the coating process during corrosion-resistant carbon steel pipe coating
The reason for this is :(1)
The matching function of the coating is not good, and the primer and topcoat are not matched.
The coating with strong polar solvent is applied to the surface of the coating made of less polar solvent.
For example, coated with nitrate cotton paint on mellow or oily paint; rosin-
After adding paint, it contains resin film;
The paint is coated with mellow and sour paint;
It is coated with alcohol and acid paint or oil paint such as oxidized rubber paint and polyurethane paint.
The penetration and expansion of the strong solvent on the coating makes the base coating film bite tight. (2)
The coating is not dry enough to cover the next layer.
If the vinyl chlorine paint or varnish is not dry, apply the second layer of paint. (3)
When painted or painted, choose a strong thinner to expand the primer.
For the reasons of the above growth, we may wish to organize the following procedures for prevention and control :(1)
Strict coating with paint instructions.
Common paint of the same type can be used with each other.
Develop different types of coatings to comply with the rules of hard and soft;
Such as primer with strong solvent coating (
Epoxy resin, polyurethane, etc. )
, Top coat with weak dissolved coating (
Chlorine rubber, alcohol, phenol, etc. ).
Paint agent is added to the resin coating film, which is suitable for sub-coating.
If you want to paint, you must choose by polishing control, brushing the filter layer, and then removing the surface leaching slag particles with a clean rag, polishing with sandpaper, and then painting. Large paint. (2)
The paint should be completely dry.
It should be carried out according to the best coating interval, and the shortest coating interval must be reached.
During winter construction, the coating interval may be delayed in order to ensure that the primer is strong.
For a special type of coating, \"wet-on-wet-on-
Wet coating process can be used.
When the first layer is not applied, a layer is applied immediately, which can increase the adhesion of the coating. (3)
The thinner material used in the paint coating shall not exceed 5% of the total coating amount.
The variety should also be fixed during the coating process.
Weak polar thinners must not be used at the bottom layer, and strong polar solvents such as acetone can be used at the top layer coating.
Ester and aromatic solvent with high boiling point. (4)
The first coat should be thinner for defense.
After the paint is completely dry, a second coating must be applied.
Not too much-
One coating, so that the solvent can not evaporate, extend the drying time. (5)
The coating that fails to \"bite to the end\" cannot be restored to cover and make up.
A shovel should be used to bite the bottom of the coating.
Supporting paint and reform.
After the primer is dry, apply the topcoat after the primer is dry.