Water-Based vs Oil-based Polyurethane: Which do you Need?

The difference between water-based and oil-based polyurethane lies in their color, drying time, durability, cost, toxicity, and odor. While both offer good protection, oil-based polyurethane is generally more durable, but water-based polyurethane is less toxic and dries faster. The choice depends on personal preference and project requirements.

We tested both water-based poly and oil-based poly on different parameters like color quality, drying time, and odor to come up with this comprehensive article.

Water-Based vs Oil-based Polyurethane: Practical Differences

Supplies ready for testing water-based and oil-based polyurethane
Supplies ready for testing water-based and oil-based polyurethane
FactorsWater-Based PolyurethaneOil-Based Polyurethane
Color QualityClear and colorlessAmber and yellowish
Dry TimesDries quicklyDries slowly
DurabilityLess durableMore durable
PriceSlightly more expensiveSlightly less expensive
ToxicityLess toxicMore toxic
OdorMilder odorStronger odor
ApplicationInterior use onlyInterior and exterior use
A quick comparison of water-based and oil-based polyurethane

Color Quality

Color is a significant factor to consider when selecting between water-based and oil-based polyurethane finishes.

Oil-based finishes provide a warm, golden hue that can enrich wood surfaces, particularly darker woods such as mahogany and walnut.

Golden hue of oil-based polyurethane
Golden hue of oil-based polyurethane

However, oil-based poly tends to yellow and darken over time.

On the other hand, water-based poly dries clear and stays clear, which doesn’t impact the natural color of the wood or yellow over time.

Ultimately, the choice between the two types of finishes comes down to personal preference and the desired aesthetic outcome.

Dry times

Polyurethane finishes have varying drying times, affecting the pace of woodworking projects.

Water-based polyurethane dries quicker than oil-based, taking 2-3 hours instead of 24 hours or more.

Oil-based polyurethane still wet even though water-based polyurethane dried
Oil-based polyurethane is still wet even though water-based polyurethane dried

Water-based polyurethane is ideal for tight deadlines, while oil-based gives ample time for even application, a boon for larger projects.

It’s also crucial to consider the surrounding humidity and temperature as they affect the drying time.

Durability

The protection that water-based and oil-based polyurethane finishes offer to wood is excellent, but oil-based polyurethane is generally regarded as more durable than water-based polyurethane.

Due to its thicker nature and greater scratch resistance, oil-based polyurethane can better withstand physical impact and scratches, making it an excellent option for high-traffic areas like hardwood floors.

Yet this may not be always true, and it can vary based on the product quality.

Nonetheless, both finishes provide sufficient protection against liquid spills, scratches, and general wear and tear.

Price

The price of polyurethane can vary depending on the brand and type chosen, but generally, water-based products cost slightly more than oil-based products.

However, the price difference of $3 – $5 is insignificant.

It’s also worth noting that oil-based polyurethane has a longer drying time, leading to longer project completion time and additional labor costs.

Toxicity

Oil-based polyurethane generally has higher levels of toxicity than water-based finishes as it contains more volatile organic compounds (VOCs).

A gallon of oil-based polyurethane typically contains around 500 VOCs, which can pose a health risk if inhaled over a prolonged period.

In contrast, water-based polyurethane contains only 100 to 200 VOCs per gallon, making them a safer option.

Although water-based polyurethane is less toxic than its oil-based counterpart, taking the necessary precautions when handling any finish is crucial.

This includes ensuring proper ventilation in your workspace, using protective gear such as gloves and a mask, and adhering to the manufacturer’s safety guidelines.

Odor

Oil-based polyurethane releases a strong and persistent odor, which can be overwhelming and linger for several days.

This can make working in an enclosed space or for those sensitive to strong smells challenging.

It can sometimes cause respiratory problems, headaches, and dizziness if inhaled over a prolonged period.

In contrast, water-based polyurethane has a milder and less persistent odor that dissipates quickly, making it a more suitable and safer option.

Applications: When to Use Them

Applying oil-based polyurethane
Applying oil-based polyurethane

Water-based polyurethane is an excellent choice for indoor applications, especially when air quality is a concern.

Its quick drying time, low VOC levels, and mild odor make it easy to use in enclosed spaces.

This type of polyurethane is suitable for use on furniture, cabinets, and floors where durability is required.

In contrast, oil-based polyurethane is better suited for outdoor applications like decks and fences.

It provides a deeper and richer color that enhances the natural beauty of wood and can withstand harsh weather conditions.

However, it emits a stronger odor and has a higher VOC content, making it unsuitable for indoor use without proper ventilation.

Applying water-based polyurethane
Applying water-based polyurethane

Pros and Cons of Water-based Polyurethane

ProsCons
Quick drying timeCan raise the grain of the wood
Low VOC contentMore expensive than oil-based polyurethane
Mild odorLess durable than oil-based polyurethane
Easy to clean up with waterIt may require more coats for desired finish
Clear finish that doesn’t yellow over timeCan be difficult to apply it evenly
Pros and cons of water-based polyurethane

Pros and Cons of Oil-based Polyurethane

ProsCons
Rich, warm colorStrong, lingering odor
More durable than water-based polyurethaneLonger drying time
Can effectively hide scratches and dentsHigh VOC content
Cheaper than water-based polyurethaneHarder to clean up with solvents
Can be applied evenlyCan yellow over time
Pros and cons of oil-based polyurethane

Final Thoughts

Considering all the factors we have discussed, it’s not easy to conclusively say which polyurethane type is superior.

Oil-based and water-based polyurethane have their unique advantages and disadvantages, and the best choice depends on your project’s specific requirements and personal preferences.

For example, if you are working on a project with a tight deadline, you may want to use water-based polyurethane due to its faster drying time.

Alternatively, if you want to add a rich, warm color to your project and have enough time, you may prefer oil-based polyurethane.

Another important consideration is the level of toxicity you’re comfortable with.

Water-based polyurethane might be the better option if you want to reduce your exposure to VOCs and are sensitive to strong odors.

However, if you’re working in a well-ventilated area and don’t mind a stronger odor, you might want to consider oil-based polyurethane.

Ultimately, you should carefully assess your project’s requirements and personal preferences before deciding which type of polyurethane to use.

And if you’re unsure, you can always test both types on a small area before making a final decision.

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Frequently Asked Questions

What is better, oil or water-based polyurethane?

Both oil and water-based polyurethane have their advantages and disadvantages. However, with technological advancements, water-based polyurethane formulations have become more durable and offer the same level of protection as oil-based polyurethane.

Is water-based polyurethane waterproof?

Water-based polyurethane can resist water and other liquids but is not entirely waterproof. It can still be damaged by prolonged exposure to water, which can cause swelling and warping of the wood.

Is water-based polyurethane harder than oil-based?

Water-based polyurethane is generally not harder than oil-based polyurethane. However, water-based polyurethane has been improved to provide similar levels of durability and hardness as oil-based polyurethane. The choice between the two depends on personal preference, project requirements, and environmental considerations.