Yup! That light bulb went off (on?) in my brain in post #9 last night, and I’m pretty sure that’s exactly what I’m going to do, Jeff!
Nominal dimensions of the building are 24’ x 42’, and the 2x6 trusses are located on 7’ centers. Here’s a picture I just took:
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There are some 2x4’s running perpendicular to the trusses, same spacing. I want to call them perlins, but they’re not on the roof, so I don't think that’s the correct term for them. Regardless, I’ve mounted some 4’ fluorescent fixtures on them as temp lighting…..
Not seen here (above my head when I took this picture) are a few of the existing light fixture boxes located at the junction of the trusses and the “perlins”, and I didn’t mess with them because I thought (past tense) I would copy the spacing of them for the entire building.