14 Dec Pro Tips for Applying Polyurethane
Polyurethane is a protective topcoat that is colourless and resistant to moisture, scratches and UV. It creates a tough layer over your paint that can withstand bashes and scrapes for a long-lasting finish.
However, applying polyurethane isn’t the simplest of procedures. Drying conditions need to be perfect, as do the tools you need to use to ensure a smooth and clear coating.
Here are some pro tips to make sure you get the job done right.
Pick the correct product
A polyurethane coating is useful when it comes to painting furniture, staining wood or painting a high-traffic surface. You therefore need to pick a product that’s right for what you’re working on, especially if it stays outdoors.
Once you’ve established this baseline, you’ll need to choose between oil-based and water-based polyurethane. In general, water-based is best, even though it can be more expensive. It will have fewer volatile organic compounds (VOCs) than the oil-based version and can be cleaned with water, rather than chemicals. It is also not flammable.
Water-based polyurethane dries quickly but does require more application coats, whereas the thicker oil-based polyurethane needs fewer coats and costs a little less, while requiring a longer drying time.
Create a safe space for painting
It’s important to work in a well-ventilated, covered area when applying polyurethane. Opening doors and windows is useful, as is using an air purifier. Avoid the temptation of working outdoors, however, as dust, pollen and insects could mar the surface of what you’re painting.
Prepare your work area
If you’re applying polyurethane to a piece of furniture, prepare a clean, dust-free surface to work on. Ensure the surface is flat to limit the chances of the polyurethane dripping while it dries.
Try and avoid sanding the piece so that you keep the colour true. The best way to prep the furniture is to wipe the wood with a rag dampened with a solvent such as methylated spirits, which will clean the grain and remove dust.
Work with the grain
Whether you’re applying polyurethane to wood or a pre-painted surface, try work in the same direction as the wood grain or the previous direction of the paint brush or roller. Don’t apply the polyurethane too thick and make sure you brush out bubbles while you’re working. Keep a rag handy to wipe up drips if you’re working on a slanted surface.
Once the first coat has dried, sand the surface lightly, wipe off the dust and apply more coats as needed. Sanding between coats is important to help each new coat adhere properly. Just make sure you don’t sand the final coat, as this will ruin the smooth finish you’re after.
To ensure the polyurethane is dry before reapplying, you’ll need to wait for about 4 to 6 hours, depending on if you’re using an oil- or water-based product. Water-based will dry quicker, however if the weather is humid, it’ll be best to wait a little longer. You should also find the manufacturer’s drying-time guidelines on the tin itself.
Leave the polyurethane to the pros
If the aforementioned steps feel a little too complex and time consuming, give Pelham Painters in Hobart a call. We have the knowledge you need to pick the right product, do the correct preparation and create the perfect polyurethane finish.