So I got after it today and started removing hatches and windows. Found more, but it seems to be somewhat lower on the back wall. Good news the floor seems ok. Bad news, the jack reinforcement is not.
PDF Picture tour of my soggy BigfootGood news:
1. Grant at Bigfoot was super responsive (on a Sunday) and very helpful in describing the construction and thought on how to repair. Keep in mind this is a 19 year old camper that was built by the previous incarnation of Bigfoot...he provided better support than most companies do for new products. So I am bummed, but heartened that Bigfoot supports their products.
2. SIPS construction seems pretty straightforward to fix. Remove/replace rotten core and rebond inner and skin/outer shell to core.
3. I am already feeling more confident that I can do this. Everything came apart very easily. I am going to reseal EVERYTHING.
Bad news:
1. I have to pull the generator and remove the heat shroud to see how high the rot goes on the passenger side. All jack screws were rusted.
2. I have no clue how I am supposed to rehab the driver's side jack backing without removing the entire 1-piece bath. I am open to ideas. I would really rather not start disassembling the interior if I can help it.
I have ready about people injecting epoxy to fix cores in boats but apparently that really only works for small volumes. I am thinking stick a line in the top jack mount hole and draw epoxy (or polyester) with a vacuum pump to each of the holes until some come out. That might just make a massive mess that is darn near impossible to fix though.