Cracks in Hood Support

[Melmark93]

The kraken on mine...

Location - note, it is outboard of the rubber hood stop.

And you can see the material properties on the passenger side of the hood, along the edge.

The UP is for unsaturated polyester resin, reinforced with glass fiber (GF), mineral filler (M) and other additives.

Does everyone else have KR3V-16612-A? Or anyone have a B (or C, etc) as the suffix, which may indicate a revision?

My crack is in this same location, outboard of the stop and is a suffix A.

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[Snoopy49]

And you can see the material properties on the passenger side of the hood, along the edge.

The UP is for unsaturated polyester resin, reinforced with glass fiber (GF), mineral filler (M) and other additives.

Does everyone else have KR3V-16612-A? Or anyone have a B (or C, etc) as the suffix, which may indicate a revision?

My markings are the same as yours, @Houston Kid and Mel's. My car is a Feb 28th build.

 

[WD Pro]

I feel for you guys and although I don't have a dog in the fight, I do have a comment to make.

Trying not to do my usual trick of over thinking / over complicating things, I do wonder if temperature is a consideration ?

I believe the materials used in the hood are likely to become brittle when cold and that thin web in tension (from poorly adjusted hoods / dropping hoods to close etc) coupled with storage conditions / usage conditions / stresses whilst driving etc is obviously enough to cause the failure

I accept that Ford should have allowed for all those parameters and the design is obviously flawed i.e. in no way should it be used as an excuse etc. I really hope you guys get everything sorted out OK

WD

 

[Houston Kid]

My car was a November 23 build. Very late build date.

 

[Houston Kid]

Just got the phone call. Ford is replacing the hood.

 

[protraxduner]

I would assume at this point replacing the hood, with likely same defective hood, isn't solving anything. Unless someone has confirmed a change was made and there is a 'new' hood getting spit out now....

 

[Jmeo]

Maybe its just me, but I would rather have a two stage bonding epoxy applied to the crack, then a coat of touch up paint, then go the the bother of a new hood, especially having PPF already applied. The ONLY way to do it correctly is to paint the hood and blend the fenders, A posts, and possibly bumper cover. Not worth it to me for a minor crack that can be bonded, touched up and be mostly out of sight.

My car has what look like dings (very hard to see) on the passenger fender. They are a factory defect in the fender mold. I chose to not have it repaired for all the reasons I mentioned above.

Just my opinion, no offense to those who disagrees.

 

[Epiphany]

Just got the phone call. Ford is replacing the hood.

Can you share any of the correspondence?

 

[protraxduner]

I too would rather have small cracks, even not fixed than a repaint blend of the entire front end...NO thanks. Now if the crack causes issues or somehow this tranfers to the outside then that is a hole other problem. I mean it sucks but no good options on fix

 

[Snoopy49]

This is from the 2020 Mustang Service Manual.

Sheet-Molded Composite (SMC):

• Sheet-Molded Composite (SMC) is a type of thermosetting plastic that uses glass fibers or nylon fibers in combination with thermosetting polyester resins. When fully cured, Sheet-Molded Composite (SMC) is strong and rigid.
• Sheet-Molded Composite (SMC) is similar to, but not identical to fiberglass. Ford Motor Company uses Sheet-Molded Composite (SMC) in components such as fenders, hoods and liftgates.

Sheet-Molded Composite (SMC) Panel Repair

• Cover the break in the Sheet-Molded Composite (SMC) (front and back) with masking tape. This protects the damaged area from absorbing the prep cleaner and eliminates wicking of the cleaner through the fibers into the Sheet-Molded Composite (SMC).
• 
  
• Remove all waxes, silicones, dirt and road oils from the area surrounding both sides of the damaged area with a plastics wax and grease remover.
• 
  
• Remove the tape and sand the back of the repair area with an angle grinder, Dual Action (D/A) sander or by hand using 80-grit sandpaper. Remove all dust with a vacuum and tack cloth.
• Use Special Service Tool: ALCV-200.
• 
  
• Create a reinforcing patch using a piece of scrap Sheet-Molded Composite (SMC) that conforms well to the back of the damaged area or form a patch from fiberglass cloth.
• 
  
• Cut a section of cloth large enough to cover the repair, plus around the repair area. Cut a section of plastic film backing approximately larger than the cloth. Lay the plastic on a smooth, flat surface where it will be used to create a pyramid patch.
• 
  
• Follow manufacturer's directions and apply adhesive to the plastic film backing and smooth with plastic spreader to recommended thickness. Place the pre-cut fiberglass cloth on the adhesive-coated plastic film. Cover the cloth with a coat of repair adhesive and spread to the recommended thickness.
• Material: Plastic Bonding Adhesive / TA-9
• 
  
• Apply the prepared patch to the backside of the panel and compress. Follow manufacturer's instructions for adhesive cure. Remove plastic film after adhesive cures and sand as necessary to remove roughness.
• 
  
• Remove masking tape from the front side of damaged area and grind down to the backing patch. Use an angle grinder with a 30 to 40-grit wheel. Make a gradual taper in the area, this will prevent bull's-eyes or read-through in the finished repair. Sand prepared area with a Dual Action (D/A) sander or hand-sand with 80-grit sandpaper.
• Use Special Service Tool: ALCV-200.
• 
  
• Build a pyramid patch using fiberglass cloth or equivalent and adhesive. Following manufacturer's directions, apply patch to damaged area.
• Material: Plastic Bonding Adhesive / TA-9
• 
  
• Rough-grind area to remove excess adhesive. Sand repair area with 80-grit sandpaper, making sure to cut slightly below the Sheet-Molded Composite (SMC) finished surface. This will allow for a finish coat of plastic repair filler material.
• 
  
• Apply a finish coat of plastic repair filler material per manufacturer's directions.
• 
  
• Finish-sand, prime and topcoat using Ford-approved paint systems.

