lather, rinse, repeat
Yesterday I did another run of the Marine Clean in Peanut's gas tank. I was smarter this time and started early (well, I consider 11:30 am to be early), which got me done by 11:30 pm. I also used some aluminum tape this time to seal the tank completely so that all of the Marine Clean stayed inside the tank at all orientations. When I poured it out, it looked rust-colored, with no visible dissolved goo or anything else. This means on to the next step -- de-rusting. This run is 1/2 hour on each side, which adds up to 3 hours total, after which I have to make the tank "bone dry." This will probably involve attaching a hair dryer to the fill neck of the tank with some more aluminum tape and running it for several hours, constantly checking to make sure nothing's on fire.
I just got my order from POR-15 today. I was surprised not to see any "hazardous material" markings on the boxes, although they did ship it UPS ground.