Not Knowing What You Don't Know About Collision Repair

A good friend of ours, Mark Olson from VeriFacts, always says, "You don't know what you don't know." If you really think about that statement, you will realize how true it is. We hope you read our last article, "The Cost of Training and Why Some Shops Still Pay for It." We will continue to try and convince you that training should be an essential part of your business plan by giving you some insight into how Mark's statement applies to collision repair. In this article, we are going to break down the collision repair shop into departments and dispel the more common myths.

Estimating Department

Myth: Plastic radiator core supports are not structural. FALSE. Composite radiator core supports are a structural component. The substrate or attachment method used does not make a difference; a radiator core support is structural. Composite or hybrid design (composite and steel) core supports are utilized by many manufacturers for many reasons, such as:

• To lighten the overall weight of the vehicle for fuel economy.
• To lessen the transfer of collision energy from the applied forces to limit the damage sustained to the upper and lower uni-rails.
• To allow more design options and features.

Additionally, most ductile fractures on composite radiator supports cannot be repaired due to the orientation and calibration of the satellite airbag crash sensor, generally affixed to the component.

Myth: Measuring of the vehicle is not necessary for estimating. FALSE. Any collision-damaged vehicle must be measured to ensure the applied forces did not penetrate through the vehicle and cause collateral damage to other components. Almost every vehicle produced in the last five years contains Advanced High Strength Steels (AHSS) in the rear area of the front lower uni-rails and passenger compartment reinforcements (Boron alloyed steel, Martensite, Dual Phase, etc.). The AHSS are designed to "hold open" and transfer collision energy around the passenger compartment. Even in a minor collision event, many times the rear suspension components will flex and become deformed. Even severely damaged vehicles must be "Pre-Measured" because the only way to truly know the extent of the damage is to measure the vehicle, and the most advantageous time is during the blueprinting (estimating) of the vehicle. The process you use for measuring can vary based on the stage in your process.

Some methods to consider include:

• Visual inspection. Testing the opening and closing effort of the closure panels and looking for abnormal movement and/or operation.
• Your fingers, by placing your fingers between the rear edge of the rocker panel and the rear tire on one side of the vehicle and comparing it to the other side to see if there has been movement.
• A tape measure or a tram gauge. Obtaining the vehicle dimensions from the OEM, ALLDATA Collision, MOTOR or Mitchell, you can take measurements on the vehicle to compare them to the specifications to determine the extent of collateral damage.
• An electronic, three-dimensional measuring system. The best way to determine the structural misalignment is to put the damaged vehicle on a two-post lift and measure the vehicle. Systems like Car-O-Liner Vision x3 and Chief are set up to allow diagnostic measuring on a two-post lift with a three dimensional printout.

Structural Department

Myth: I can "tie" the vehicle down using hooks attached directly to the formed holes in the underbody of the vehicle. FALSE. Although the AHSS found in today's vehicles are three to five times stronger than the materials used a few years ago, AHSS is one-and-a-half to two times thinner. By attaching a hook into a formed hole in an AHSS component on the underbody of the vehicle to secure the vehicle to the structural realignment apparatus (frame machine), you can cause ductile fractures to that area once force is applied by the hydraulic ram (pulling tower). You have now caused collateral structural damage, and the damaged component will most likely require replacement.

Myth: If I heat the component to "cherry red," the component will soften and I can fix it. FALSE. Since the introduction of the mass-produced GM X Type monocoque body construction (Chevrolet Citation), manufacturers have created rules for heating times for steels. No manufacturer has ever recommended heating a panel to a cherry red color (approximately 1,700 degrees F), which is too hot and starts to temper the steel. This changes the metallurgical properties (tensile and yield strength). Basically, you have made the component stronger but more brittle, and the component may not react the same way in a subsequent collision event.

Heating rules from the manufacturers are generally for Mild Steel (MS) or low grade High Strength Steel (HSS); the recommendations generally call for heating to a dull red (700 to 900 degrees F) for 90 seconds in two applications cumulative (three minutes in two applications, forever). But almost every manufacturer (except Ford and GM on some select Full Frames) prohibits the use of heat due to the AHSS found in today's vehicles.

Myth: Aluminum structural components can be structurally realigned. FALSE. Most aluminum intensive vehicles, such as the Audi A8, A8L, R8 and S8, 2004-2008 BMW 5 and 6 series (front Graf components), Ferraris, Lamborghinis, Mercedes Benz (SLS Class), Porsche Panamera, Carrera GT2 and GT3 and McLaren/Mercedes Benz SLR prohibit any structural realignment, while Jaguar XK and XJ and the Audi TT allow only some structural realignment to specific structural components. Attempting to structurally realign an aluminum-intensive vehicle will cause micro-fractures to form in the component that cannot be seen with the naked eye. These can affect the reaction of the component(s) in a subsequent collision event or even during normal driving operations.

