What To Consider When choosing Polyurethane
Whether you’re building a chair, a cabinet or simply looking for a top coat for your hardwood floors, polyurethane is one of the best finishes you can use on your projects. No matter what kind of wood you use, its quality or strength, without a good finish it will wither and dry before long.
Polyurethane is a specific kind of finish that will provide the highest protection money can buy. There are two main types that you can choose from: oil based and water based.
Oil Based Polyurethane
Available in both spray and brush on version, oil based polyurethane will give wood an amber finish, covering its natural color. The advantage, however, is that it’s more wear proof and well suited to outdoor projects or items that will incur a lot of wear and tear.
Although it’s long lasting, this finish dries slowly. It will be dry to the touch in about two hours and ready for a second coat only six to twenty four hours later.
Another potential issue with it is its odor. It’s quite pungent and will not go away until it’s completely dry. There is no way to minimize it and the best advice is to leave your work to dry overnight somewhere out of smell range.
You’ll also want to make sure that you’re in a well ventilated area when applying this compound as it emits toxic VOCs. Luckily, it’s pretty easy to work with as it’s self smoothing and it’s likely you won’t need more than one coat for adequate protection.
Water Based Polyurethane
Water based polyurethane will not change the natural coloring of the wood but it is likely to withstand less abuse than its oil based counterpart. This product dries quicker than the oil version and you will be able to apply multiple coats in far less time.
Another advantage is that this water based finish has no odor and has lower toxicity making it less of a pain to work with. It’s also easier to clean up with a bit of water and soap.
This is ideal for projects that don’t require heavy duty coating but it can still provide solid protection if applied in multiple coats. However, keep in mind that that means you will need more product to cover the same surface area and therefore the price of the finish will go up.
Water-Based Oil-Modified Polyurethane
If you want to have the best of both worlds, the water-based oil-modified might be the polyurethane for you. Just like the pure water-based, it’s non-toxic and dries quickly and just like the oil based, it dries up to a nice amber color. It’s also more durable than just the water based one without any of the offending odor issues.
What kind of finish should you choose?
Another important aspect to consider is what sort of finish you will need for your project.
Matte Finish
This finish has no luster which can be off putting to many customers. It’s ideal for those who love to see the natural wood color shine through with as little distortion as possible.Satin
Finish
This is one of the most popular choices because it’s shiny but not too shiny and it allows the natural texture and beauty of the grain to shine through.
High Gloss
This type of finish is not a very popular choice. That’s because it has the most amount of luster and will show every scratch, trace or spot. It’s reserved for specialty use that sees very little traffic.
Semi Gloss
Almost as popular as the satin finish, the semi gloss has a bit more luster and it’s also less forgiving. It will require more maintenance but it will also allow the beauty of the wood to shine through.
What is the best way to apply polyurethane?
There are three application methods to choose from, when working with polyurethane: brush on, wipe on or spray on.
Brushing on is the best option for flat surfaces that don’t require much nook and cranny work. It will work like a charm without any bells and whistles.
Wipe-on is the best option for you if your project has a lot of crevices or rounded surfaces as it will allow you to easily cover the area uniformly.
Spray on is a good solution for harder to reach areas but it has a few drawbacks. It’s harder to work with and more difficult to achieve uniform application. It will also require care and preparation to avoid dripping.
How do you apply polyurethane?
The most popular application method is brush on and it’s quite straight forward. Apply the product gently in the direction of the grain. If you’re working with a clear, water-based finish you can sand lightly after it dries and apply a second or even a third coat, until you feel you have the appropriate coverage.
When working with clear polyurethane, make sure to stir it before use and while coating your project. You don’t want residue depositing on the bottom of the can. However, you won’t want to shake it either because that can cause bubbles which will show up on the wood.
Work in small sections and apply light layers. This eliminates the potential for contaminants to stick to the coat and show up in the dried finish.
FAQ
What are the different types of polyurethane finishes?
Polyurethane finishes come in four varieties: matte, satin, soft gloss and high gloss.
Is polyurethane toxic to humans?2
Yes, polyurethane can be harmful to humans because of the fact that it emits Volatile Organic Compounds or VOCs which irritate the lungs and airways and can cause inflammation and asthma attacks. When working with polyurethane, make sure you’re in a ventilated room and you’re wearing proper protection.
How many coats of polyurethane should I use?
This depends on the type of polyurethane you are using. Typically, an oil based product will only require a couple of coats but you will need to wait about 24 hours between applications. A water based solution will need more coats but it dries much faster.
What is the best way to apply polyurethane?
The best way to apply polyurethane is with a brush. Make sure to choose a high quality synthetic brush to facilitate a smooth application. Additionally, always apply in the direction of the wood’s grain.