What surface treatment process should be used for the outer shell of rural lighting ready boards in Africa? Spray painting, spray painting or dipping?

Conclusion on Surface Treatment Selection of African Rural Lighting Ready Board Shell

Recommended with three priority levels: sufficient budget for extreme environments and immersion molding; Mainstream bulk export selects outdoor polyester electrostatic spraying; Spray painting is only allowed for temporary and simple boxes, and it is strictly prohibited for the main force to use in bulk

Typical severe working conditions in African rural areas: strong ultraviolet exposure, alternating dry and wet rainstorm, sand dust impact and abrasion, salt fog in some coastal/low-lying areas, no special personnel for maintenance, and serious transportation bumps.

1、 Comparison of core performance of three processes (adapted to African environmental dimensions)

1. Room temperature/low-temperature spray painting (oil-based/water-based baking paint) - not recommended for main products

Coating thickness: 30-60 μ m, thin, with pinhole permeable channels

Resistant to UV exposure: Poor, Africa experiences 1-2 years of exposure, resulting in extensive powdering, fading, and peeling

Wear resistant and dust resistant: extremely weak, exposed to slight bumps and sandstorms, quickly spreading rust at damaged areas

Salt spray anti-corrosion: only 100-200 hours, rusting occurs in humid rainy seasons and coastal areas within six months

Cost: The lowest unit price, but the repair and after-sales costs are extremely high

Applicable: Short term temporary construction site simple box, not suitable for long-term outdoor lighting ready board export to Africa

2. Electrostatic spraying (outdoor polyester powder spraying, optimal mainstream solution) - preferred for large-scale standard exports

Matching core advantages with African rural areas:

Coating 60-120 μ m, dense solvent-free, UV resistant, outdoor polyester powder resistant to sun exposure for 5-8 years without severe powdering

High hardness, resistant to wind and sand polishing, short distance transportation collision, far superior to spray painting

The cabinet body is bent, the door lock, and the edges and corners of the openings are evenly covered, and the sheet metal ready board has extremely strong adaptability for processing (there are blind spots for deep cavities and small openings covered by plastic immersion)

Rich colors (gray, yellow warning color, black), smooth appearance, in line with the appearance requirements of power equipment

The powder is recyclable, the cost of large-scale production is controllable, and the delivery efficiency is high

Salt spray can last for 500-800 hours, meeting the needs of rainy and mildly saline alkali rural environments in inland Africa

Shortcomings:

The coating is thinner than the immersion plastic, and the corrosion spreads faster after severe impact and hole breaking; Half the lifespan of coastal areas with high salt spray and perennial waterlogging in low-lying areas

Supporting pre process (mandatory):

Cold rolled steel plate shell is first hot-dip galvanized (zinc layer ≥ 80 μ m), then phosphated/vitrified, and then sprayed with outdoor polyester powder (double-layer composite anti-corrosion, WF2 outdoor anti-corrosion grade)

3. Hot dip molding (PE modified weather resistant immersion molding) - the top of the line solution for extremely harsh African environments

Matching core advantages with extreme rural areas:

Coating thickness of 250-1000 μ m, thick rubber like plastic layer, fully wrapped around welding points, cuts, and folds, with zero protection blind spots

Extremely strong toughness, resistant to stone impact and heavy transportation bumps, with slight dents and coating that is not cracked or permeable

Salt spray resistance ≥ 1000 hours, moisture resistance, acid and alkali resistance, suitable for West African coastal areas, swamps, mining areas, and saline alkali rural areas

Better insulation, lower risk of leakage in humid environments, suitable for simple lighting and distribution scenarios without grounding

Shortcomings:

Production costs and processing cycles are 30% -60% higher than those of spray painting

The small door, lock hole, and narrow inner cavity of the ready board are prone to accumulating plastic powder and hanging. The appearance has a strong graininess, and there are few options for warning colors

The workpiece needs to be preheated at high temperature, and ultra-thin sheet metal is prone to slight deformation

Applicable scenarios:

African coastal fishing villages, long-term waterlogging during the rainy season, surrounding mines, villages on the edge of the Sahara with extremely strong sandstorms, and projects with no maintenance and ultra long service (10 years+)

2、 Clear selection criteria for different scenarios

Scenario 1: Ordinary rural areas in inland Africa (high temperature, heavy rain, no salt spray, conventional sand and dust)

Preferred: Hot dip galvanized substrate+outdoor polyester electrostatic spray coating

Cost effective, weather resistant, and balanced mass production, it is a universal and mature solution for exporting photovoltaic/lighting ready boards to Africa domestically.

Scenario 2: Coastal areas in Africa, low-lying swamps, saline alkali zones, and rural mining areas (high salt spray and high corrosion)

Preferred: Hot dip galvanized substrate+weather resistant PE dipping

Thick plastic layer isolates chloride ions, significantly reducing on-site corrosion and after-sales service.

Scenario 3: Low cost and simple temporary lighting ready board (short-term use 1-3 years)

Epoxy zinc rich primer+outdoor polyurethane spray paint can be used, and long-term bulk export is not recommended.

3、 Key process hard technical requirements (must be marked for export to Africa)

Spray painted version

Powder: Outdoor weather resistant polyester powder (including UV stabilizer), prohibited epoxy indoor powder (cracking after half a year of exposure to sunlight)

Coating thickness: ≥ 80 μ m, no red rust after 500 hours of neutral salt spray

Substrate pretreatment: acid pickling and phosphating+hot-dip galvanizing as a base, direct spraying of bare board is prohibited

Immersion style

Powder: Modified weather resistant PE dipping powder, added with anti UV additives, prohibited from ordinary PVC dipping (2-3 years powdering)

Coating thickness: ≥ 300 μ m, salt spray ≥ 1000h

Key points for unified avoidance of pitfalls

It is prohibited to use spray paint alone as the main protection for the shell;

Pure epoxy spray coating has extremely poor UV resistance and cannot be used outdoors in Africa;

Carbon steel box without galvanized substrate, regardless of spray coating/immersion coating, the service life is directly halved.

Simplified Summary

The vast majority of rural lighting ready boards in Africa: hot-dip galvanized+outdoor polyester spray painted (optimal comprehensive and preferred for mass production)

Coastal/saline alkali/severely corroded areas: hot-dip galvanizing+weather resistant PE dipping (long-term top configuration)

Spray painting is only for short-term temporary use and is not a major export process.