travist wrote:...
So the question is: should I go to the extent of disassembly so that I pull up the plywood and paint it, or just paint it from the underneath. I guess I'm wondering if missing the spots where the studs are underneath is a big deal.
* I used spray can automotive undercoating on my TTT. That way, I could cover the underside plywood deck, frame, and any exposed bolt heads or nuts at the same time, without the mess of the dripping brush-on black asphaltic stuff many people use. The spray-on (rattle-can) application is easy, even without lifting the trailer (be sure to wear a mask, eye protection, and maybe a head covering (my white hair got darker, somehow, while using it). It dries almost instantly, so you can do several layers at a time. You can quickly re-coat, if you need to, anytime, anywhere, if you keep a spare can handy.
* I used several brands, they all work together the same, depending what auto supply, big box store, Tractor Supply I was near, over many years of modifications, where I would add or remove thru-floor bolts, and needed to re-touch. Rustoleum, Duplicolor, Krylon undercoating, even Herculiner bed-liner, all do the job. None has ever come off, or let water thru.