What sealing process should be used at the joint of the lighting ready board body for the dusty scenes in rural Africa? Install sealing strips or apply sealant?

Complete solution for splicing and sealing of ready boards in dusty scenes in rural Africa

1、 Conclusion first (distinguishing between two types of splicing processes)

1. Fixed sheet metal joint of the box body (welding/assembling dead joints for side panels, bottom panels, and box frame, not open)

Main process: continuous full welding+external weather resistant silicone sealant filling, without relying solely on sealing strips.

2. Splicing surface of openable door panels/access doors (frequent opening and closing, movable joints)

Core: EPDM/silicone foam sealing strip (preferred), sealant is only used for auxiliary reinforcement and cannot replace the sealing strip alone.

2、 Comparison of the advantages and disadvantages of two sealing schemes in dusty environments in Africa

（1） Sealing strip (compatible with movable door seams)

Advantages (adapted to the core needs of high-temperature sand and dust in Africa)

Elastic adaptive gap: Africa has a large temperature difference between day and night (50 ℃+during the day, sudden drop at night), and sheet metal thermal expansion and contraction will produce dynamic gaps of 0.3~1mm; Closed cell foam EPDM/silicone can sustainably compress and rebound, preventing sand and dust from penetrating gaps, and maintaining a stable IP65 complete dust-proof rating.

Anti sand and dust wear, easy maintenance: Long term erosion by wind and sand only damages the surface of the rubber strip. Local operation and maintenance personnel can directly replace the rubber strip in a full circle without dismantling the box; The sealing failure is visually visible and easy to inspect.

Long weather resistance and lifespan: EPDM is UV resistant, ozone resistant, and resistant to strong sunlight in Africa. It is stable outdoors for 5-8 years; Silicone foam compression permanent deformation ≤ 10%, long-term compression does not collapse, and prevents sand and dust from penetrating the channel.

The overlapping effect of maze structure doubles: the box door frame is made with bent maze grooves and double-layer foam sealing strips, which prevent wind and sand from flowing in a straight line, and the effect of dealing with sandstorms is much better than simply gluing.

shortcoming

Only applicable to movable opening and closing surfaces, fixed sheet metal joints cannot be sealed with rubber strips.

（2） Sealing glue (only used for fixing dead seams and reinforcing, cannot be used as a separate door seal)

Shortboard (fatal flaw in African sand and dust environment)

Easy to crack due to thermal expansion and contraction: Ordinary silicone adhesive will crack within 1-2 years, and a large amount of sand and dust will flow into the box along the cracks, causing empty switches, terminal dust accumulation, and short circuits; Repeated erosion by sandstorms will accelerate the pulverization and detachment of colloids.

After failure, it cannot be easily repaired: after the gel solidifies, it adheres to the sheet metal, and cleaning the residual glue is time-consuming. In rural Africa, there is a lack of professional tools, and on-site repair is extremely difficult.

Non elastic buffering: Slight deformation of sheet metal, transportation bumps, and wall vibrations can cause the adhesive to peel off from the sheet metal, forming permanent sand leakage gaps.

Only applicable scenarios remain

The fixed joint seam of the box body after welding, after the weld seam is polished flat, is fully coated with neutral weather resistant silicone sealant on the outer surface for two layers of dust and water prevention, which belongs to auxiliary reinforcement and cannot be used as the only sealing method.

3、 African Rural Sand and Dust Environment Standard Sealing Process (Complete Implementation Plan)

1. Fixed splicing of the box body (side panel, base, and dead joint of the surrounding frame)

Continuous full welding at the sheet metal joint to eliminate basic micro holes;

Smooth the weld seam and apply phosphating and spray coating for corrosion prevention;

Apply outdoor weather resistant neutral silicone sealant on the outer side, with a layer thickness of ≥ 2mm, completely covering the weld seam gap;

Do not apply glue on the inner side to avoid gel delamination caused by condensation inside the box.

2. Door panel/access door movable splicing (dustproof core)

The door frame is stamped with a double-layer maze waterproof and dustproof groove, which blocks the gap caused by wind and sand blowing directly;

Embedded with closed cell EPDM foam sealing strip (square/trapezoidal cross-section, compression capacity of 30%~40%), double fixed with backing adhesive and buckle to prevent the strip from falling off;

The door lock adopts multi-point compression locking buckle to ensure that the entire circle of rubber strip is uniformly compressed without local gaps or sand leakage;

Upgrade plan: Double layer sealing strip (inner and outer), achieving IP66 full dust-proof and zero dust ingress in strong sandstorm environments.

3. Composite strengthening plan for extreme sandstorm areas (Sahara, arid pastoral areas in West Africa)

Apply a thin layer of weather resistant sealant on the inner side of the door rubber strip to assist in bonding and double sealing;

Widen the rainproof and dustproof eaves at the top of the box to reduce wind and sand hitting the door seams directly;

Elevate the installation at the bottom by more than 20cm to prevent dust from entering through the gaps at the bottom;

The cable inlet and outlet are equipped with waterproof gland heads and sealed with sealant to prevent secondary sand and dust channels.

4、 Material selection suggestions (suitable for African climate)

Sealing strip: Priority EPDM foam strip (high cost-effectiveness, resistant to 40-120 ℃); Silicone foam strips (-60~200 ℃, stronger UV resistance) are used in high-temperature exposure areas, and ordinary PVC strips (1-year hardening and cracking) are prohibited.

Sealing glue: Outdoor weather resistant neutral silicone glue must be used, and acidic glass glue (corroding galvanized/spray painted boxes, short-term detachment) cannot be used.

5、 Key Summary

Joint of movable door panel: Sealing strips must be used as the main component, and sealant is only used as an auxiliary. Applying sealant alone cannot resist long-term sand and dust temperature differences;

Box body fixed welding joint: welding+outer sealant filling, no movable structure, no need for adhesive strips;

The minimum protection standard for lighting ready boards in dusty rural areas in Africa is IP65. It relies on a maze structure and foam sealing strips to achieve complete dust prevention, and the sealant only serves as a fixed seam reinforcement.