Polyurethane is essentially a liquid plastic resin available in oil and waterborne formulations. While you get them in containers, they are also available in spray cans. Using cans is fully intuitive – just aim your wood surface and pull the trigger! But of course, get the right spray for a particular job. This write-up will guide you in detail about polyurethane aerosol spray, best products, applications, and other related matters.
Why Use Polyurethane Spray-Can?
Spraying canned polyurethane is an effortless but effective way to protect your wooden furniture and other interior wood items. The conveniences it brings are unmatched by any other method like brushing, wiping-on, or even using a gun. It’s a guarantee of a clear wood coat.
Assume you’re wiping-on with a cloth or pad or brushing with a paint-brush. Remember, you are at the full risk of leaving bubbles in your finish if you are not slow and precise enough at application. What it means is an uneven and non-smooth surface as opposed to a crystal-clear one. Stirring the poly, wiping the edge with a brush, or other correct brushing techniques can also be very tricky for you to ensure a moisture-free non-cloudy finish.
Use of spray cans will keep you far from any of those challenges, providing you with the opportunity to achieve a delicate surface finish with little or no mistakes. It’ll remind you – to err is human, but tools are technically precise, despite a few drawbacks they are associated such as unsuitability to larger projects. You will like to use aerosol cans for many other reasons, including affordability, quickness, ease-of-use, and versatility.
Best Polyurethane Spray Cans – Woodinto Selection
Almost all wood finish (mostly the familiar types) is available in canned-aerosol formulations, including the oil-based and water-based polyurethanes. Since we are explicitly exploring polyurethane in this article, choosing the best polyurethane sprays was the central part of our research. According to our study, the following are the best poly spray-cans that we have managed to enlist.
Best Overall: MINWAX Fast-Drying Polyurethane Aerosol
Best for Indoor: RUST-OLEUM Varathane Polyurethane Spray
Best for Outdoor: Rust-Oleum Varathane Spar Urethane
Best for Indoor & Outdoor: Minwax Helmsman Spar Urethane
Best Oil-Based: Deft Defthane Interior/Exterior Poly Spray
Best Water-Based: RUST-OLEUM Ultimate Polyurethane Spray
Polyurethane Spraying: Gun vs. Aerosol Can
Fairly speaking, using a sprayer or gun to spray polyurethane from regular containers always gets professional preference. The process requires two things – (i) polyurethane and (ii) a separate spray gun. In addition to that, few additional steps are necessary for spraying polyurethane with a gun. But aerosol spray cans (what we generally call polyurethane spray) need nothing additional. No mixing, no cleanup – they are just as said – take a can and spray on your aimed surface.
Applying urethane from containers with a sprayer can indeed cover a larger area indoors and outdoors while offering a long-lasting finish, but it costs more. Spraying aerosol poly cans are an economical and unparalleled option for crystal-clear finishing, especially on small surfaces. Spray-cans are quick, easy and versatile compared to highly-expensive spray rigs, but not for covering a wider area.
Polyurethane:- Spray vs Brush-On vs Wipe-On
Every poly comes with a suggested application method, typically brushing or wiping on. Spraying with a high-end sprayer is not uncommon too. But, use of aerosol cans is the most convenient way to apply polyurethane to date.
Regular oil-based polys are known as Wipe-on polyurethane. Opposite to that, brush-on polyurethane means water-based formulations. When they (both) are converted to aerosol forms to be sprayed from cans are known as Spray polyurethane.
As you know about oil and waterborne polys, you should be already clear about the differences between wipe-on and brush-on polys. Added information will help you understand more where aerosol sprays stay as an addition.
Wipe-ons require to be thinned with mineral spirits, while brush-ons or spray polys need no thinning. You don’t need to worry about drips and brush marks in wipe-on and aerosol polys, while it’s a common risk phenomenon in brush-ons. But wipe-on and spray offer coats three times thinner than brush-on polys. Brush-on and aerosol sprays dry faster than wipe-ons. Regarding application cost, aerosol spray wins over the rest two, while wipe-on polys are less expensive than brush-on polys.
