If you are new to using polyurethane, this article is a must read. I know when I started wood working, I really could have used this kind of information, however, the internet was non-existent at the time. What you create with wood is important though I do feel that how you finish it can either improve and highlight your work or ruin how it looks. This is not good, especially if you plan on selling your wood working.
So, what is the difference between oil and water-based polyurethanes? Polyurethane comes in either an oil or water base. Both types of polyurethane have specific uses. Oil-based polyurethane would be used on flooring and furniture. Water- based polyurethane is used on flooring, woodworking projects, shelving and some furniture pieces. There are other applications for both types of polyurethane, just not included here.
Choosing the wrong type of polyurethane can lead to a different look after your project ages. It is a good idea to educate yourself on the polyurethane types, so you are happy with the final product. Just because I mentioned previously you might not use water-based poly on flooring, it doesn’t mean that you can’t. So, let’s look at the traits of both polyurethane’s and what you would consider using either for.
For the remainder of this article we will sometimes reference polyurethane as poly. Let’s get started!
5 Traits of Water and Oil Based Polyurethane’s
At a high level, here are the main traits for each type of poly.
Oil-Based Polyurethane Traits
- Drying time is Slower
- Stronger Smell
- Less Sensitive to Surface Abrasion
- Darkened finish
- Lower Cost
Water-Based Polyurethane Traits
- Drying time is Faster
- Lighter Smell
- More Sensitive to Surface Abrasion
- Clear finish
- Higher Cost
Below, I will touch on these traits in depth. I will also explain why your floor style should determine what type of polyurethane you should buy.
Oil-Based Polyurethane Traits
Oil-based polyurethane leads to a highly durable finish. You will be happy to know it is especially easy to apply.
Oil based poly is heat resistant, chemical resistant, and virtually scratch resistant. Of course, this applies only and when it is administered according to instructions. Oil-based polyurethane results in a lustrous finish that deepens a wood floors coloring.
Oil Based Drying Time is Slower
Oil-based polyurethane can be administered in one or two coats per day. This is dependent on the instructions on the can.
Make sure to wait at least twenty-four hours following the last coat before walking on it. Wait forty-eight hours before transferring your furniture back into the room. If you can wait longer, you run into less chances of having an issue.
Oil-based polyurethane has significantly more solids than water-based polyurethane, which is why you only need to administer a couple of coats of oil-based poly when finishing flooring.
Be aware that oil-based poly can take as long as 30 days to fully cure, however, it is fully useable much sooner.
Oil Based is Stronger Smelling
Oil-based polyurethane has a fumy, strong smell. Wear a respirator and keep pets and anyone with breathing issues away from the odor of oil-based polyurethane.
Keep the area where oil-based polyurethane is administered ventilated. The odor will remain until the polyurethane is fully cured in one to three days.
Oil Based is Less Sensitive to Surface Abrasion
Oil-based polyurethane finishes are softer and less sensitive to surface abrasion. However, it dents more easily.
Basically, what this means is because of the compounds in an oil-based poly, the product will depress, if enough pressure is applied, but it won’t scratch easily for the same reasons. Does that make sense to you? Hopefully!
Preventing debris from coming into contact with the floor, is important when you have an oil-based polyurethane finish. For example, using pads under furniture will help to prevent the floor from denting.
Oil Based Poly Has a Darker Finish
There isn’t a lot to cover here, except that oil-based polyurethane finishes have an amber hue which rapidly darkens the wood. As time goes on, the amber tone deepens significantly.
Lower Purchase Price
Oil-based polyurethane costs around two to three times less than water-based polyurethane. When coats and costs per application are calculated, there is a range of 45 to 60 cents per square foot for oil-based polyurethane.
Water-Based Polyurethane Traits
Water-based polyurethane is widespread because of its low toxicity and its light smell. It dries much faster too. Wood working hobbyists will most likely use this type of poly for projects versus the oil-based variety.
Water Based Poly’s Drying Time is Faster Than Oil Based
Water-based polyurethane can be recoated in four to six hours. Four coats can be administered in a day.
Check the instructions on the can before administering the coats for specific application requirements. Furniture should not be placed on the floor for at least twelve hours after the final coat is applied.
Water based poly dries much faster than oil based, however, it still takes approximately 2 weeks for water based to full cure. This is something you will want to consider if applying to a wood floor.
Water Based Poly Has a Lighter Smell Than Oil Based
Water-based polyurethane finishes have a lighter smell. No respirator is necessary. Still not a bad idea, though. If you choose not to use a respirator, then try opening windows to get some air flow moving through the workspace. It will help keep the smell under control and will speed up the drying time.
Water Based Poly is More Sensitive to Surface Abrasion
Water-based polyurethane has a much harder finish which makes it much more sensitive to surface abrasion. As mentioned with the oil-based poly’s, using pads under furniture is a good idea for water-based poly as well. Vacuuming your flooring routinely with a hardwood floor vacuum is recommended, which will lessen the chances of scratching.
Water Based Poly Has a Clearer Finish
Unlike oil-based, water-based polyurethane dries clear and will stay clear over time.
There really isn’t much more to say here.
Water Based Poly Comes with a Higher Purchase Price
The cost for water-based polyurethane is two to three times higher than oil-based polyurethane. When coats and costs are calculated, there is a range of 90 cents to $1.45 per square foot for water-based polyurethane.
The Type of Wood Floor Will Determine What Kind of Polyurethane You Buy
The type and look of your floor are what matters most – aka. the finished product!
The smell, drying times, and prices are less important factors in the polyurethane purchase decision-making process.
The smell of water and oil-based polyurethane is temporary. However, you will have to live with the look of your floor after water or oil-based polyurethane is administered for many years.
You must ask yourself this question: Will your floor look better with an amber coat or a clear coat?
Water-based polyurethane will result in a floor that retains its color, since it produces a clear coat. Wood that is white, grey, or light looks better with a clear coat.
Woods that have a yellowish hint in them, such as fir, pine, and ash, will become yellower with an oil-based polyurethane finish. Go with water-based polyurethane, if that is a look that you want to avoid.
Oil-based polyurethane enriches darker wood tones by adding an oily sheen and an amber hue. Oil-based polyurethane can lead to much more vibrant color in cherry, red oak, or exotic woods such as teak.
Don’t forget to also consider the durability required for your finished product, whether you put poly on flooring furniture or other wood projects.
If the area gets a lot of use, you might opt for oil-based vs water based. Otherwise, using water-based versus oil based for low traffic areas is the better option.
Now, you have the information you need to make the best choice. Just remember the two most important factors here are the finished color and the durability of oil-based poly versus water-based poly.