I did not want to remove the wiring from the head light shell under the principle of letting sleeping dogs lie. Disturbing 40 year old wiring inside the shell seemed like asking for problems not to mention the fun of installing the wiring again. So, I removed the wiring harness from the frame and left it connected inside the headlight shell.
The headlight shell, although grungy, had original paint in very good condition. This bike had a Wind Jammer fairing from almost day one installed by the original owner. One advantage is it protects the head light shell from dings, bug guts and to some extent keeps it shaded so fading is minimized. Plus, for the last 35 years, the bike has always been garaged.
After I cleaned it up, other than some dings and scratches, the original finish shown through.
I decided that the nicks could be repaired in place and I posted a note to the Airhead BMW Club (ABC) for some advice on the best way to repair the paint.
NOTE: If you haven’t joined ABC, do it. The mail reflector is a great resource and font of wisdom and knowledge about Airhead BMWs. I’ve learned a great deal from folks who are very generous with their time and advice.
I got a detailed reply from Gale Gorman a man with a lot of paint experience. Here is his advice.
“That old finish is beautiful and I’m sure it was lacquer. Look for black lacquer touchup paint. I don’t know who sells it but a Google search might turn one up.
If that doesn’t do it, I can put a little black lacquer in a nail polish bottle and send it to you.
Clean spots with a good pre-paint cleaner. Eastwood sells PRE, DuPont sells Prep-Sol, and all the other players sell something. If you don’t have an automotive paint store nearby, NAPA keeps a small inventory of Martin-Senour products and Carquest usually has a little bit of DuPont. If you have acetone or lacquer thinner that will do it.
Once the spots are clean you can apply the first coat of black. No need to paint outside the lines. The paint will be thick as compared to ready to spray so allow it to dry probably an hour but if you’re in no hurry, several hours. Apply one or more coats until you think you have enough buildup to sand it smooth and not leave a crater. My goal would be to make the repair invisible. VERY CAREFULLY sand the repair with 600 grit until it gets close to flush and switch to 1000 grit. The finer grit merely removes the scratches left by the coarser.
Next step is rubbing compound and that may be too harsh. Try polishing compound first to see if the scratches disappear and a gloss starts to show up.
Final step is a cleaner type wax.
And that is approximately why paint and body shops seem to charge outrageous amounts.
This made sense as it’s a variation on the standard drill for repainting. But, I’d also seen some comments about using Testor or other model paint instead of touch up paint. So, I figured I would do a little experiment and see which was the better option.
I found Dupli-Color makes touch up paint that matches various shades of car paint. My local NAPA store has Dupli-Color, NGSF 100, ScratchFix 2in1 “Universal Black”, which was on the shelf. And the local Hobby Lobby has gloss back model paint. I also have some Dupli-Color Lacquer paint pre-mixed for spray painting.
I had already stripped the paint from the switch housings, so I could use them to see how well each paint bonded and how well the gloss matched the headlight shell.
The first to be eliminated was the pre-mixed Lacquer spray paint as it goes on way too thin. Here is the Dupli-Color on the left and Model paint on the right.
I let these test areas dry for 4 or 5 hours. Both seemed to match the amount of gloss in the headlight shell paint. I took 220 grit sand paper and sanded each to see which bonded best to the bare metal. The winner was the Dupli-Color touch up paint. It was as hard to remove as the original paint I sanded off the switch housings.
I sanded down the test painted areas and then cleaned up the housings with Lacquer thinner and then hand painted them and let dry for several hours. The housings looked like new.
The push buttons had faded to dull grey. I originally tried soaking them in Armor-All but they faded after a month. I received a note from a reader with a recommendation to use Forever Black. I tried that and it restored them to a nice black sheen. Then I used some “303 Aerospace Protectant” instead of Armor-All which was also recommended by the same person. These are going to look very nice when mounted on the powder coated controls.
Next up, working on the headlight shell. I applied the touch up paint using a small paint brush set for painting models that I picked up at Hobby Lobby. I let the paint dry for an hour or so before adding another layer.
I ended up with three coats on the deep scratches and only a single drop was needed on the small dings to fill them in. I let the paint dry over night before staring to sand out the touch up paint.
I started with a small piece of 600 grit wet paper dipping it into water with a drop or two of dish detergent and sanded out the touch up paint.
There is a slight bright outline of original paint around the touch up paint so it’s a little bit proud of the original paint. Then I used 1500 grit moving to 2000 and finally 2500 grit. Lightly passing my finger tips over the surface told me if the touch up is still proud of the surface. I find when I close my eyes my fingers are a bit more sensitive to any high spots. When I was done with the 2500 grit, I could not feel any high spots. There is still a slight shiny perimeter around the touch-up paint, but its not detectable to the touch. I did not want to burn through the original paint, so I stopped when I couldn’t feel any high spots.
You can see in the above picture I managed to burn through some of the original paint at the edge of the bezel. I put some touch up paint on it and very carefully smoothed it down staring with 1500 grit instead of 600 grit. Sharp edges and protruding transitions are easy to sand through so being light in your touch and even starting to sand them with finer grit than flat surfaces avoids burning through the paint.
I used my Griot’s 3 inch random orbital polisher and the #1 polish (coarse) to start to bring out the shine.
Here is what the repair looked like after polishing with the #1 polish. The reflections make the repair look like bare metal is showing, but it isn’t. It’s very hard to get good pictures of a glossy surface and avoiding a flash is essential to seeing some of the detail.
I worked my way down through the #2 and #3 polish (very fine). I polished the entire shell using the #3 polish to make the level of shine consistent and this is how the shell looks after the paint repair.
Last, I used Armor All on the sheath of the wiring harness and brought back much of the original sheen and shine. The head light and wiring harness are ready for installation in the powder coated frame.