Polycrylic vs. polyurethane
Many still consider that polycrylic and polyurethane are the same sealer coat. Despite their similar function as wood protectors, they have several differences.
Polyurethane is available in oil-based, water-based, and combinations. Meanwhile, polycrilic is water-based only and can be applied in the form of spray-on or aerosol and roll-on.
Brushing polycrylic is hard as it is impossible to have a brush-strokes-free finish. Just like water-based polyurethane, spraying polycrylic is the most recommended method.
As a result, polyurethane has a thicker and more durable layer to protect the wood.
The finish looks after spraying polycrylic
Based on its types, polycrylic has several sheen choices as the finish. They include ultra-flat, satin, semi-gloss, gloss, and matter.
In the can, it is milky white. Once you apply it to wood, it dries clear and transparent. Most polycrylic finish-looks have a crystal-clear layer without extra color.
Hence this coat is great if you want to show off the raw wood grain or pattern. Light woods have a better finish than dark ones.
Furthermore, applying it over paint or stained wood helps to bring out the color. Complete the final look without strokes and uneven surfaces by spraying polycrylic.
Furniture that works well with polycrylic
As mentioned before that polycrylic dries faster with a clear finish but is less durable. Because of its criteria, the coat is good for indoors that experience less wear, water, and heat.
Moreover, it is easy to work on small objects and horizontal surfaces. Its protective properties are good for home décor projects, side tables, decorative trays, cabinetry, and more.
In addition, polycrylic is less toxic than other varnishes making it safe for interior furniture.
In contrast, some woodwork like bench, floor, porch, gate, and other exteriors or furniture that experience wear and tear are not recommended to have this coat. Spraying polycrylic might dry fast, but it gets thinned fast too.
Woods that work well and not with polycrylic
As polycrylic is water-based, oily woods absorb the liquid very slowly. It is good for the appearance of light color paints like white and light wood such as maple wood, birch, white oak, red oak, hickory, etc.
It will dry without a yellow tint. On the other hand, dark-color woods or woods with dark paint will have a milky or opaque finish after being applied with polycrylic.
The dark woods include walnut, teak, mahogany, rosewood, and others.
Preparation before spraying polycrylic
Preparation should include the workplace, woods, and sprayer/tool. Many prefer to spray it outdoors or in a room with clear air ventilation.
Though it is odorless compared to polyurethane, the odor still takes time to disappear in a room. Then check the wood and sand the surface.
Fix any cracks and dents (if any) since any flaws are still visible under polycrylic. Tools and materials you might need are polycrylic, water as thinner, sprayer, 80 or 100 grit sandpaper for a start, and 120 or 150 grit sandpaper for the finish.
Using a spray gun with high velocity will not make adhesion but only spatters. Check whether the polycrylic you use requires thinning because some brands do not. If it needs, adds water for about 10% of polycrylic volume.
Steps of spraying polycrylic
- As mentioned before, prepare the tools, materials, and workplace before spraying polycrylic. Sand the wood. Check the cleanness of the sprayer and the polycrylic brand’s instructions whether it needs 10% thinning to the liquid.
- Add the polycrylic to the sprayer can or cup. You can use a filter when you pour the liquid into the can as it will prevent clumps and bumps.
- Set up the sprayer gun and run a test to see the sprayed result. While testing, you should place your hands comfortably and decide on the right spray pattern.
- Check the test run. If you find any uneven surface, it might be caused by the wrong handling position or spraying techniques.
- Once you get the desired hand position and spraying pattern, it is time to spray.
Spraying polycrylic tips
- Before spraying, check the temperature. Do not spray when it is above 50 degrees. As polycrylic dries so fast, hot temperature makes it dries faster. Instant drying causes textured bumps and makes the surface rough.
- The suggested coats for spraying polycrylic are three. For each layer, you are suggested to sand the surface using 400 grit sandpaper. It helps the coat to stick well over the previous layer.
- The suggested workplace is outdoor, which is dust-free, or if you spray indoors, make sure to have good air circulation. Remaining fogs for minutes after spraying in the room signifies that your room doesn’t have good ventilation.
Spraying polycrylic pros and cons
Pros:
- It is less dangerous and has a less toxic odor. Its VOC is not as high as polyurethane’, so it is less likely to harm the lungs. Moreover, it doesn’t cause flame easily like polyurethane after being sprayed on.
- Among other sealer products, polycrylic has the fastest drying time.
- It costs less pricey compared to other sealers.
Cons:
- Less durable and prone to disappear because of prolonged heat, water, and wear.
- With improper application, the result can have a milky or opaque surface.
- Difficult to apply to big objects, especially those with uneven areas or joints.
Possible causes of failed polycrylic
Before spraying, ensure the current surface is well-sanded to have good adhesion and is flaws-free. Spraying polycrylic won’t fix those problems as it has crystal clear results.
If there are bumps or rough areas, it can be due to an improper previous layer, whether the layer hasn’t been sanded well or paint on the current layer has not been fully set.
Another common cause is when polycrylic is sprayed or applied on more flexible coats like latex.
Removing stains from spraying polycrylic
While spraying polycrylic you may spatter some stains on other objects. Either way, you might want to remove it from the wood surface to add other different sealers.
The easiest way to remove it is by sanding it. White vinegar can help to scrape it off too. Yet dilute it in water first. Acetone can be used too, but it usually leaves off stains on the surface.