Can you polyurethane over polycrylic? This is a question that comes up often, and the short answer is no.
The reason for this is because of the different characteristics of each product. For example, Polycrylic has a glossy finish, while polyurethane has a satin or matte finish.
If you want to get rid of an old gloss coating and replace it with something else, then you would need to sand down your surface first before applying anything new. It’s important to know what products work best together so that you can avoid any confusion when painting or staining your piece in the future!
Here’s what you’ll learn;
- Tools for applying poly over polycrylic.
- Tips for working with poly on desks, picture frames, tables, e.t.c.
- How to apply oil-based polyurethane over polycrylic.
Let’s dive in.
Tools And Materials For Applying Poly Over Polycrylic
If you’re looking forward to getting a smooth and blemish finish of polyurethane over polycrylic, then you’ll need to acquire the following tools and materials.
- Vacuum cleaner
- Oil-based or water-based polyurethane.
- 120-, 180-, 220-, grit sandpaper.
- 80-grit sandpaper (for refinishing jobs).
- Tack cloth. Automotive polishing compound.
- Automotive rubbing compound.
- Dry lint-free
- Sanding block.
- Mineral spirits for oil-based poly, which dries with a slight yellowish tint.
- Distilled water for water-based poly.
- Natural bristle brush for oil-based poly and a nylon bristle brush for water-based poly.
Which Is Better—Oil-Based or Water-Based Polyurethane?
This is a question many homeowners have been asking recently. While there’s no simple answer to this question, a few things can help you make this decision.
The most important factor is likely to be the type of wood you are working with, as each requires different sealant types.
Water-based polyurethane is the most common in use today, and it’s easy to see why. Water is an effective solvent, which means it will penetrate the wood layers.
It’s cheap, but as a result, it isn’t an excellent choice for workpieces that will receive constant pressure. In addition, such woodworks will need to be repainted after a significant amount of wear and tear.
However, it’s possible to achieve an excellent sealing job with a water-based poly finish though you’ll need more than three coats.
If you ask me which is better, I’d say oil-based poly. This is so because oil-based poly is denser and can withstand excess pressure.
The difference comes in during curing. The curing temperature is higher than that of water, which allows the polymer to cure completely.
The curing temperature of the water-based product is lower. Thus, the finished product tends to soften at room temperature after curing. Oil, on the other hand, tends to harden when it’s fully cured.
Read more to find out what’s better between water-based poly and oil-based poly.
Tips for Working with Polyurethane
You need to be aware of the fundamental practices when working with polyurethane to achieve great wood finishes.
One of them is using gloves when applying, working at different angles, and allowing air to flow under the hands.
Working outside, in a well-ventilated workshop, or at a cold location is critical. Some coatings shrink while being exposed to extreme heat, e.g., water-based polyurethane, and should be stored carefully to avoid this shrinkage.
One of the best tips for working with polyurethane is to use smooth bristle brushes. When using soft-bristled brushes, the brush’s fibers can become rough and scratchy on the coating and remove some of the color or flexibility of the coat.
In addition, it’s important to always start on a clean surface to remove any built-up mess. Finally, never shake the polyurethane can to avoid air bubbles from forming.
How To Apply Polyurethane Over Polycrylic
When looking at different types of sealants for a project, one of the things you will want to think about is how you apply polyurethane to wood material.
Just like applying polyurethane over paint, and there’re some simple steps you can take to ensure you are ready to apply the material and have it sealed correctly in the end.
Before you start, wear respiratory protection.
Let’s get started.
Step 1: Sand the Surface
Sanding is an essential part of wood restoration. It’s not only used to help you get a better finish when it comes to sanding down rough or uneven wood, but it also helps to prevent warping.
Use the 80 or 100-grits sandpaper to lightly sand the wood and give it a nice smooth finish that is easy to work with. It will help you get rid of any flaws and give you a smooth and even finish.
Step 2: Remove the Dust
After the light sanding, it’s vital to remove the dust from a wood surface. Again, using a vacuum cleaner is as easy as pie.
