Hey, guys! I'm just checking in. I examined my frame on January 3, 2023, and the Eastwood internal coating seems to be working perfectly. So this entire procedure of adding or enlarging a few carefully thought-out holes, blasting the inside of the rails clean, and then using the Eastwood product was worth all the thought and effort. I am very pleased with this, long-term.
My only suggested change/addition would be to see whether the interior of the frame rails can be dry ice blasted after being modified and blasted out with the clog hog. I recently saw this done and it leaves ZERO residues. It is not as effective as media blasting with something solid, but it is still very good. And it all disappears/melts to leave a very clean surface. I would blast it out with the clog hog a second time afterward to ensure any rust particulate is removed, but that is just me.
Also, a friend showed me how he HEATS the frame rails to dry them out. He does a lot of river fording and is anal-retentive about his TJ frame. He blasts it out with clean hose water and then leaves the TJ in the sun to dry out. However, in the winter he has noted that the water will still be in the rails for several days. He has some fancy-schmancy heater "strings" (I did not ask him what they are called, but they are some sort of aircraft tool, and probably expensive) that he runs in one end of the frame and out a side hole, one section at a time, and they are waterproof and get pretty hot. You fish them in the rear and over the wheel arch, out that large side hole, and then warm that section until the water has evaporated. He has six of these, so he can do the front, middle, and rear of both rails at one time. It takes about two hours on a cold day.
I asked him why he did not just coat the frame as I did. He said that here in the Deep South, we did not need to do that. Whatever. I did, so I did it. His heaters would be perfect to use after washing out the frame, but before the Eastwood gunk is sprayed inside. If you spray it into a frame rail with standing water droplets, they will be forever encased between the gunk and the steel. I think that eventually, these will rust all the way through, but with no oxygen, it would probably take a very long time to do so. Anyway, the idea of heating the frame rails to ensure they are DRY is a good one, though probably not necessary. I am just alerting you to the existence of this heater cord my friend has.
One last note: The Eastwood coating that I accidentally sprayed onto my carport slab years ago looks like it happened yesterday. That nasty green stuff is tough!