Selecting the Right Polyurethane Aerosol Spray Cans
Aerosol cans of polyurethane allow you to be more maneuverable, enabling you to complete a complex project conveniently and quickly. Many other benefits are associated with standard aerosol spray cans. But how to select the right one for your project? Here are some essential facts and tips:
- Determine where you’re going to apply the spray. You should get the oil-based, anti-UV sprays for exterior projects, while waterborne spray will suit indoor wooden surfaces more.
- If you consider it for long-lasting outdoor projects, gloss oil-based units can do the job best. But for safe indoor use (low VOCs, less odor) with lower durability, waterborne aerosols should get your preference.
- Pick a spray based on the desired appearance of finish, such as waterborne for a clear finish or oil-produced for a rich amber finish.
- Check the capacity to fight against humidity and heat, particularly for dining tables or cabinets.
- Drying time is another essential consideration. Get the fast-dry sprays if you need the project done promptly.
- Pick a thicker spray if you need a thick surface layer and to avoid more coatings.
How to Spray Aerosol Poly – Step by Step Guide
Make sure your piece of wood is smooth and even through sanding as required, ready to get a protective coat. Then perform the following steps:
- Shake the Can
Polyurethane contents of any aerosol tend to settle at the bottom. Shake for a minute to ensure proper mixture of the polyurethane, solvent, sheen, and propellant before pressing the nozzle on your wooden surface.
- Position Perfectly
Place your project like you’re going to spray the wood surface horizontally. This position will prevent the wet finish from running down the vertical side; rather, it will pull that down into pores.
- Try Thin
Apply thin and wait to dry before a second coat. Thin coats don’t run or sag, and they develop cracks rarely. Unless you need a thicker spray, mainly, stick to thinner coats.
- Spray from Distance
For a correct spray pattern, keep the nozzle tip about 12 feet away from the surface where you’re aiming. Spraying from a too close distance leaves much poly, and applying from much distance leads the finish to start to dry in the air. Lastly, spray specks of polyurethane instead of pouring liquid all at once to get a perfect result.
- Move and Be Constant
Start spraying from a few inches away from the edge of the one side, and slowly move from one end to the other side until you reach a few inches from the corner of that edge. Repeat the process again and again, overlapping one slightly by the other. Cover the entire surface this way, as it will help you from any sag.
- Let it Dry and Repeat
Canned spray is used to create thin coats, which naturally dries faster. Wait until the coat is thoroughly dried before applying another coat. Sand with 220-grit paper between coats, if necessary. Repeat the 5th step.
- Clean Nozzle
Turn the aerosol can upside down. Depress the nozzle tip until it stops coming out anything else except for clear propellant. Clear the nozzle well and store the can as instructed by the manufacturer.
Spray Polyurethane Dry Time & Curing
How long does polyurethane spray take to dry and cure? It mainly depends on the type of poly. If it’s waterborne, a coat should dry in less than 2 hours and be ready for the next coat. Oil-based spray will generally take more time to dry after a coat – generally, around 6 hours, which may go up to 12 hours depending on humidity, temperature and thickness. Curing means entirely ready for use, which takes at least 24 hours for water polys and a week (may go up to 30 days) for oil polys.
What happens if you don’t sand between coats of polyurethane?
Sanding between spray coats helps to achieve more adhesion between the layers. That means failing to do may result in less adhesion or less smooth/even surface some time, though not in every case. Other than that, there is no significant impact of such mid-point sanding – even some spray polys do not require sanding at all.
How long do polyurethane sprays last?
Polyurethane sprays have different lifespans subject to their type, formulation, added solvent, and application place. Grossly, you can expect oil-oriented gloss polyurethane spray to last several more years, crossing the 10-year benchmark. Pigments and flattening agents inside the Satin oil finishes disable driers and decay the finish sooner, and they last up to 10 years. Water-based spray coatings have an average of 3-year lifespan, which may decrease to 1 year or increase up to 5 years.
Do I Have to Thin My Polyurethane Spray?
When you apply liquid polyurethane from containers, you have to thin it using mineral spirits if it is oil-based. Water-based container polys do not require thinning. But how about polyurethane in aerosol form? Easy answer – you do not need to thin any of the canned aerosol spray polyurethanes.
What else to say! We have covered nearly every fundamental fact about polyurethane in aerosol form. The information with an added list of best polyurethane sprays may not be inclusive but will surely help you a lot to decide and get your required spray effortlessly!