Corrosion Protection Guidelines: General Motors

A key factor in collision repair is making long-lasting repairs. When a vehicle is repaired, many areas of corrosion protection are disturbed. This creates corrosion hot spots that left untreated will lead to corrosion and potentially a repair failure. However, there are certain precautions that can be taken to safely and properly restore the corrosion protection throughout the repair process. OEMs often give specifications on restoring corrosion protection. These specifications generally include seam sealer, adhesives, foam fillers, and cavity waxes. Let’s take a look at what General Motors (GM) says.

Information on corrosion protection can be found in the vehicle-specific body repair manuals (BRMs) in: Body Repair ➤ Paint And Coatings ➤ Introduction ➤ Anti-Corrosion Treatment And Repair. GM suggests several products from various manufacturers including: Kent Automotive, Crest Industries, 3M, and Automotive International/Valugard.

GM also specifies when corrosion protection needs to be restored and where it should be applied.

Per the GM Anti-Corrosion Treatment and Repair document:

• “Any procedure that disturbs these special treatments, such as panel replacement or collision damage repair operations, may leave the metal unprotected and result in corrosion. Proper recoating of these surfaces with service-type anti-corrosion material is essential.”
• “The Closed Cavity coatings remain sticky to the touch and will seep into seams initially and over extended periods of time. Closed Cavity coatings provide the best corrosion protection inside of rocker panel sections, pillar sections, frame rails, cross-members, doors, rear compartment lids and closed areas of hoods - anywhere that is concealed or closed off to exterior surfaces.”
• “Sealers are intended to prevent water and dust from entering the vehicle and also are anti-corrosion barriers. Sealers are applied to such areas as rear compartment lid hem flanges, wheelhouse, quarter outer, floor, cowl, roof, and various other panel to panel attaching points. The originally sealed joints are obvious and any damage to these sealed locations should be corrected by resealing. Attaching points of new replacement panels should be resealed. Replacement lids and doors will also require sealing in the hem flange areas.”

GM provides adhesive location within vehicle-specific repair procedures. Also, linked within the procedures, is the Metal Panel Bonding document. This document provides approved adhesives for metal bonding.

Baffle locations are found in vehicle-specific BRMs under: Body Repair ➤ Collision Repair ➤ Visual Identification ➤ Overview Baffle Positions. Baffle Specifications document is linked within this area, which gives instructions on installing the baffle on the replacement part.

Always follow OEM repair procedures for all repairs. Failure to follow corrosion protection guidelines can lead to the premature failure of a repair. Using the proper corrosion protection ensures a complete, safe, and quality repair.

For additional GM information, check out the following pages:
Chevrolet OEM Information
GMC OEM Information
Buick OEM Information
Cadillac OEM Information

Additional I-CAR Collision Repair News you may find helpful:

• Collision Information Website Access: General Motors
• Corrosion Protection Guidelines
• Step-By-Step: Accessing General Motors Repair Information

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Related I-CAR Courses

Course Corrosion Protection

Course General Motors (GM) Company Collision Repair Overview

Course Seam Sealer