DennisB - Summary: Paint bubbling on Ford Mustang’s is a common issue. At first glance the bubbled or blistered area looks like rust bubbling the paint, but wait this hood is aluminum!

Click on the image to the left too see a larger view. Aluminum cannot rust, but it can corrode. Corrosion under the factory paint causing paint to bubble is a very common issue. There’s even a TSB (Technical Service Bulletin) about this. The Ford Mustang is not the only vehicle affected either. The TSB includes Ford Explorer, Taurus, Expedition, Lincoln Navigator, Mercury Sable and more. Outside the 3 year 36,000 mile warranty, Ford owners are left to pay for this repair themselves. It does make Ford owner’s question their loyalty to Ford on their next new car purchase though.

Below is what the TSB # 06-25-15 has to say regarding the cause and the way to prevent this from happening again when the panel is repainted.

FORD:
2000-2007 Crown Victoria, Taurus
2005-2006 Ford GT
2005-2007 Mustang
2000-2003 Ranger
2000-2007 Expedition
2002-2007 Explorer
2004-2007 F-150
2007 Explorer Sport TracLINCOLN:
2000-2006 Lincoln LS
2000-2007 Town Car, Navigator

MERCURY:
2000-2007 Grand Marquis, Sable

This article supersedes TSB 04-25-1 to update the vehicle model years. ISSUE:

Some vehicles may exhibit a bubbling or blistering under the paint on aluminum body parts. This is due to iron contamination of the aluminum panel.
ACTION:

This TSB provides service tips and procedures, outlining methods to properly prepare and protect aluminum body parts from cross contamination.
BACKGROUND

Ford’s Scientific Research Laboratory has performed a number of tests on vehicle body parts returned for corrosion related concerns. Testing has revealed that the aluminum corrosion was caused by iron particles working their way into the aluminum body part, prior to it being painted. SERVICE TIPS AND PROCEDURE

When repairing a vehicle for corrosion or collision damage, it is essential that extreme care be taken to cover and protect all aluminum parts to prevent cross metal contamination. Areas in a shop where metal work is performed should be sectioned off, using at the very least curtain walls, to prevent metal dust migration. Cross contamination can also occur through the use of metal working tools (hammers, dolly’s, picks, grinding wheels, etc.). Tools used for aluminum repairs should be kept separate, and not used to repair other metals. Wire brushes used on aluminum should be made of stainless steel.
NOTE:THIS PROCEDURE SHOULD ONLY BE USED ON NON-PERFORATED METAL. REVIEW WARRANTY AND POLICY MANUAL FOR VEHICLE WITH PERFORATED METAL.

NOTE:READ THIS PROCEDURE COMPLETELY BEFORE PERFORMING ANY SERVICE.

  1. Corrosion should be removed by blasting. Use an aggressive blasting material, such as acrylic (salt grain size).
  2. Use a DA sander with 180 grit paper backed abrasive. Only sand and featheredge the damaged area.
  3. Mix and apply Ford approved epoxy primer, per the manufacturer’s label instructions. Bake at 140° F (60° C), or use an infra-red lamp for curing.
  4. If necessary, mix and apply two-part polyester filler to a slight over crown. Allow polyester filler to cure 20-30 minutes, or mix and apply spray polyester filler two-three (2-3) coats as necessary. Allow to cure per manufacturer’s label instructions.
  5. Hand-sand the repair area with 80 grit sand paper to remove excess filler.
  6. Finish-sand the repair area with 400 grit sand paper.
  7. Mix and apply Ford approved primer/surfacer per manufacturer’s label instructions. Bake at 140° F (60° C) or use infra-red lamp for curing.
  8. Sand the primer/surfacer with 400-600 grit to level the surface.
  9. The next two steps are wet-on-wet. Mix and apply to hiding Ford recommended basecoat material per manufacturer’s label instructions. Allow to flash.
  10. Mix and apply two (2) coats (2 mils minimum) of Ford approved clearcoat per manufacturer’s label instructions. Allow flash time. Finish bake at 140° F (60° C).