Use the suction to clean the dust off the surface or warm water. When finished, you can empty the vacuum cleaner bag, rinse the piece of wood with a clean wet tack cloth, dry it, and it will be ready for use.
Step 3: Seal the Surface
Sealing furniture with polyurethane is an inexpensive and quick method for protecting it from the elements, from water damage to termites.
By applying a thick layer of the substance, you can create a barrier that keeps water and moisture out while at the same time keeping insects out as well.
There’re many different varieties of sealers available, so make sure to research and find one that best fits your furniture and budget. You can use any variety of polyurethane-based products, including sprays, liquid or gels, and blocks.
If you have never applied a sealer before, it can be intimidating to work with and even harder to understand how exactly it works.
Apply poly in thin layers over your furniture, using a specialized spray or gel, then once dry, wipe with a damp cloth or sponge. Check out how to apply wipe on poly.
While it’s a reasonably simplistic process, you must understand how and why your particular sealer works because if you don’t, then applying another sealer could cause more harm than good.
Step 4: Apply the First Coat of Polyurethane
After sealing with poly, it’s time to apply the first coat. Use a natural bristle brush for oil-based poly and a nylon bristle brush for water-based poly to apply a thin coat of poly.
Ensure to spread the poly in long and even strokes while keeping a wet edge. Make sure the strokes overlap for a uniform coat.
While applying the poly, be careful not to come up with drips or bumps on the workpiece. If you get some, shave them off using a razor blade, chisel, or sandpaper.
Step 5: Wet Sand the First Coat
After the first coat dries, wet sand the workpiece.
Wet sanding of polyurethane is a common practice. The process generally takes place on a horizontal or vertical grain.
It results in a finer texture, and as the first coat dries, a finer texture can be obtained. However, you can skip this step if you’re working with light woods.
For polyurethane coatings, most finishing techniques require a smooth, even application that occurs between coating coats. That’s why wet sanding is used. Wet sanding provides more even coverage and smoother application than can be achieved by using the roller or drum sander.
Step 6: Apply the Second Coat Before Normal Use
If you are concerned about getting a smooth, glossy finish with the first coat of the wood stain, you may want to opt for a second or third coat to achieve that finish.
You are applying your second coat for a uniform finish since the workpiece has been sanded in step 5 above.
This step should be done after 24 to 48 hours and you must use long brush strokes.
Step 7: Repeat Steps 5 and 6 if Needed
If you started with bare wood or didn’t have the best finish you hoped for by now, repeat steps 5 and 6 for a third coat. Then, if need be, apply to the fifth coat. Again, remember to lightly sand the surface or use a steel wool 00 pad.
Step 8: Polish the Surface if You Wet-Sanded the Second Coat
Polishing wood with an automotive rubbing compound is a simple process and one that many do-it-yourselfers can do.
The reason for this is to create a perfect shine on all surfaces before light handling.
To achieve the highest quality result possible, use an automotive rubbing compound designed to deal with a high degree of wood finish. Here, use a foam brush and avoid using too much pressure when wiping off the polish on the final coat (ensure not to sand this last coat).
Regardless of which type of cleaning compound is used, it’s important to follow the manufacturer’s direction to maximize perfection.
What’s the Difference? Polycrylic vs. Polyurethane
So what is the difference between oil-based polyurethane and polycrylic?
If your workpiece is used in high temperatures and high humidity places, then polyurethane will be more effective than polycrylic.
However, if you want to use a sealer, polycrylic paint will be the best high gloss finish as oil-based poly can form a yellow tint. Polycrylic is also available in satin finishes.
However, I wouldn’t advise you to use polycrylic on wooden floors or red mahogany stain instead, use Minwax polyurethane. This is because polyurethane is resistant to the elements, durable, and smooth. It’s also well known for its resistance to the effects of weather. In addition,it’s resistant to heat, moisture, chemicals, and acids and has a long shelf life when properly stored.
