Underside of floor coated with 3 coats of marine epoxy. The last two have graphite mixed in. Works on the bottoms of my wood boats, so I figure it should be good here too.
I find your cost tally interesting. I was worried that I was overspending. My costs are in line with yours. I guess stuff just adds up fast. So many little things go into one of these builds. Keep up the good work.
I am not looking forward to adding up the recipes. It's going to be scary. I told my wife we can build for $5000, she planed on $10,000. She has seen how projects get grow, from "Lets paint the bedroom" while I'm walking in with the sawzall.