Hi, guys. I have a Performance White colored 2004 Mercury Grand Marquis GS that I inherited from my father-in-law when he passed about 6 months ago. The car was garage kept and only has 22k miles on it since he was ill for quite some time and didn't drive it much. The car was in perfect condition except for some damage to the bumpers that occurred when it was parked (it's from Long Island where parking is at a premium). The plastic front and rear bumpers both had spider cracks and some small dings mostly on the corners where another car(s) bumper obviously ran up or under the Mercury's bumpers overflexing the facia and cracking the paint and plastic in multiple areas.
I wetsanded the spidered the affected areas with 400 grit which took it down through the primer and down to bare plastic in most places. I filled and sanded any dings or pockmarks with spot putty and primed anywhere there was exposed plastic or putty. By the time I was done it was obvious that there it would be easiest to paint both bumpers in their entirety than just the damaged areas.
Overall the car has a typical modern 2 part base/clear paint job. Unfortunately, since I was doing this on a budget, I couldn't afford to go that route. So my local paint jobber suggested a single stage paint system: BASF Limco 1 synthetic enamel with Limco LH130 reducer/hardener. Also, I don't have an automotive paint gun, so I used my Iwata airbrush with the largest needle, which is 0.5mm. The tech sheet suggested a 4:1 mix ratio, but that was for a typical auto paint gun. The jobber recommended using a 2:1 ratio, but after some experimenting with different air pressures and mixture ratios I found that 1:1 at 40 psi worked the best. So, although it took forever with the airbrush, I now have both bumpers painted. The paint provided by the jobber was a perfect match, and I'm glad I went to him instead of to an Autozone or Pep Boys.
The quality of the finish is not too bad considering the equipment used and the fact that I was doing this in the entrance to my garage. There is some orange peel and a few paint blobs that burped out of the airbrush if I sprayed for too long without running some thinner through it to clear it. Also, there were some little black knats that seemed to have an affinity for wet white paint. I found it did less damage to just paint over them than to try to pick them out.
Anyway, so here I am with both bumpers painted and no clue how to finish them. Do I wet sand or compound/polish or both? I have a Makita 9227C rotary buffer and an air powered DA sander/buffer with adjustable speed. I have a 3M Superbuff pad and 3M extra heavy duty rubbing compound that I use on my boat every year to remove the inevitable oxidation, but I'm sure that's too aggressive for the car. I also have some 3M Perfect-It II Finishing Material polish that I follow up the compounding with on the boat before I wax it every year.
So basically my question is: what do I have to do to the bumpers to remove and defect and finish them so they will shine like the rest of the car. I would appreciate if you could suggest any specific products I need to get or procedures I need to follow to get the best results. I have various wet/dry 3M sandpapers up to 2000 grit, but that might not be fine enough. Also, I probably need to buy some polishing pads for my DA or rotary. And I don't know what polish/glaze/whatever would be best to use with a specific pad.
Any advice you can provide would be kindly appreciated. Sincerely,
-Steve D
I wetsanded the spidered the affected areas with 400 grit which took it down through the primer and down to bare plastic in most places. I filled and sanded any dings or pockmarks with spot putty and primed anywhere there was exposed plastic or putty. By the time I was done it was obvious that there it would be easiest to paint both bumpers in their entirety than just the damaged areas.
Overall the car has a typical modern 2 part base/clear paint job. Unfortunately, since I was doing this on a budget, I couldn't afford to go that route. So my local paint jobber suggested a single stage paint system: BASF Limco 1 synthetic enamel with Limco LH130 reducer/hardener. Also, I don't have an automotive paint gun, so I used my Iwata airbrush with the largest needle, which is 0.5mm. The tech sheet suggested a 4:1 mix ratio, but that was for a typical auto paint gun. The jobber recommended using a 2:1 ratio, but after some experimenting with different air pressures and mixture ratios I found that 1:1 at 40 psi worked the best. So, although it took forever with the airbrush, I now have both bumpers painted. The paint provided by the jobber was a perfect match, and I'm glad I went to him instead of to an Autozone or Pep Boys.
The quality of the finish is not too bad considering the equipment used and the fact that I was doing this in the entrance to my garage. There is some orange peel and a few paint blobs that burped out of the airbrush if I sprayed for too long without running some thinner through it to clear it. Also, there were some little black knats that seemed to have an affinity for wet white paint. I found it did less damage to just paint over them than to try to pick them out.
Anyway, so here I am with both bumpers painted and no clue how to finish them. Do I wet sand or compound/polish or both? I have a Makita 9227C rotary buffer and an air powered DA sander/buffer with adjustable speed. I have a 3M Superbuff pad and 3M extra heavy duty rubbing compound that I use on my boat every year to remove the inevitable oxidation, but I'm sure that's too aggressive for the car. I also have some 3M Perfect-It II Finishing Material polish that I follow up the compounding with on the boat before I wax it every year.
So basically my question is: what do I have to do to the bumpers to remove and defect and finish them so they will shine like the rest of the car. I would appreciate if you could suggest any specific products I need to get or procedures I need to follow to get the best results. I have various wet/dry 3M sandpapers up to 2000 grit, but that might not be fine enough. Also, I probably need to buy some polishing pads for my DA or rotary. And I don't know what polish/glaze/whatever would be best to use with a specific pad.
Any advice you can provide would be kindly appreciated. Sincerely,
-Steve D