I prefer polycrylic and other water-based stains for wood projects that need quick finishing because it dries faster. Also, I will use it if I am forced to work inside a poorly ventilated room and in areas where temperatures are super low.
The other difference is, poly or oil-based stains aren’t as runny and drippy as the satin finish (polycrylic). I would therefore use poly on vertical surfaces, e.g., walls. You can also use it on wooden floors with high foot traffic.
If budget is a concern, use polycrylic because it’s cheaper than polyurethane.
Best Wood Working Practices
Before deciding on the type of sealer, you will use on your project; you must consider the following factors for your specific project.
- Temperatures or moisture: Will the workpiece gets exposed to high temperature or moisture? If so, oil-based polyurethane should be your pick.
- Are you using a light wood or applying the sealer on a white or light color painted project? If so, use polycrylic as oil-based polyurethane can form a yellow tint after the drying process forms a strong protective shell.
- Is the project a hardwood floor? If so, use oil-based polyurethane because it’s the most durable finish for flooring, whether it’s raw wood or not.
- Do you need a sealer that dries quickly? Better use polycrylic as it dries faster.
- Are you working without good ventilation? Use polycrylic because it’s less toxic than polyurethane. However, it’s always good to have adequate ventilation.
- Are you sealing a large wooden piece? Use polyurethane because polycrylic dries quickly. It will be challenging to achieve a smooth finish over a large area if you use polycrylic.
- Are you sealing a vertical surface? Polyurethane is easier to be applied on vertical woodworks as it is thicker and less prone to dripping.
- Are you working without gloves? Use polycrylic as you need soap and water to wash your hands.
- Are you on a budget? Polycrylic is less expensive than polyurethane. It also does well on wood painted white.
- Never sand deep into the stained wood.
Note: Polycrylic has a runny consistency which makes it challenging to apply.
How Do I Get A Smooth Finish With Polyurethane?
1. Is it More Difficult To Apply Polycrylic Evenly Than Polyurethane?
Yes, polycrylic is more difficult to apply evenly than polyurethane because it’s drippy and runner. You’ll need to apply thin coats, keeping an eye on drips before applying the subsequent coats.
2. Is Polycrylic Far Less Dangerous And Toxic?
Yes, polycrylic is less dangerous than polyurethane. Polyurethane is flammable and requires careful storage to prevent a fire. To add, it has a high VOC count; hence it can irritate your lungs. It’s not good on white paint as it won’t be crystal clear even though it dries completely clear – it creates an amber hue on light colors.
3. Can You Use Oil-based Polyurethane Over Polycrylic?
Yes, you can use oil-based polyurethane over polycrylic on a wood surface as it’s more resistant to damage, is a waterproof seal, and durable than other sealers. However, water-based polyurethane is also perfect.
4. Which Is Better, Polyurethane Or Polycrylic?
Both these finishes are excellent and perfect for your projects, but polyurethane is better than polycrylic. This is because polyurethane has better adhesion and durability and is meant for indoor and outdoor DIY projects. Polycrylic, on the other hand, isn’t as durable as polyurethane. It’s meant for interior surfaces only – it can give you a milky finish when put on dark-colored paints.
5. Is Polycrylic Different Than Oil Based Versions Of Polyurethane?
Polycrylic finish is based on water alone, while polyurethane is based on oil and water and has the same properties as melted plastic. Both are great finishes; only that polyurethane is more durable than polycrylic.
As mentioned, it’s ok and recommendable to put polyurethane over polycrylic. However, when you are ready to begin applying the polyurethane on wood, you should apply thin layers.
Applying too much polyurethane can result in a cake-like appearance and can cause excessive swelling of the area where you sprayed the polyurethane.
The first coat of polyurethane finish should be dry completely in about forty-five minutes. The polyurethane should have dried when you are ready to cover the entire surface with more coats of polyurethane. Each coat of polyurethane you apply will produce a thicker, glossy finish. Each coat will also create a different texture and colors.
Happy finishing with this protective finish.