How to polish the bright surface with sandpaper, emery cloth and abrasive belt?
1. Substrate selection:
High-density fiberboard is preferred, followed by medium-density fiberboard, particleboard and solid wood are not recommended. The use of melamine sheets is still considered to be the density of the fiberboard under the melamine layer. The low density is not recommended. The density of the sheet has a crucial influence on the later collapse. We use the same process of glossy finish on tinplate and MDF, and the resistance to collapse on the tinplate is much better than on the MDF. In addition, the moisture content of the substrate must be controlled between 10% and -12%. Excessive moisture can cause the fiberboard to shrink and expand, which affects the mirror effect of the paint film.
2. Effective closure:
When the moisture content of the substrate reaches the standard, it is effectively and timely closed, and the sealing is closed to the 6 sides to avoid partial exposure to the air, which affects the sealing effect. The use of PE closure is better than the use of PU closure.
3. Batch ash and inlay:
This process must be done after the closure. On the one hand, the ash will seriously affect the effectiveness of the closure, and secondly, the moisture in the pig blood putty generally used in the ash is prevented from penetrating into the MDF. Large defects are best used to fill in with the atomic ash.
4, PE primer when using anti-collapse high quality PE primer:
Do not apply the PE primer too thick at one time, and do the primer as much as possible twice. It’s best to do it once and then polish it. Grinding requirements after the primer is completed: the large plane must be sanded with a belt machine, first polished with 400, and then polished with 600: the general object is first ground with a 320 sandpaper machine, then with a 400 sandpaper machine, and finally Use 600-800 hand grinding.
5, topcoat construction:
1. Environmental requirements for bright topcoat construction: no dust, no pollution. When using air spray, pay attention to the air pressure between 6-8 pressures and dry and clean. When the air pressure is too low, it can not be atomized very well. Even if it is barely leveled, it will feel corrugated after drying.
2. The construction temperature is best between 15 °C and 35 °C, and the relative humidity should be below 75%. The temperature is too high and it is easy to start the scorpion. The low temperature is easy to cause dark bubbles, and the humidity will reduce the gloss.
3. The paint is strictly matched according to the matching requirements. (The addition of thinner must be adjusted according to the actual conditions of the site being coated.)
4. The good paint needs to be filtered twice with a 200 mesh filter cloth. After filtering, it should be allowed to stand for 15 minutes and then used. It should be used within 2 hours. It should not exceed 4 hours.
5, before the topcoat spray, use 800---1000 sandpaper with soot blowing, do not use the hands to directly wipe the dust, do not use scouring pad to deal with. There is sweat on the hands and the scouring pad is going to drop the sand.
6. When the topcoat is sprayed, the amount of oil is slightly larger, the atomization is better, the first shot should be sprayed, and after evenly coating two crosses, whether the board surface is ideal (side light), if necessary, fill the gun in time, after spraying It can be leveled as a mirror in 1 minute.
7. After spraying, it needs to be placed horizontally. Do not move before drying.
6. After the topcoat is sprayed, it can be dried for more than 48 hours.