Many modern vehicles have color-keyed mirror housings that are black and the body color. In scale, it can be a challenge to get a clean line between the two colors. Here’s an easy way to deal with that particular challenge.
The goal is to make the mirror housings look uniform on both sides and create or define lines between the colors for masking and painting. I’m using a Tamiya 1/24 scale Honda NSX to demonstrate the process.
A delicate mold line runs along the top of the mirror housing where one of the paint lines should be. Using a sharp blade, lightly trace the section of the mold line that matches the paint line location at least a dozen times to make a path for scribing.
Then, using the back side of the blade, scribe the line in; again using light passes until it is the desired depth. For consistency, do the same section on each mirror before moving on to the next line.
For this part, scribe the leading edge under the “spear” detail. Start with the sharp side of the blade to make a good path before flipping the blade and completing the final scribing.
To scribe the upper part of the same spear(s), cut masking tape to use as a flexible straightedge. This line goes all the way across the pylon to where the mirror mounts to the car. Make the first few passes lightly to avoid moving or cutting through the tape.
The next line is the top inboard one. Again, employ tape as a guide on difficult or long lines like this one. I darkened the lines I scribed on the right side mirror with black Tamiya Panel Line Accent Color (No. 87131) for clarity.
Scribe the bottom of the pylon last, making it an extension of the spear-tip shape. Tape helps to create a nice, straight line.
Flow Panel Line Accent Color into the lines you’ve scribed to check uniformity and depth. Assess them and fine-tune the scribing if necessary. Remove any burrs by wet-sanding with 1000-grit sandpaper and scrubbing lightly with a toothbrush.
Airbrush the mirror housing the same color as the body of your car. In this case, I used Tamiya Pearl Blue (No. LP-47).
Allow the body color to completely dry (a couple of days should do it). Then hand-paint the housings gloss or semi-gloss black, depending on your vehicle. It takes less time to brush-paint them than to mask just one of them at this point.
Install the reflective mirror faces into the housings. After trimming them from the sprue, the mirrors are ready to be mounted to the car.