Varnish spraying, what you must know

1. What is varnish?

Automotive varnish is generally used in conjunction with one-component base paint. After spraying the base paint, then spray varnish, commonly known as overcoat varnish or varnish, to provide protection and decorative effects for the base paint. The varnish has high gloss and UV resistance and other properties. .

2. What is the situation of varnish with medium concentration and high concentration?

Due to the difference of varnish resin and solid content, it can be divided into medium-concentration varnish and high-concentration varnish. The names of varnishes from different manufacturers may be different, but they are all divided according to solid content. The higher the concentration, the higher the price, the better the hardness and the gloss. The performance in all aspects is also better, (note: the concentration is not the consistency of varnish that everyone usually thinks, but the level of solid content). Varnishes with different concentrations need to be matched with corresponding curing agents, that is, medium concentration should be equipped with medium concentration curing agent, and high concentration should be equipped with high concentration curing agent.

3. What is the ratio of curing agent and thinner?

The ratio of varnish and curing agent of most brands is 2:1, and there are also 3:1 and 4:1. Please strictly abide by the manufacturer's requirements. Thinner ratio: each brand is different, environmentally friendly varnish usually does not add thinner or adds a small amount of thinner, usually the ratio is between 5% and 25%, please strictly abide by the requirements of each brand.

Please don't just pour it by feeling. It is more accurate to use an electronic scale or measuring cup. If you really can't find a disposable plastic cup to measure it, it is much better than pouring it by hand, because your feeling is not always so accurate! ! !

4. What will happen if the ratio of curing agent and diluent is incorrect

The amount of curing agent added should be strictly in accordance with the requirements of the manufacturer. If too much curing agent is added, the paint film will become brittle, easy to crack after collision, and the toughness will be reduced. If you add too little, the drying speed of the varnish will be slow or not dry, the hardness will be reduced, and the gloss will be poor; the amount of the thinner should not be too much or too little, too much will cause the varnish to lose its gloss seriously, the spraying is easy to sag, and too little will cause the varnish to flow. The leveling is not good, the paint film is uneven, orange peel appears, and the paint film effect is not ideal.

5. In order to spray the varnish well, you need to pay attention to the following matters

Whether the traditional car varnish is sprayed well or not, the primer layer is the key. If the primer layer is sprayed rough, uneven, and poorly dried, no matter how good the varnish is sprayed, it is a waste. The spraying of varnish is generally 2 to 3 times, and after the proportion is prepared according to the manufacturer:

(1). Use semi-dry and wet spraying for the first time, do not spray too thick or bright, and then spray the second time at an interval of about 5 to 10 minutes (depending on the ambient temperature).

(2). Wet spray is used for the second time, and the speed is slightly slower to go evenly. The sprayed effect looks thick and smooth, and the brightness is high. Check the flatness and fullness of the paint film. If you feel that the brightness cannot be achieved, spray it a third time, and pay attention to the problem of sagging. High-concentration varnish is generally two times to achieve the effect.

(3). In addition, it is necessary to pay attention to adjusting the distance, spray width and air pressure of the spray gun, depending on the different spray guns and methods.

6. Is the hardness of your varnish good?

Most of the traditional varnishes on the market have a solid drying time of 7 days to 15 days without baking, which means that the hardness of the varnish is the best at this time. Baking at 60 degrees for 60 to 70 minutes can also achieve the best hardness. So don't spray the paint and do not bake the next day and think the hardness is very high.

Also, don't use your nails to test the hardness of the varnish, because everyone's nails are different in hardness and strength, and the results will be different.