When it comes to choosing a protective clear finish for wood projects, polycrylic and polyurethane are two of the most popular options. But what exactly is the difference between polycrylic and polyurethane? This comprehensive comparison guide examines the key differences between these two clear finishes to help you determine which is better for your specific project needs.
Overview of Polycrylic and Polyurethane
Polycrylic is a water-based protective clear coating that provides a crystal clear, non-yellowing finish. It dries fast, is low odor, and can be cleaned up with water. Polycrylic has a acrylic polymer base and is made by combining acrylic monomers with other acrylic polymers.
Polyurethane is an oil-based protective clear finish that provides a warm golden glow and enhances the natural color and grain of wood. Oil-based polyurethane has a urethane polymer base and is made by combining organic units containing urethane links. Polyurethane is known for its durability and protective qualities.
Both polycrylic and polyurethane form a plastic-like coating to protect the wood underneath. But there are some notable differences between these two finishes that make each better suited for certain applications.
Key Differences Between Polycrylic and Polyurethane
Ingredients
- Polycrylic is water-based, meaning its main ingredient is water. It also contains acrylic polymer emulsions.
- Polyurethane is oil-based, meaning its main ingredient is petroleum-derived mineral spirits. It also contains urethane polymers.
Dry Time
- Polycrylic dries much faster than polyurethane. It’s usually dry to the touch in about 1 hour and can be recoated in 2-3 hours.
- Polyurethane has a significantly longer dry time. Oil-based polyurethane takes 5-6 hours to dry to the touch and 24 hours between coats.
Odor
- Polycrylic has a mild odor during application that fades quickly as it dries.
- Polyurethane has a strong solvent odor that can linger for several days until fully cured. It needs proper ventilation during application and drying.
Cleanup
- Polycrylic cleans up easily with soap and water. No mineral spirits necessary.
- Polyurethane requires mineral spirits for cleanup of brushes and equipment.
Sheen Levels
- Polycrylic is available in semi-gloss and satin sheens. It does not come in high-gloss.
- Polyurethane can be formulated in gloss, semi-gloss or satin finishes. Oil-based poly also comes in a matte sheen.
ambering/yellowing
- Polycrylic resists yellowing and remains crystal clear as it ages. It’s a good choice for light colored woods.
- Polyurethane will develop an amber tint over time that enhances natural wood tones but can look yellow on light woods.
Durability
- Polycrylic forms a durable yet flexible coating that resists fingerprints, water, household chemicals and food stains. It can scratch or mar if abused.
- Polyurethane provides a harder, more scratch and stain-resistant coating. It also better prevents moisture penetration. But it can become brittle with age.
VOC Content
- Polycrylic has zero VOCs (volatile organic compounds). It meets the most stringent environmental regulations.
- Polyurethane contains VOCs from solvents like petroleum distillates. Levels vary by product line.
Wood Enhancement
- Polycrylic offers only minimal wood enhancement, maintaining a clear, natural look.
- Polyurethane enriches wood tones and grains with its warm amber glow. Enhancement deepens over time.
Cost Difference
- Polycrylic is the more affordable option for protective clear coatings.
- Polyurethane costs notably more than comparable water-based finishes.
Sanding Between Coats
- Polycrylic can be recoated without sanding between coats as long as done within the manufacturer’s recommended recoat time.
- Polyurethane needs thorough sanding between coats to ensure proper adhesion and a smooth final finish.
Key Questions When Choosing Between Polycrylic and Polyurethane
When deciding whether to use polycrylic or polyurethane for a wood project, it’s helpful to consider these key questions:
What Type of Wood Are You Finishing?
- Polycrylic is best for light woods where yellowing needs to be avoided, like maple, birch, ash, and pine.
- Polyurethane works well for darker woods where its amber tone enhances natural color, like cherry, walnut, mahogany.
Does Fast Drying Matter?
- Choose polycrylic if you need the finish to dry quickly, either due to time constraints or for quick recoating.
- Polyurethane requires patience as it takes significantly longer to dry and fully cure.
Is Odor a Concern?
- Polycrylic has very low odor, making it ideal for indoor use.
- Polyurethane has strong solvent fumes and requires good ventilation during drying.
What Sheen Level is Desired?
- For a satin or semi-gloss look, either finish can be used.
- If high-gloss is preferred, polyurethane is the better choice.
- For a matte look, oil-based polyurethane is required.
How Durable Does the Finish Need to Be?
- If maximum scratch and moisture resistance is needed, polyurethane is the tougher option.
- Polycrylic offers sufficient durability for many applications while still being easy to apply and repair if needed.
Is an Ambered Finish Desired?
- Polycrylic maintains a crystal clear look over time.
- Polyurethane will take on an attractive amber patina as it ages.
Are there Health/Environmental Concerns?
- Polycrylic’s low VOCs and water cleanup make it the better choice for indoor air quality.
- Polyurethane requires proper ventilation during application and emits moderate VOCs.
Best Uses for Polycrylic
Here are ideal uses for water-based polycrylic:
Children’s Furniture and Toys
Polycrylic is the safer choice for coatings that children will contact since it emits no VOCs or fumes. Easy soap and water cleanup is also a benefit for children’s items.
Light Colored Wood
On woods like maple, birch, pine or ash, polycrylic resists yellowing and provides long-lasting clarity. Polyurethane’s amber tone would discolor light woods.
Indoor Projects
For any interior wood projects where low odor is an advantage during application and drying, polycrylic is the best option.
