Third Option
Here’s a third possible option: Prime/Seal, Fly, Paint
1. Prep aluminum and fiberglass surfaces (Fill, Clean, Etch and/or Roughen, Clean Again).
2. Prime with a good 2-part epoxy primer: PPG DP48 system (or equivalent) plus reducer.
3. Immediately Seal Primer with House of Kolor SG-100 Intercoat Clear (or equivalent). Prevents oil, fuel, etc. from penetrating into the primer surface.
4. Assemble, Fly, and then Mod or Fix as required. Then, when you’re ready to “commit” to your final paint job . . .
5. Thoroughly Clean Surface.
6. Buff with 800 grit or higher (roughen the intercoat).
7. Paint.
Pros:
Easy to mod or fix the aircraft’s surface during or after the flight test period, but before final painting. (For various mods and fixes, just clean, re-prime, and seal the area with SG-100)
Do-it-yourself prep, prime, and seal process removes most of the labor costs from the painting process. Also, priming and sealing is easier than the final painting process which requires more skill/experience.
Looks better than just bare aluminum with primed fiberglass surfaces. In fact, the result looks great!
To paint, just clean, rough-up, mask, and shoot. The downtime is less than for a full prep, prime, and paint. (Personal Opinion: Hire a professional painter!)
Cons:
In most cases, the primer and clear intercoat are not UV-resistant, so although the plane looks great, it’s not the equivalent of a “permanent” paint job. The plane should be kept out of the sunlight most of the time (. . . a hangar plane; not a ramp plane). The plane should be painted within a year or two (. . . that’s my guess, anyway; maybe some of the pros can help us here).
Unless you want to remove the wings and empennage, you’re committed to a paint job with the aircraft fully assembled (except for the control surfaces, cowling, wheel pants, etc. that are relatively easy to remove/replace).
Other? (I’m sure there are more Cons; I just can’t think of any more right now.)
Food for Thought, Anyway!
Bill Palmer