Remove any dirt, dust, or road grime accumulated on the vent and the corresponding vehicle structure. These contaminants can create gaps in the weld and reduce its strength. Use a mild detergent solution or specialized automotive surface cleaner, followed by thorough rinsing to eliminate residue. Dry surfaces completely to avoid moisture being trapped during welding.

Address any oil, grease, or wax present on the surfaces. These substances are highly flammable and can burn during welding, producing fumes that weaken the weld and create defects. Use a degreaser designed for automotive materials—compatible with both the vent's material and the vehicle's structure. Gentle scrubbing with a non-abrasive pad may be required, followed by complete drying.

Remove oxidation, rust, or corrosion from metal surfaces. Oxidation forms a thin, brittle layer that acts as a barrier between the weld and the base material, preventing proper fusion. Use a wire brush, sandpaper, or abrasive pad to gently scrape away this layer, revealing clean, bare metal. Take care not to scratch or damage the surface excessively.

Check and adjust the surface flatness. Uneven surfaces can lead to inconsistent weld gaps, which affect weld quality. If the vent or vehicle structure has slight irregularities, smooth them out using a file or fine-grit sandpaper. Ensuring both surfaces are flat and properly aligned helps create a uniform weld joint that distributes stress evenly.

Verify the compatibility of the vent's material with the vehicle's structure. Confirm that the materials can be welded together effectively to ensure preparation steps align with the welding process. Surface preparation methods must match the material's properties to avoid damage or poor weld adhesion.