You need to make all kinds of preparations before drawing wood. The preparation of wood paint construction mainly includes three aspects: material preparation, tool preparation and working environment. Let's take a look at the preparatory work to be done before painting wood paint.
1, material preparation
The main materials used in the construction of wood lacquer are wood putty and wood lacquer. Commonly used wood paints include nitrocellulose paint, polyurethane paint and waterborne wood paint.
Wood putty can fill the seams, scars, nail holes and other defects on the wood surface, save material and labor when painting wood, improve the smoothness of the paint surface and increase the aesthetic feeling of the wood surface.
Comparison of main varieties of wood lacquer
Nitrocellulose paint (NC) has good decorative effect; Fast drying speed; Easier repair and lower solid content; Durability, gloss retention and color retention are not good; Poor environmental protection.
Polyurethane paint (PE) film is plump and thick, with good gloss and transparency; Hard and wear-resistant, strong adhesion, damaged paint film is not easy to repair; Slow drying speed; The coating film turns yellow easily.
Waterborne wood paint (W) has good environmental protection; No yellowing, excellent water resistance, no combustion; The hardness of antirust and high temperature resistant waterborne coatings is not high; The construction environment requirements are relatively high.
2, tool preparation
Wood lacquer construction needs some tools. Commonly used tools include sandpaper, filter, brush, emery cloth, spray gun, roller brush, etc.
Sandpaper is used to polish the wood surface, and the filter screen is used to filter the impurities in the wood paint. According to different brushing methods, tools such as brushes and spray guns can be selected.
3. Working environment
The construction of wood coatings is a very precise and meticulous work, which requires suitable environmental conditions. Only when the temperature, humidity, light, ventilation and hygiene meet certain requirements can a good paint effect be achieved.
Temperature: It is best to carry out at normal temperature (15-30℃). If the temperature is too low, the paint film will slow down. If the temperature is too high (over 35℃), the brushing performance will be adversely affected.
Humidity: Avoid humid air, which is not good for most paints, especially nitrocellulose and polyurethane paints. Construction in wet and rainy weather will cause some disadvantages such as whitening or slow drying.
Light: Sufficient light helps to see the surface of varnish clearly, distinguish whether the coating is uniform or not, and avoid brush leakage or sagging in time, so the construction should be carried out in a well-lit room.
Ventilation: The construction site should be equipped with ventilation equipment to maintain proper fresh air circulation. This is not only beneficial to the health of construction workers, but also beneficial to the film formation of coatings, and can reduce fire hazards. However, the speed of air circulation should not be too fast, so as not to affect the coating quality.
Hygiene: the construction environment must be kept clean, and the dust and sundries generated in the construction process should be removed in time, otherwise the final effect of the topcoat film will be affected. Clean construction environment is particularly important when painting floor paint.
Second, the wood paint coating process
Wood coatings have three effects: closed, semi-closed and open. The closed effect is to completely cover the wood grain, and the open effect is to show the natural texture of wood. According to the different effects, the construction methods of wood paint are also different.
In addition, there are mainly three kinds of wood paints: nitrocellulose paint, polyurethane paint and water-based wood paint. Due to the different composition of products, their construction methods are also different. There are many construction methods of wood paint, and it is best to choose the appropriate construction method according to the desired coating effect and the products you choose. In fact, there is not much difference between various construction methods, which may be the difference between sequence and brushing. The following are some basic practices of wood paint construction.
1, plate processing
Before painting, clean the wood and wipe off the dust on the wood surface. Special dusting cloth can be used when cleaning, and large areas such as floors can be vacuumed repeatedly with a vacuum cleaner. At the same time, use sandpaper to polish the board surface or wood line surface, and pay attention to protect the veneer to avoid being worn through by sand.
The purpose of plate treatment is to effectively remove stains, wood hairs and wood thorns on the plate, make the surface of the plate clean and smooth, and make the subsequent painting labor-saving and material-saving effect good.
2. The plate is closed
The prepared special sealing agent is evenly coated on the board, which can effectively seal the board and prevent the board from being polluted.
Sealing plate can prevent excessive moisture absorption, moisture dissipation and plate deformation, enhance the adhesion between paint film and plate, save paint dosage and enhance the hardness of paint film.
3, blow be bored with child
Select the matching wood putty, mix it and scrape it on the wood eye. After the putty is dry, use sandpaper to polish it, and thoroughly clean the putty on the wooden tools.
Filling wood holes with putty can reduce the amount of wood paint and improve the smoothness of paint film. Different painting effects have different requirements for putty scraping. For example, to achieve the opening effect, the putty color should be adjusted to be consistent with the color of the plate before scraping.
4, primer construction
Adjust the wood primer according to the required proportion, and brush or spray it. The function of primer construction is to fill holes in wood and increase the thickness of paint film.
Pay attention to the primer during construction. After the primer is dry, it must be thoroughly polished with sandpaper before applying the primer. It is required to brush evenly, without sagging, and the wooden eye should be filled evenly.
5. Polishing treatment
Sandpaper is actually a step that runs through the whole process of wood paint construction. Plate treatment, putty scraping, primer construction and topcoat construction need sanding. The grinding step is very important.
Sanding treatment makes the plate smoother and smoother, which is beneficial to painting. After painting, sanding makes the surface of paint film smooth. But be careful to avoid horizontal sand when grinding, and don't use coarse sandpaper to grind.
6, topcoat construction
Before topcoat construction, the wood surface must be cleaned again to remove dust particles, so that the paint film surface can have better painting effect. Every time the top coat is brushed, it is not advisable to brush it too thick at a time. It's best to brush it several times, and then do the next layer of construction when the paint film is dry.
Topcoat construction directly affects the final effect of paint film. Top coat construction requires uniform painting, no sag, good gloss, no obvious brush marks and smooth and delicate hand feel.