The title of the previous post Light at the End of the Tunnel? was prescient. Yup, the light was an oncoming train.
Polishing the paint left a lot of pig tails – small loops gouged in the paint. I kept hoping that the finer grades of polish would remove them, but no luck.
I also managed to sand through the clear coat in a couple of areas. Not good!
And while polishing with the smallest 2″ DA sander I managed to rub the edge of the backing plate against the an adjacent surface leaving long gouges in the paint.
OK, taking them in reverse order:
I carefully sanded the backing plate gouges starting with 1500 grit sandpaper. With luck, patience, and good technique I might – just maybe – be able to sand out the gouges without sanding through the clear coat. After 15 minutes of careful and paranoid work the gouges were gone and the clear coat was still intact. Great relief!
Next I got a quart of clear coat and a can of clear coat blending agent. After masking off a large area around the damaged places I sprayed three coats of clear coat. Started with a quick spray over the damaged area and then sprayed and blended progressively larger areas for the next two coats. After letting it dry over night I carefully sanded it, starting with 2000 grit sandpaper, and polished the areas. The results weren’t perfect – there is a slight banding where the original clear coat was feathered into the base coat. But it is hard to spot. I asked a friend to try to spot the repaired areas and he couldn’t find them. I know where they are, but it is something I can live with.
The pig tails were a major problem. I think I finally identified the source: I think it was a combination of less than perfect cleaning of the surface which left small pieces of paint from the previous sanding stage combined with using a hard foam pad with a smooth surface. Specifically, a Chemical Guys Hex-Logic Orange Medium Heavy Cutting Pad. Other pads have a more open foam surface which I believe can absorb paint particles rather than trapping them between the pad and the paint surface.
The pig tails were deep enough that I couldn’t polish them out. I also couldn’t sand them out with 3000 grit sand paper. The only thing that worked was to go all the way back to 1500 grit sand paper and sand the whole surface. Carefully – very carefully! The clear coat is getting thin, so I’m at constant risk of sanding through it. The 1500 grit was followed by 2000 grit and 3000 grit – and then 5000 grit. Yup, I added another grade of sandpaper. The goal is to get the surface as smooth as possible before polishing.
When I start polishing again I’m going to be using softer open cell foam pads. Specifically, I will be starting with a yellow Griot’s Garage Boss Perfecting Pad. This pad is rated for removing light defects – we will see how it works after the 5000 grit sandpaper.
I also got a rotary buffer with some softer pads and will see how it does for polishing.
In summary, I’m now entering the third month of a 1-2 week job. Yeah, about par for the course…
On a better note, we spent last week in Pennsylvania visiting relatives and exchanging bumpers at Librandi Plating. In I’ll Be Chrome For Christmas I covered how I ended up with the wrong rear bumper. This time I unwrapped the bumper before loading it up! Yes, this time it was the correct bumper. Librandi offered to plate another part to make up for the inconvenience, so I took the cowl covers that go at the base of the windshield. I had wanted these done originally, but they pushed me over budget and came back home with me. I’m looking forward to getting them back!