Proper sectioning techniques are changing dramatically

Jan. 1, 2020
Sectioning locations that were common for 20 years often are no longer available on today's vehicles.

How many times have you heard "I have been doing this for 20 years so I know that vehicle maker X always has a sectioning location here?"

That statement may have been true at one time, but if a repair procedure was on a previous generation vehicle, it doesn't mean that the same repair procedure is on the current generation vehicle. Sectioning locations that were common 20 years ago often are not available any longer.

When replacing the B-pillar reinforcement on the 2013 Honda Accord, MIG brazing is used in locations that can't be reached with spot welder arms. (IMAGES / I-CAR)

In some cases the recommended attachment method or weld joint configuration may also have changed. Keeping up with evolving technologies and changes can puzzle even the most experienced technician.

There have been many changes in how vehicles are being built; therefore, vehicle repairs also must change. For example, panel thicknesses may be getting thicker or thinner, depending on the purpose. The use of ultra-high-strength steel (UHSS), aluminum, magnesium and carbon fiber in vehicles is increasing everyday. The collision industry is in the midst of changes that alter how we think about repairs. Let's review some examples to highlight some of these changes.

When welding the sectioning joints on the 2013 Ford Taurus front inner lower rail the weld is made from the inside.

In some cases, it may only be a seemingly slight change, however, it can be the difference between doing a repair correctly or incorrectly. As you read this article you may think that some of these changes are not critical. Before you make an opinion about that, ask yourself this: "Do I want to re-engineer a vehicle today?"

That is exactly what you would be attempting to do if you chose to ignore a repair procedure. A common statement that can be heard in repair facilities across the country includes, "This is the way I've always done it." Let's examine some of the repair procedures that show why this statement is no longer a safe assumption and can comprise a safe vehicle repair.

The sectioning joint for the front lower rail on the 2012 Malibu is located at the die marks shown here.

Changing repair procedures

Let's take a look at some of the updates the vehicle makers have made to their repair procedures. Take the 2013 Ford Taurus for example. The front lower rail is made of two rail halves and has three sectioning locations for the lower rail. This is not surprising; however, in the Ford body repair manual (BRM) it says that the "Member assembly - front side outer (outer lower rail) is made of 350 MPa steel and the Member assembly - front side inner (inner lower rail) is 600 MPa steel." Is that going to change how you think about repairing that vehicle? It should, but let's look further into the repair procedure.

In the Ford BRM it also shows an offset repair joint, which is not uncommon but here is something you may have not seen. When welding the inner lower rail the Ford BRM says, "Seam weld along the inside of the sectioning joint using a MIG welder and ER70S-3 wire 0.9 mm (0.035 in) to 0.11 mm (0.045 in) diameter."

This is a vehicle maker repair procedure that differs from what was done 20 years ago. Without looking at the collision repair information you may have not been aware of this update. In this example, not only has the weld joint changed but also the side of the joint you actually weld. In this case, the root gap and weld penetration will be critical in completing a complete and safe repair.

Another example includes the front compartment side rail sectioning (front lower rail sectioning) on the 2012 Chevrolet Malibu. The front lower rail sectioning procedure is fairly straightforward. Chevrolet has placed a die mark on the front lower rail tip to indicate the cut line for the damaged part and the service part.

You may think that there is another sectioning joint either before or after the strut tower. If you made this assumption, you would be wrong. Instead of a sectioning joint, Chevrolet has a procedure to separate the Front Compartment Front Half Rail Replacement (front lower rail) at a "mid joint" that reads as follows:

  • "(Step) 7. Locate and drill the factory welds along the flanges of the rail, only up to and including the rail mid joint just forward of the dash panel.
  • "(Step) 8. Drill out the factory welds.
  • "(Step) 9. Pry open the outer layer of the rail at the front rail mid joint to allow the front portion of the rail to be removed from the vehicle.
  • "(Step) 10. Remove the damaged front lower rail.
  • "(Step) 11. Drill out the factory welds at the service rail assembly mid joint.
  • "(Step) 12. Remove the forward portion of the front rail assembly at the mid joint."

So instead of having a sectioning location, Chevrolet has created a partial replacement procedure. If the damage is not repairable and extends beyond the mid joint the only other option is to replace the entire front lower rail. So here again, a vehicle maker is making changes to repair procedures that the collision repair industry has been doing for years.

Now lets take a look at the 2013 Honda Accord. This is an all-new vehicle for 2013 and it has some interesting features in the passenger compartment reinforcements. The Honda BRM states, "4-door: The front inner upper pillar, the center pillar upper stiffener, the side sill stiffener, and the inside sill reinforcement are made from 1500 MPa steel."

Basically, this means that some of the reinforcements on the side of the vehicle are about six times stronger than mild steel. In the past the only place we would see steel that was anywhere near 1500 MPa would have been in bumper reinforcements or door intrusion beams. You probably have already thought that with a steel of this strength is damaged, all you would have to do is cut off the damaged parts and replace them. In this case, you would be correct in that assumption.

But you may be wondering, "How am I supposed to attach these parts?" Honda's BRM continues to say that, "For this reason ... the 1500 MPa parts should NEVER be repaired, and NEVER be welded by MAG (GMA MIG) welding; they must be replaced by only spot welding and MIG brazing if they are damaged."

You may be saying, "What did that just say?" or "Did I read that right?"

In this case GMA (MIG) welding has been the industry standard, however, it is now specifically warned against as a method on these UHSS parts. So when attaching these parts to the vehicle, the vehicle maker wants the parts spot-welded. Anywhere you can't reach with the spot welder arms, the vehicle maker is recommending MIG brazing.

As you have seen throughout this article, many things have changed from 20 years ago. Some changes have been small and some have been fairly drastic. The previous examples that have been presented provide proof that changes are occurring everyday.

Due to the multitude of changes it is very important for collision repair professionals to look at the vehicle maker's repair procedures before starting any repairs. This is also a reason that makes ongoing training even more important and essential to do a complete and safe repair.

I-CAR is dedicated to educating and informing the collision repair industry about these changes. One of the ways I-CAR is educating the collision repair industry about these changes includes an update to the I-CAR Structural Parts Steel Qualification Test (SPS05). Launching mid-year, the course will illustrate some of these changes in sectioning procedures and techniques.