Primer plus varnish system spray introduction
At present, car owners' requirements for automotive paints are constantly increasing, not only colorful and bright colors, but also clear and bright mirror effect. 的二工序工艺。 At present, automotive coatings generally adopt a two-step process including a linear primer, a silver primer, a pearl primer, and an overcoat varnish . Taking the British IC2K paint second-order operation process as an example, the spraying construction process of this type of paint is specifically explained.
1) Wash the surface of the board with a neutral detergent, and then thoroughly clean it with water. Moisten a P850-14 degreaser (quick-drying) or R850-1402 degreaser (for hot weather) with a cleaning cloth to wipe the work surface to degrease, and then immediately dry with another cleaning cloth.2) If dents, cracks, etc. are found, use P551-1050 putty (atomic ash, which cannot be used on the surface of galvanized iron sheet) or P551-1052 universal putty (which can be used on galvanized iron sheet) to fill and smooth finely.
3) If there are micro-filled pinholes, sandpaper marks and scratches, you can use P551-1059 / 1060 young grain putty to fill. After filling the metal surface, P400 sandpaper is recommended.
4) Take care according to the needs of spraying, apply rigorous tape, and degrease with degreaser.
5) Spray a layer of P565-597 phosphating primer on the bare metal surface (proportion; 1 part of phosphating primer plus 1 part of P275-61 curing agent), and immediately spray two primers.
6) Fill with P565-7612K primer or P565-8802K fast-drying thick film primer, add 4 parts of P210-925 / 6 curing agent and 850-1492 / 32K thinner, and spray 3 layers at a interval of 5%. ~ 10min, and spray the grinding indicator layer to achieve a more perfect grinding effect. Or use P565-7772K super abrasive-free primer or P565-6682K transparent primer 2 parts plus P210-925 / 62K curing agent 1 part plus P850-1492 / 32K thinner 40% volume fraction mixing and spray 2 layers, 5 -10min. After drying, sand thoroughly with P800 water sandpaper.
7) Treatment of topcoat; first remove the dirty water of the car body with air pressure, then replace the paper or tape, then use P850-14 degreaser to remove oil, and finally use a sticky cloth to remove dust.
8) Coating solution ratio: P422 series of silver background, pure background, pearl color, 1 part 2K thinner. The spraying pressure is 0.3 ~ 0.35MPa, and the nozzle diameter is 1.4 ~ 1.6mm.
，如果样板的颜色与原车待修补板面附近的颜色（包括明度、色相等）完全一致，就可以进行正式喷涂施工了。 9) In order to verify the correctness of the color of the base paint, spray plate test can be performed according to the following procedure: spray 2 to 3 layers of base paint on the sample board, flash dry between each layer for 5 minutes; adjust the pressure of the compressed air, the dilution ratio, The formula of the diluent, etc., until the color completely matches the color of the original paint; spray to the full cover on the template, leave it to dry according to the required time, and then spray 2 to 3 layers of clear varnish, leaving a certain amount of flash on each layer. Dry time, after it is dry, compare it with the color on the original car. If the color of the model is completely the same as the color near the surface of the original car to be repaired (including lightness and color), the formal spraying can be carried out.
10) According to the above-mentioned spraying sample process, spray a layer of base paint on the surface to be repaired, and flash dry for 5-10min. Then spray the second layer of base paint with a slightly larger area than the first layer. After flash drying, spray the third layer of base paint with a larger area than the second layer.11) The base paint is generally not sanded. However, if there are certain defects on the surface, such as change points, irregular hue, severe peeling, etc., it is necessary to sand them. You can first use ultra-fine sandpaper to gently scratch those defects. 干净，再根据需要喷涂1~2道底色漆。 Then clean the surface and spray 1 or 2 primers as needed.
12) Varnish ratio: P190-625 to brand varnish 2 parts plus P210-925 / 6 curing agent 1 part plus P850-1492 /
3 5% to 15% of the volume fraction of the diluent is mixed to make it meet the construction requirements.
The spraying pressure is 0.35 ~ 0.4MPa, and the spraying caliber is 1.4 ~ 1.6mm. The thinned varnish is sprayed on the entire board. Generally, spray less than two layers of coating with about medium humidity, and each layer is separated by 10-15min.
，可采用将清漆兑稀体积分数200%后使用。 13) The required for polishing construction on adjacent boards can be used after diluting the varnish with a volume fraction of 200%.
14) Self-drying (20 ° C) for 16h, or bake at 60 ° C for 35min before polishing.
及去除划痕（机械抛光效果更佳），最后用p971-9油蜡作漆膜保护层（也可机械打油蜡）。 15) Use P150 water sandpaper to smooth dust spots or small vertical flow, use P562-32 young wax to remove sandpaper marks (mechanical waxing effect is better), and then use P97l-29 super wax water to surface and remove scratches ( The mechanical polishing effect is better), and finally use p971-9 oil wax as the protective layer of the paint film (mechanical oiling wax can also be used).
Due to the poor adhesion of the coating film on the surface of the coated object or the undercoating layer, scraping the coating film with nails or metal will cause the phenomenon of coating film peeling, which is called peeling. Car paint is easy to peel off ...