sanding will remove imperfections and bumps from the surface, allowing the sealant to stick better.
If you apply polyurethane on a bare surface (such as wood), you need to sand the wood to remove loose dirt and bumps. To sand the wood, use 180-grit sandpaper.
Sanding will produce a lot of dust — so wipe the surface after sanding.
3. Apply the Polyurethane
To apply polyurethane with a roller, you must pour the sealant into a large clean bucket. Then, dip the roller into the bucket for a few seconds and take it off. Optionally, you can pour mineral spirits into the roller first before dipping it.
Here’s a step-by-step guide:
- Dip the roller into mineral spirits.
- Shake it to remove excess mineral spirits.
- Put it into the container and allow it to absorb the sealant.
- After a few seconds, take it out and apply the polyurethane.
Don’t press it into the surface as it can cause paint bubbles and streaks. Instead, move it back and forth until you apply all the sealant. Once you apply all the absorbed polyurethane, dip the roller into mineral spirits first, then dip it into the container again to absorb more.
5. Apply a Second Coat
When you apply the first coat, leave the polyurethane to dry for at least 3 hours before applying a recoat. While you wait for the sealant to dry, you must prevent the roller and sealant from drying up.
To prevent it from drying, put it into a plastic bag and then into a fridge. This prevents the roller from drying or turning sticky. Once you need a second coat, remove it from the fridge and re-use it.
Before applying the second coat, dip it into mineral spirits again. You need 2-3 coats of polyurethane for proper coverage.
How To Clean a Polyurethane Roller?
Here are the tools you need:
- Paint roller squeezer
- Mineral spirits
- Dish soap
- A bucket of warm water
- A metal comb
Here is how to do it:
- After applying the last coating of polyurethane, shake off the excess. You can also use a paint roller squeezer for this.
- Mix dish soap with warm water and soak the roller in the soap mixture.
- After a few minutes, remove it and wash off the residue.
- Dip it in mineral spirits and use a metal comb to clean and untangle it. This will also remove stuck polyurethane.
- When it is clean, rinse it in cold water and store it properly.
- If the roller isn’t completely clean, you can repeat the steps.
In summary, rolling on polyurethane is possible, but, you need the right type. For instance, use microfiber and lambswool roller for the water-based type and foam roller for the oil-based type.