Sheet-Molded Composite (SMC) Panel Repair.pdf

 

[Tomster]

An epoxy doesn't replace the damaged glass gibers that were broken with the crack. The glass fibers are what give the composite hood reinforcement its strength. Once those fibers are damaged, then you loose the structural integrity.
The root of the problem needs to be discovered. I seriously don't think it is a defective design. There is a reason this is happening and I like some of the theories presented so far. My money is on incorrect installation or abuse somewhere in the assembly process. Maybe abuse isn't the correct word, but if some dumbest sat on the hood for a selfie or whatever, I could totally see this happening. The incorrect bumper adjustment could also be a cause. Dropping a heavy hood onto an incorrect bumper stop would cause undue stress. My observation is that if this was a design defect, more hoods would have these cracks.

As for new vs repair? I would take the new hood all day long. I would find the best shop to do the work and I wouldn't settle for a crap job. You don't have to use a dealerships body shop..... you have a choice.

 

[Tomster]

This is from the 2020 Mustang Service Manual.

Sheet-Molded Composite (SMC):

• Sheet-Molded Composite (SMC) is a type of thermosetting plastic that uses glass fibers or nylon fibers in combination with thermosetting polyester resins. When fully cured, Sheet-Molded Composite (SMC) is strong and rigid.
• Sheet-Molded Composite (SMC) is similar to, but not identical to fiberglass. Ford Motor Company uses Sheet-Molded Composite (SMC) in components such as fenders, hoods and liftgates.

Sheet-Molded Composite (SMC) Panel Repair

• Cover the break in the Sheet-Molded Composite (SMC) (front and back) with masking tape. This protects the damaged area from absorbing the prep cleaner and eliminates wicking of the cleaner through the fibers into the Sheet-Molded Composite (SMC).
• 
  
• Remove all waxes, silicones, dirt and road oils from the area surrounding both sides of the damaged area with a plastics wax and grease remover.
• 
  
• Remove the tape and sand the back of the repair area with an angle grinder, Dual Action (D/A) sander or by hand using 80-grit sandpaper. Remove all dust with a vacuum and tack cloth.
• Use Special Service Tool: ALCV-200.
• 
  
• Create a reinforcing patch using a piece of scrap Sheet-Molded Composite (SMC) that conforms well to the back of the damaged area or form a patch from fiberglass cloth.
• 
  
• Cut a section of cloth large enough to cover the repair, plus around the repair area. Cut a section of plastic film backing approximately larger than the cloth. Lay the plastic on a smooth, flat surface where it will be used to create a pyramid patch.
• 
  
• Follow manufacturer's directions and apply adhesive to the plastic film backing and smooth with plastic spreader to recommended thickness. Place the pre-cut fiberglass cloth on the adhesive-coated plastic film. Cover the cloth with a coat of repair adhesive and spread to the recommended thickness.
• Material: Plastic Bonding Adhesive / TA-9
• 
  
• Apply the prepared patch to the backside of the panel and compress. Follow manufacturer's instructions for adhesive cure. Remove plastic film after adhesive cures and sand as necessary to remove roughness.
• 
  
• Remove masking tape from the front side of damaged area and grind down to the backing patch. Use an angle grinder with a 30 to 40-grit wheel. Make a gradual taper in the area, this will prevent bull's-eyes or read-through in the finished repair. Sand prepared area with a Dual Action (D/A) sander or hand-sand with 80-grit sandpaper.
• Use Special Service Tool: ALCV-200.
• 
  
• Build a pyramid patch using fiberglass cloth or equivalent and adhesive. Following manufacturer's directions, apply patch to damaged area.
• Material: Plastic Bonding Adhesive / TA-9
• 
  
• Rough-grind area to remove excess adhesive. Sand repair area with 80-grit sandpaper, making sure to cut slightly below the Sheet-Molded Composite (SMC) finished surface. This will allow for a finish coat of plastic repair filler material.
• 
  
• Apply a finish coat of plastic repair filler material per manufacturer's directions.
• 
  
• Finish-sand, prime and topcoat using Ford-approved paint systems.

Sheet-Molded Composite (SMC) Panel Repair.pdf

I used to work with fiberglass. Repairing cracks like that would never be as strong as original. If you cant bear to replace the hood, then its worth a try, but the root of the problem has to be discovered or it most certainly will happen again because the repair isn't as strong as the original structure.

 

[Houston Kid]

Can you share any of the correspondence?

I don't have any to share at this point. The warranty rep called and said Ford is replacing the hood is all I have.
My concern is will it happed again if it is a design flaw and not a fitment issue. I did not PPF the car and my white is about as easy to color match as it comes.
If it does happen again, by then hopefully Ford will have a fix because I imagine Ford is about to get a dozen or more requests for new hoods.
I also think there is about to be a shortage of hoods. The rep said she ordered the hood so for now that is promising.

 

[Epiphany]

The warranty 'rep' that called...was this from the dealer, your region....?

 

[kilobravo]

I have to admit HK, I'm surprised that Ford is replacing it. So, who is going to paint and who is going to stripe it?

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