What corrosion protection is applied after structural repairs?

• A. Weld-through primer, seam sealer, and cavity wax
• B. Primer only
• C. Clear coat
• D. Undercoating

Answer: (A)

After structural repairs, protecting exposed metal from moisture and salt at welds, seams, and inside hollow sections is essential to prevent rust. The best approach is to use a combination: weld-through primer to guard the welded areas from corrosion as a primer is applied before finishing, seam sealer to seal joints and prevent water and air from penetrating gaps, and cavity wax to coat interior hollow spaces that can’t be reached after assembly. This trio provides a continuous barrier: primer protects the welds, sealer blocks moisture at seams, and wax protects hidden cavities. Using only a primer would leave seams and inner areas vulnerable; a clear coat is a cosmetic topcoat and doesn’t provide corrosion protection, and undercoating is typically used on the underside and doesn’t address interior cavities or welded seams in the repaired area.