How to spray PU for detailed wood in 7 standard steps

PU paint is the perfect alternative to traditional varnish polish. Today, up to 80-85% of handicrafts and wooden furniture use this modern and advanced spray technology to improve aesthetics, create a more luxurious and classy beauty. So how to spray PU for wood to bring high efficiency and ensure the product's as-new durability? What standards does this process need to meet? Hong Ky Mechanical will immediately answer your questions in the article below.

Instructions on how to prepare PU paint

Paint PU means Polyurethane. They exist in hard and foam form for the purpose of polishing, protecting and creating more eye-catching colors for interior and exterior furniture made from natural wood, industrial wood.

Before applying PU spray for wood, users need to prepare paint according to the following steps:
Step 1: Mix primer

Primer has the effect of covering defects, smoothing the wood surface, making the paint color more durable and beautiful. When mixing, you need to follow the instructions on the product packaging with the ratio of 2 lining + 3 gasoline + 1 hard.
Step 2: Mix paint colors

Paint color will help the color of the furniture to be more beautiful and eye-catching, commonly applied to industrial wood. If using natural wood furniture, you should choose a light color, as close to the actual color of the wood as possible.

Depending on needs and preferences, the color ratio is mixed as follows: 1 hard + 5 gasoline + fine color. In particular, the color can be increased or decreased depending on the color of the wood as well as the aesthetic taste of each person.
Step 3: Mix polish

The purpose of using glossy paint is to create gloss, anti-fouling and a more eye-catching effect when light shines on. Gives old furniture a like-new feel.

You make the phase in the ratio: 1 hard + gasoline + 2 balls. The amount of gasoline will increase / decrease to create a matte or bold shade depending on preference.
How to spray PU paint for wood

The PU coating process needs to be ensured to bring high aesthetics to wooden furniture and exteriors

To have a beautiful, shiny and luxurious wooden furniture, PU coating plays an extremely important role. This stage should be performed by experienced and skilled workers to ensure maximum aesthetics.

PU injection instructions are conducted sequentially and follow the following steps:
Step 1: Sanding, surface treatment

This is an important round step that plays a role in preparing and helping the next steps in how to spray PU for wood easily and with better quality. Sanding needs to be careful, giving a smooth feeling, removing rough defects, surface holes.

Accordingly, depending on the need to paint or leave the wood grain intact, the worker will choose putty or not. However, according to the experience of Dong Ky Mechanics, when painting PU, it is best to choose glossy surface paint.

Should choose putty is black or brown powder to fill nail holes, defects affecting aesthetics. If you skip this step, when painting you will spend a lot of material on areas with gaps and holes.
Step 2: How to spray PU for wood - Adjust wood color

Wood surface always has color heterogeneity, this is inevitable when using natural wood in furniture processing and manufacturing. In contrast, with artificial woods, the color is relatively harmonious so you can also skip this step.

Simply put, background retouching is applying a layer of color similar to the natural color to create uniformity. The mixing formula will depend on the type and color of each different wood. It requires the operator to have experience and high skill.
Step 3: Primer 1st and 2nd time

Use colorless paint in the ratio of 2 PU + 3 gasoline + 1 hard to form a primer. In fact, you can reduce or add other additives to increase the volatility of the paint. Especially in hot weather conditions, low humidity in the air, fast evaporation rate can cause the paint surface to bubble, have ripples, take a lot of time and effort to repair.

Note, after each paint, it is necessary to sand, fill and seal the defects on the surface, and then add a primer for each coating. In case the putty step is done carefully, eliminating holes, you only need to do 1 coat of primer to save money on materials and construction time.
Step 4: How to spray PU for wood - Paint color for the 1st time

In order for the paint color not to be too dark or uneven, at the first time you paint, you only need to apply about 90% of the color as mixed. The formula is as follows: 1 hard + 5 gasoline + refined color. This step should be done by a professional worker, to avoid the error of not reaching the desired color. Wait about 5-10 minutes for the paint to stabilize before you can proceed to the next step.
Step 5: Paint the second color

The second paint color needs to be more compact and 100% guaranteed

At the second time, you can follow 100% of the required color. This time, the paint will be darker and focus on treating the areas that are lacking or light.

This stage needs to be done carefully and meticulously because it determines 80% of the quality of the PU coating process. At the same time, it should be done in cool, clean spaces, where you can clean up dust so that painting is done more conveniently and easily.
Step 6: Primer for the 3rd time (if needed)

In this step, you only need to apply the paint thin enough to help increase color fastness and limit peeling during use. Incorporate sanding to completely remove residual imperfections.

At this step, the surface finish and smoothness must reach 100%. Carry out a final thorough check to avoid any omissions before injecting the ball.
Step 7: Spray gloss (top coat)

Depending on the paint model and type, you can choose gloss levels from 10 or even 30 and the highest is 90. In which, gloss 10, 20 and 80, 90 will be more expensive than the middle grade. , so you should consider when choosing.

The general formula for mixing polish is 1 hard + gasoline + 2 balls. However, the amount of gasoline can be reduced and added some other additives to suit weather conditions. They will help slow down the evaporation rate of the paint, thereby overcoming the foaming or blurred paint film caused by saturation of water vapor on the surface at times of fog or early morning, late at night...

How to spray PU for wood includes 7 standard steps. This process is applied to all furniture made from wood such as kitchen cabinets, wardrobes, desks, doors, windows...