What kind of paint is used for the guardrail? What is the general spraying method?

2. Apply topcoat. The topcoat is determined according to your specific needs.

Process flow:

Inspect the substrate-sandblasting, derusting-coating zinc-rich primer-drying-polishing-coating epoxy micaceous iron primer-drying-polishing-putty repair-drying-polishing-quality inspection-topcoat spraying-coating drying-testing.

Sandblasting and derusting can be used for:

A: derusting by sandblasting or shot blasting to Sa2.5 level; B: Use 120# iron sandpaper to polish to St3 grade; C: pickling d: rusty primer.

Spraying zinc-rich primer:

① Configuration of zinc-rich primer

A: stir the original paint evenly: after the original paint is fully stirred, pour it into a paint mixing tank;

B: selection of diluent: according to the technical requirements of the coating;

C: Addition amount of curing agent: determined according to coating type and construction method (10:1);

D: adjustment of viscosity: the temperature is determined, and the amount of diluent added is about 40%;

E: blending and filtering with 150 mesh;

F: Clean the tool with general thinner immediately after use.

② Spraying requirements

A: spray for 2-3 times, with an interval of 10- 15 minutes;

B: The coating is uniform, and there are no defects such as sagging and rebar exposure;

C: dry film thickness of primer: 50-70um.

Dry at room temperature for more than 4 hours, and polish with 400-600 mesh sandpaper until the surface is smooth, particle-free, smooth and free from ash and other pollutants; Clean up the floating ash for later use.

Spraying epoxy micaceous iron primer:

A: stir the original paint evenly: after the original paint is fully stirred, pour it into a paint mixing tank;

B: selection of diluent: according to the technical requirements of the coating;

C: Addition amount of curing agent: determined according to coating type and construction method (7:1);

D: Adjustment of viscosity: for temperature measurement, the adding amount of diluent is about 40%.

② Spraying requirements

A: spray for 2-3 times with an interval of 10 ~ 15 minutes;

B: The coating is uniform, and there are no defects such as sagging and rebar exposure;

C: dry film thickness of primer: 50-70um.

Process specification

A: Use 360# or 600# sandpaper to polish until the surface is smooth;

B: There are no particles, dust and other pollutants on the surface.

Putty repair:

Preparation of putty: according to the instructions;

Find out the unevenness or defects;

Manual repair with scraper, generally batch coating for 2 ~ 3 times until the defective parts are completely filled;

Putty repair layer should be thin, without leakage, smoothness and scratches;

If the requirements for surface flatness are not high, or the base surface itself is relatively flat, it is not necessary.

Polishing with 600# or 800# sandpaper until the surface is smooth;

The surface is free of particles, smoothness, dust and other pollutants;

The edges should be feathered to ensure that there are no obvious seam marks after painting.

Primer spraying (intermediate coating)

Correct selection of primer (BC-S 100) according to the scheme.

Prepare primer (weight ratio BC-S 100: G2: X- 160 (X-170 in summer) =100:10 ~ 40).

A: stir the original paint evenly: after the original paint is fully stirred, pour it into a paint mixing tank;

B: Selection of diluent: according to the technical conditions of the coating (X- 160, X-170 in summer);

C: Addition amount of curing agent: determined according to coating type and construction method (G2);

D: Adjustment of viscosity: determination of temperature and diluent addition (viscosity measured by coating -4 cups is between 17-2 1);

E: filtering after blending: selecting the corresponding screen size (250 mesh) according to the type of paint;

F: when the air temperature >; 5℃, air humidity 75% or less weather construction;

G: avoid working before it rains and in windy weather;

H: Generally speaking, the mixture must be used up within 4 hours;

I: Avoid rain erosion during construction and within 24 hours after completion;

J: Clean the tool with general thinner immediately after use.

K: 5 ~ 10 min leveling, dry surface.

