Wednesday, March 26, 2014

Dent Repair & Metal Finishing on Right Rear Quarter

A month has passed since my last update, but activity has been steady and productive as the adventure begins on straightening the right rear quarter panel in preparation for filler and primer.  And with the exception of another week of international travel for work as an interruption, I have been working on the car pretty steady for the remainder of time.

In contrast to the left rear quarter, the right rear quarter had seen significantly more abuse over its lifetime.  In fact, some of the metal repairs that would be required were actually to reverse the effects of botched metal work that had been done in excess of thirty years ago and I was actually able to identify a shopping cart impact that left the front of the quarter clearly indented with perfectly symmetrical vertical divots from front to back.  Further to that, I had a deep crease in the lower front apron area and quite a bit of damage to the leading edge of the “hip” area at the front top of the panel.  Plenty of work to be sure!
First things first, however.  A huge benefit of the right quarter was that the spots of surface rust were far fewer than on the left.  This made scrubbing them away with a surface prep disc on my angle grinder a relatively quick affair.  As expected, there were several tiny areas where some micro-pitting was evident and I marked each of these areas for later attention from the Speed Blaster.

Once the surface rust was gone, I went over the entire panel from front to back with a clean 36-grit disc on my DA sander to clean up and prep the panel for a swab with diluted Prep & Etch to preserve the bare metal as the work progressed.  Then, I set about tackling the top section of the quarter where earlier work had been done (and quite poorly I might add) as this area would present some unique challenges to getting the metal straightened.
To begin, I used my giant Sharpie marker to stain the repair area so I could block over the surface to identify and clearly highlight the damaged area details.  This actually revealed a much more extensive and complicated repair area than I had estimated, but the details were clear and the path set to get going on the repairs.

Starting with my bulls eye pick, I slowly started raising the low areas along the roughly 20-inch gouge in the panel as well as the palm-sized dent in the “hip” and a significant ripple along the forward character line.  This is a very iterative and slow, painstaking process that rewards patience and gentle persuasion.  Slowly, the metal started to gradually move back into place and after several cycles of staining and bumping, I reached a point where I would need to use my stud welder/puller to remove the deeper section of the crease.  After several hours this process, the areas was returned to within 98-99% of its original shape and I could move on to the next repair areas, until all of the metal work was complete.
The next step was to return to the slightly pitted areas I had earlier marked so I could ensure every trace of rust was removed by using the spot blasting nozzle on my Speed Blaster tool.  This nifty tool allows me to very quickly and cleanly spot blast each small spot of pitting, leaving rust-free, clean metal behind.  This few minutes spent ensured I would not have issues with future re-development of rust in these areas and contributed to considerable peace of mind as well.

With the spot blasting work complete, I once again sanded the entire panel with 36 grit paper to establish a clean surface with sufficient “tooth” to allow the “heavy” All-Metal filler to be applied to seal the welded areas, and to allow the formal body work to begin.  By the time you read this, that work will be well underway!  Stay tuned!
Surface prep discs were used to scrub away the bulk of the surface rust spots on the quarter.  Far less work involved here than on the left quarter for sure!

The upper "hip" area of the quarter had the remnants of a poor attempt to push out a heavy crease that ended up with surface rust in it from end to end.  The lighter gray area above and below the long strip where I scrubbed the crease shows the huge shallow dip along almost the entire front section of the hip.  This is going to require hours of metal finishing to get back in shape.

This lower apron area also had a major crease along it's full length that ended in a nasty cleft in the leading edge of the flare.

After all of the surface rust areas were scrubbed clean, I went over the entire quarter with my DA and 36 grit paper to smooth up and clean the surface to bare metal and to provide the ever important "tooth" to the metal required for proper filler adhesion.

Fortunately, only a little metal work was required on the top of the fender to get it into fine shape.

Using my trusty big Sharpie marker, I marked the entire damaged area of the hip so I could start sizing up the extent of the metal work that would be required to get this previously repaired area back into shape.

A few light passes with the sanding block and the damage was revealed.  Essentially, the entire area was one huge low spot with more heavy damage concentrated along the middle of the crease and lower on the front hip area.  These more heavily damaged areas are easily seen in this shot as they are the spots still colored in black marker.

After a few short minutes of work, the metal is starting to gradually move back into place.  However, there are many hours left to get this area corrected.

In this shot, most of the front hip area has been bumped back into shape with only small detail work left.  Notice how little black marker ink is showing in this area.  It is quite obvious I am working from front to back in this particular area.

The front hip metal work from a slightly different angle. 

As I moved back into the heavy crease, it became obvious I would need to gently pull this damage with my stud puller in order to get the metal to move enough to bring it up to the proper level.

After about 6-8 hours of gentle metal persuasion, the upper fender is pretty darn good.  It will need a very thin skim of filler to get it perfected, but that is pretty straight nonetheless.  Also, I have worked out the lower apron crease and a few other smaller flaws I found along the way.

For an extra measure of insurance, I chose to run over each former surface rust location with the spot blaster to make absolutely sure there would be no rust remaining in the metal pores.

Looks like the quarter panel came down with a case of the measles after spot blasting.  In this case, it is a very good thing!
 
 
Cleaned up with another pass of 36 grit paper on the DA and the quarter is looking much better than it did when I started!

After sanding, you can just make out the shadow of the heavy crease that once occupied this area of the upper quarter panel.

Rear of the quarter after metal finishing looks quite good.
 
And there it is!  The right quarter is ready to begin the slow process of filling and blocking on the way to a sealing coat of epoxy primer.