I tend to do any paintwork in the shed these days as I've found that if I try spraying paint in the garage, the overspray seems to get in the air and go everywhere.
I've been doing all the painting in the garage, trying my best to minimize overspray. But, this has limited my work time the past week since the fumes cause me to evacuate the garage for some number of hours after each painting session.
When I want to do a proper job in the future, I'll build a pop-up paint booth next to the garage from PVC pipe and plastic sheets, use an actual paint gun, and do the work on a wind-free day.
Unlike what I wrote in my previous post, I only used 800 grit paper on the primer. The goal is to have a final gloss paint surface that is shiny and free from orange peel and there's no need to have the primer base extraordinarily smooth to accomplish that. The 800 grit left the surface quite smooth so I decided to skip the 1000.
Directions on the can say the gloss black paint dries to the touch in 15 minutes and subsequent coats should be applied within 1 hour or after 48 hours. So, I made repeated trips out to the garage every 10–15 minutes to apply a total of five coats. The next photograph was taken while the paint was still wet after two coats.
As the reflection of the overhead lights shows, there is no sign of residual distortion from my repair, so all the work with Bondo, glazing putty, and the form tool paid off. Addendum: I realized after posting this that I hadn't positioned the reflection over the worst of the damage when I took the photograph so you'll just have to take my word for the fact that "moving" the reflection all around the mudguard didn't reveal any distortion.
As a reminder, the next photograph shows what the pre-Bondo mudguard looked like.
The paint can doesn't indicate how long it takes for the gloss black to "fully" dry. However, the "dries to the touch" time of 15 minutes, and the repaint time of less than an hour or more than 48 hours, is at 70 ℉. I've had the garage at 80 ℉ during the day in the current heatwave, rising to 87 ℉ overnight (the default setting I use for the AC in the summer, to keep sensitive items from getting too hot). Since the paint fumes are pretty unpleasant (not to mention, unhealthy), as soon as I finished the last coat I turned the AC up to 87 since I won't work in the garage again today.
Based on the rule of thumb that chemical reaction times reduce by half for every increase of 10 ℃, one day drying time will be equivalent to two days at 70 ℉. I'll finish the mechanical work (assembling the primary side, timing the magneto, attaching the fuel tank and oil line, etc.) before doing the color sanding of the mudguard, so it will have had the equivalent of at least five 70 ℉ days to dry before I sand it.
I couldn't be more pleased with how the mudguard looks at this point, so it remains for me not to screw it up when I do the color sanding and buffing. Unfortunately, this means I'll now how to polish and wax the front mudguard and fuel tank to keep them from looking out of place.