Spraying requirements:

Answer: If the top coat is a color with poor hiding power, it should be matched with a solid primer (medium coat) with similar color;

B: Uniform, without sag, exposed bottom, shrinkage cavity, hair flower and other defects;

C: the coating thickness is 8 ~ 12um.

3.5 Top coat spraying

Correct selection of topcoat (FC-S200) according to the scheme.

Preparation of topcoat (weight ratio FC-S200: G2: X- 160 (X-170 in summer) =100:10:10 ~ 40)

A: stir the original paint evenly: after the original paint is fully stirred, pour it into a paint mixing tank;

B: Selection of diluent: according to the technical conditions of the coating (X- 160, X-170 in summer);

C: Addition amount of curing agent: determined according to coating type and construction method (G2);

D: Adjustment of viscosity: determination of temperature and diluent addition (viscosity measured by coating -4 cups is between 17-2 1);

E: filtration after blending: select the corresponding screen size (solid color 250 mesh, metallic color 180 mesh filtration) according to the type of paint;

F: when the air temperature >; 5℃, air humidity ≤ 75%;

G: avoid working before it rains and in windy weather;

H: Generally speaking, the mixture must be used up within 4 hours;

I: Avoid rain erosion during construction and within 24 hours after completion;

J: Clean the tool with universal thinner immediately after use;

K: 5 ~ 10 min leveling, dry surface.

Spraying requirements:

Answer: Other types of topcoats that can be cured at room temperature can also be selected, such as BC-S90 and FC-S202.

B: The coating is uniform, and there are no defects such as sagging, exposed bottom, shrinkage cavity and hairiness;

C: the coating thickness is 20 ~ 30um.

3.6 Top coat spraying

Correct selection of topcoat (FC-S250) according to the scheme.

Preparation of topcoat (weight ratio FC-S250: G2: X- 160 (x-170 in summer) =100:10:10 ~.

A: stir the original paint evenly: after the original paint is fully stirred, pour it into a paint mixing tank;

B: Selection of diluent: according to the technical conditions of the coating (X- 160, X-170 in summer);

C: Addition amount of curing agent: determined according to coating type and construction method (G2);

D: Adjustment of viscosity: determination of temperature and diluent addition (viscosity measured by coating -4 cups is between 17-2 1);

E: filtration after blending: select the corresponding screen size (350 mesh filtration) according to the type of paint;

F: when the air temperature >; 5℃, air humidity 75% or less weather construction;

G: avoid working before it rains and in windy weather;

H: Generally speaking, the mixture must be used up within 4 hours;

I: Avoid rain erosion during construction and within 24 hours after completion;

J: Clean the tool with universal thinner immediately after use;

K: 5 ~ 10 min leveling, dry surface.

Spraying requirements:

Answer: If the topcoat is aluminum paint, it should be matched with topcoat, or other types that can be cured at room temperature, such as BC-S950, FC-S252, etc.

B: The coating is uniform, and there are no defects such as sagging, exposed bottom, shrinkage cavity and hairiness;

C: the coating thickness is 10 ~ 15um.

4 coating drying

4. 1 drying method

Bake at 100℃ for 60 minutes and cool to normal temperature.

Drying at normal temperature for more than 7 days.

4.2 Drying requirements

When baking and curing, the oven should be kept clean;

Large workpieces and special workpieces are suitable for air drying at room temperature.

5 check

Inspectors should visually check the surface condition of the coating, whether there are defects such as sag, exposed bottom, shrinkage cavity, hairiness, bubbles, particles, cracks, etc. , are unqualified products, and then go back to the polishing process to polish the whole top coat with 600 mesh sandpaper. After blowing, the whole board is sprayed with top coat again. Require one-by-one inspection;

The inspector shall inspect the performance index of the coating according to the inspection specifications. 5%- 10% for each batch of inspection, and double the quantity for reinspection if unqualified; If the reinspection is still unqualified, it can be partially or completely reworked according to the specific situation.