7 Steps Fuselage Skin Grinding Process

Fuselage skin grinding is an important part of the aircraft manufacturing and maintenance process. The following is its general processing process:

Step1: Preparation work

Determine the polishing needs: Determine the degree and target of polishing based on the condition of the fuselage skin, such as surface scratches, oxidation, coating damage, etc.
Select appropriate abrasives: According to the skin material (usually aluminum alloy, composite materials, etc.) and grinding requirements, select the appropriate grinding wheel, sandpaper, abrasive belt or other abrasives, as well as the corresponding abrasive grain size. For example, more severe damage may require initial sanding with coarse-grained abrasives, then gradually transitioning to fine-grained abrasives for fine polishing.
Safety protection: Operators wear appropriate personal protective equipment, such as goggles, gloves, earplugs, etc., to prevent dust, noise and splashes generated during the grinding process from causing harm to the body.

Remove dirt and old coatings: Use detergent or solvent to clean the fuselage skin surface to remove oil, dust and other impurities. For areas with old coating, use chemical paint strippers or mechanical methods (such as scraping, sanding) to remove the old coating in preparation for sanding.
Check surface defects: Before polishing, carefully check the surface defects of the fuselage skin, such as cracks, pits, corrosion, etc., and mark them so that they can be dealt with during the polishing process.

Choose the right grinding tool: Depending on the shape and size of the skin, choose a tool such as a handheld grinder, air grinder, or electric grinder. For large skinned areas, a belt sander can be used for quick sanding.
Preliminary grinding: Use a coarse-grained abrasive tool with appropriate pressure and speed to preliminary grind the fuselage skin. The grinding direction should be consistent with the texture of the skin as much as possible to avoid cross scratches. During the sanding process, constantly observe the surface condition to ensure that all defects and uneven areas are removed.
Clean up the grinding dust: Use a vacuum cleaner or compressed air to clean up the dust generated by grinding in time to avoid dust accumulation that affects the grinding effect and the working environment.

Replace fine-grained abrasives: After rough sanding is completed, replace with fine-grained abrasives and abrasives, such as 240 mesh, 320 mesh or higher grit sandpaper, grinding wheels, etc.
Fine-sanding: Use lighter pressure and slower speed to fine-sand to make the surface of the skin smoother and evener. During the sanding process, attention should be paid to controlling the intensity to avoid over-sanding, which may cause thinning or dents in the skin.
Check surface quality: Continuously check the quality of the skin surface to ensure the required smoothness and flatness are achieved. Inspection can be done by touch, visually or with the help of tools such as a magnifying glass.

Clean the surface: Use a clean rag or compressed air to clean the skin surface again to remove remaining dust and impurities.
Check for surface defects: Conduct a final inspection of the polished skin surface to ensure that there are no missed defects. If you find that there are still uneven or defective areas, you can perform local supplementary sanding.
Coating treatment (optional): As needed, the polished fuselage skin can be coated with coating treatment, such as spraying anti-corrosion paint, primer and topcoat, etc., to protect the skin surface and improve the appearance quality.

Appearance inspection: Conduct an appearance inspection on the polished fuselage skin to ensure that the surface is smooth, without scratches, dents, discoloration and other defects.
Dimensional inspection: Use measuring tools to check the dimensions of the skin to ensure that the polished dimensions meet the design requirements.
Surface roughness inspection: Use a surface roughness meter and other equipment to check the roughness of the skin surface to ensure that it reaches the specified roughness value.

Clean the work area: Clean the grinding tools, abrasives, and other equipment, organize the work area, and keep the environment tidy.
Record the processing process: Record the process and results of the fuselage skin grinding process, including the abrasives used, grinding parameters, quality inspection conditions, etc., to facilitate subsequent quality traceability and process improvement.