The vertical flow
In the coated surface or the line Angle of the grooves, the paint flow.Form coating film thickness uneven, serious as hanging curtain droop, light as beads tear marks.
l hinner volatilizes slowly
l overcoating, such as heavy gun spray
l the spraying distance is too close and the spraying Angle is improper.
l paint viscosity is too low
l air is not circulating, the surrounding air solvent content is too high
l too low
l Choose the appropriate thinner
l coating film must not be overweight, even walking.
l improve the proficiency of spraying operations, control the distance of spraying for large parts 25-30cm, small parts 15-20cm, and move in parallel with the surface.
l strictly control the construction viscosity of paint, usually 18-26 seconds.
l appropriate ventilation to keep the temperature above 10 ℃
Produced in the dry film projection, the particle distribution on the whole or partial surface, usually called GeDa, small said "heat rash", some are very small (tip) particle size distribution, and luster。
l The surrounding air is not clean and there is dust in the coating room.
l The paint doesn't filter well.
l The painted surface is not clean
l Keep the air in the room clean and free of dust.
l After the coating is matched, it must be filtered before spraying.
l Clean the coated surface and dust until clean
When besmear face lacquer appears besmear, layer is bitten off, show furrow bulge phenomenon more.
l Apply a coat of paint before it dries
l The solvent of l surface paint can dissolve swelling primer
l The l bottom coating should be dry through and painted on the surface.
l surface paint with weak solvent
The paint film becomes white fog shape, serious loss of light, there are microholes and silks on the film, but sometimes in the drying process will be restored to the original appearance
n in air temperature and humidity is too big, more than the ratio of solvent is diluted by water, or in the process of drying due to solvent evaporation coating surface temperature drops, the surface air temperature will be below the "dew point", the moisture in the air condenses infiltration, emulsion surface into a translucent white film, with moisture to evaporate finally, replaced by the air gap will be perforated matt coating.
l coating field environment temperature is best in 15 to 25 ℃, relative humidity should not be greater than 70%.
l The diluted and compressed air used by l shall be checked for purity and moisture.