Metal Department

Myth: Drilling holes and slap-hammering deformities in outer body panels is a proper procedure. FALSE. Drilling holes into outer body panels will cause the panel to become weaker and create corrosion hot spots. Deformities to outer body panels should be repaired using hammer and dolly techniques in areas where the backside of the panel is accessible; in areas where the backside is inaccessible, weld-on dent removal pins are acceptable. Additionally, the proper corrosion resistant primers and rustproofing products must be applied after repairs are completed.

Myth: Undercoating is a corrosion protection product. FALSE. Rubberized undercoating is not considered corrosion protection; it is considered a corrosion resistant product. Corrosion can be defined as the degradation of a material due to a reaction with its environment. Many structural alloys corrode merely from exposure to the moisture in the air (electrolytes), but the process can be strongly affected by exposure to certain substances, such as dirt, road salt and chemicals. Corrosion can be concentrated locally to form a pit or crack, or it can extend across a wide area, more or less uniformly corroding the surface. These pits or cracks can cause a degradation of the area.

Degradation implies deterioration of the physical properties of the material. Corrosion hot spots are formed by the collision event itself through the crushing of the metal (causing the paint material to loosen and detach from the substrate), from unprotected dissimilar metals contacting each other (galvanic; steel and aluminum), from the collision repair process itself through the hammering and welding to the components and finally from lack of application of the proper products to protect the repaired or replaced areas. Corrosion protection can simply be described as something that cures or dries. Products that are used to protect bare metal would be acid or self etch primers, followed by a coating of epoxy primer. In the collision repair industry, the acid etch primer replaces the zinc coating or galvanizing on the steel that is applied at the steel mill and the zinc-phosphate coating applied at the factory to the vehicle. The epoxy primer replaces the electrodeposition primer or "e-coat" applied to the steel components at the factory. In the collision repair field, after the application of the acid and epoxy primers, collision repair technicians then apply primer surfacer, sealer primer and then the top coats (color coat and clear coat) to the outer panels and the accessible backside areas of the inner panels. In inaccessible areas, rustproofing products are applied. Rustproofing products can simply be described as something that does not fully cure. In the collision repair field, technicians would use a wax or petroleum-based product that has a creeping capability (can creep into crevices). Rustproofing is necessary because collision repair facilities cannot "dip" the vehicle into a vat or bath pool and electrostatically apply the corrosion resistant and rustproofing products. On the underside of the vehicle (underbody) and in wheelwell recesses, some manufacturers apply undercoating on top of topcoats, but most manufacturers are going to a urethane type of sprayable seam sealer that is either black in color or requires a black paint to be applied after application. The one problem with undercoating is that, when applied to the underbody of the vehicle, road debris (stones, rocks, nuts, bolts, twigs, etc.) impact the underbody. Just from the use of the vehicle, the torsional movement (twisting) of the components will cause small ductile fractures (chips) in the undercoating. These chips allow moisture to creep into the area and then seep between the undercoating and the underbody, allowing corrosion to form quickly. Most German OEMs (Mercedes Benz, BMW, Audi, VW and Porsche) prohibit the use of undercoating on their vehicles.

Myth: MAG (Metal Active Gas), MIG (Metal Inert Gas) or GMAW (Gas Metal Arc Welding) is the proper procedure to install a welded-on component. TRUE and FALSE. Depending on the OEM's repair procedure, this could be true or false. Most OEMs allow MAG/MIG/GMAW for installation of welded-on panels, either as part of the procedure, as an option when Squeeze Type Resistance Spot Welding (STRWS/RSW) is not available, or both sides of the panel flanges are inaccessible. RSW is the accepted procedure by most OEMs, some OEMs only allow RSW and other select OEMs only allow rivet-bonding (structural rivets and structural bonding adhesive) to attach the panels and MAG/MIG/GMAW on the common butt joints (generally open butt joints). Mercedes Benz and BMW are two OEMs that require rivet bonding to replace OEM RSW and prohibit the use of plug welds to replace OEM RSW.

Hopefully, this article has brought to your attention the importance of obtaining the proper and correct OEM repair procedure from the OEM website, ALLDATA Collision or other source to ensure that the consumer's vehicle is repaired properly and your liability exposure is protected.

Feel free to contact us at any time if you have any questions.