Small DIY Projects
For smaller home projects, the fast dry time of polycrylic allows for quick recoats so the project can be completed quickly. Less dry time also means less dust settling between coats.
Repairable Finishes
Since polycrylic can be easily repaired by light sanding and reapplying a fresh coat, it’s ideal for surfaces that may need touch-ups down the road.
Kitchen and Bathroom Projects
Polycrylic offers the moisture, chemical, and stain resistance needed for high use areas like counters, tables, and bathroom vanities while maintaining a clear finish.
Best Uses for Polyurethane
Here are ideal applications for oil-based polyurethane:
Hardwood Flooring
Polyurethane’s tough, protective finish makes it an excellent choice for hardwood flooring that endures heavy foot traffic. Most flooring pros prefer oil-based poly.
Furniture
For authentic wood furniture, polyurethane provides maximum stain, scratch and moisture resistance to protect the surface while enhancing wood grain.
Exterior Projects
When outdoor durability under sun, rain and snow is needed, polyurethane is typically the best choice for optimal protection.
Dark Stained Woods
Polyurethane enriches the look of darker wood tones like walnut, cherry, mahogany or espresso stained wood, improving color depth as it ages.
High Use Surfaces
For tables, desks, bars or other surfaces subject to heavy use and abuse, polyurethane offers the most durable and rugged finish.
High Gloss Surfaces
Oil-based poly can be formulated in high-gloss sheens for applications like molded table edges and accents. Polycrylic lacks a true gloss option.
Application Tips
Proper application technique is important for achieving the best results from either polycrylic or polyurethane. Here are some application tips:
Prep the wood by sanding smoothly up to 220 grit and thoroughly removing dust. For polyurethane, tack cloth is recommended after sanding for a dust-free surface.
Choose a good quality brush made for water-based (polycrylic) or oil-based (polyurethane) coatings. Use a high-quality mini foam roller for large surfaces.
Read all label instructions and carefully follow the manufacture’s recommended application procedures.
Apply thin coats in even, overlapping strokes while maintaining a wet edge. Thin coats provide better self-leveling and a smoother final result.
Allow proper drying time between coats. Recoat polycrylic when dry to the touch in 2-3 hours. Recoat polyurethane after 24 hours.
Sand lightly with 220 grit sandpaper between all coats for maximum adhesion and a glass-smooth final build. Polycrylic may not need sanding if recoated within the recoat window.
Add coats until desired coverage is achieved, typically 2-3 thin coats for an adequate film build. Too many coats can lead to clouding or cracking.
Consider adding an extra final coat on surfaces that will endure heavy wear like tabletops or flooring. The extra protection is worth the time investment.
Allow the finish to cure fully before use. Polycrylic cures in 24 hours. Polyurethane requires 7-30 days to fully harden, depending on humidity and ventilation.
Maintenance and Repair
Both polycrylic and polyurethane will last for many years with proper care and maintenance. Here are some tips for keeping these finishes looking their best:
- Use coasters under glasses and placemats under dishes to prevent moisture damage and staining.
- Wipe up spills promptly to avoid potential finish damage. Avoid abrasive scrubbing.
- Use furniture leg protector pads under heavy furniture to prevent scratches.
- Keep wood out of direct sunlight to reduce fading or yellowing over time.
- Dust frequently with a clean soft cloth.
- Clean using a mild soap and water solution. Avoid harsh cleaners.
- Don’t place hot items directly on the surface. Use trivets and hot pads.
- Consider reapplying 1-2 fresh coats every 2-5 years for added protection.
For spot repairs:
- Sand damaged areas completely down to bare wood.
- Wipe away all sanding dust.
- Reapply polycrylic or polyurethane as directed, feathering out from repaired area.
- Apply at least 2 overall coats for an even appearance.
Frequently Asked Questions
Does polycrylic yellow over time?
No, polycrylic maintains its crystal clear finish as it ages. It will not cause yellowing on light colored woods.
Can polycrylic be used over polyurethane?
Yes, polycrylic can be safely applied over cured oil-based polyurethane if desired to renew a finish or change sheens. Proper prep and application keys are followed.
Is polycrylic as durable as polyurethane?
Polycrylic provides sufficient protection for many applications but polyurethane is generally regarded as the most durable option, especially for flooring.
Can polycrylic be used on floors?
Polycrylic can be used on wood floors but it is not as hard-wearing as polyurethane. It may require more frequent recoating. Proper application is crucial.
Does polycrylic leave brush strokes?
Like all finishes, polycrylic can leave brush marks if applied incorrectly or too thick. Applying thin coats with a high-quality brush minimizes brush stroke visibility.
How do you get a smooth finish with polycrylic?
Sand thoroughly between coats, apply thin even coats, use high-quality applicators, maintain a wet edge, allow proper drying time, and sand again at the end for a glass-smooth polycrylic finish.
Is polycrylic food safe once cured?
Yes, fully cured polycrylic creates an inert non-toxic coating that is FDA approved for indirect food contact. Avoid direct food contact when still wet.
Can polyurethane be applied over polycrylic?
Oil-based polyurethane should not be applied directly over cured polycrylic. The products are incompatible and may not properly bond. Proper prep is required first.
Conclusion
When choosing between polycrylic vs polyurethane, consider the project needs in terms of wood type, desired sheen, use environment, durability needs, and application factors. Polycrylic offers fast-drying convenience while polyurethane provides ultimate durability. For many projects, either finish can provide an attractive protective coating for woodwork. Just be sure to follow all preparation and application instructions carefully for best results. With the right product choice and careful technique, you can get a beautiful, long-lasting clear finish.