1. The humidity of the air. When the relative humidity in the air reaches 85% or the surface temperature of the sandblasted object is less than 3 ℃, sandblasting shall be stopped.
2. Time interval between sand blasting and painting. Generally speaking, paint treatment should be carried out immediately after the use of garnet sand blasting, so that the contact time between the sandblasted object and the air is short, and the dust and moisture content falling on the surface of the workpiece is small, which can maintain excellent sandblasting effect and achieve longer coating life. The excellent time interval between sand blasting and painting is 4 hours. If the paint is not painted for more than 6 hours, the secondary surface treatment must be carried out.
3. Determination of moisture and chloride content of garnet sand. The requirements of sand blasting for the moisture and chloride content of garnet sand are lower than 1%. If the content of both is too high, it is very easy to produce soluble salts.
4. Dust free sand blasting abrasive shall be selected as far as possible. The common fugitive dust during sand blasting is mainly caused by the materials, such as copper slag and quartz sand with light specific gravity, which are easy to produce floating objects, and the possibility of containing free silicon [silicosis]; The second reason is processing. Even the heavy garnet sand, because of rough processing, without fine screening or water washing, has dust in the abrasive, which will also produce dust, which will cause trouble to operators. RZG dust-free garnet abrasive can be selected, which is washed for 6 times, sieved for 4 times, with a specific gravity of 4.0-4.2 and little dust.
