After spending a couple days cleaning out the frame. The inside is now coated with Eastwood Internal Frame Coating. Although I have Fluid Film (FF), I decided to try internal frame coating first. The decision to use Eastwood was partly aided by the fact that a buddy gave me eight cans of the Internal Frame Coating that he bought for his Jeep, but then sold the Jeep before he used it. Also, you can use the Eastwood coating on a frame before FF, but not after. That being the case, I decided to give Eastwood a try first and will monitor it's effectiveness. I started out with two can per side, which was more than enough to soak it internally. I'll go back over it again, with an additional can or two per side, when the weather turns warm again.
To prepare the frame I did the following:
https://www.amazon.com/dp/B07SQYX2FH/?tag=wranglerorg-20This was used to knock any chunks loose internally. I cut the end down a little to allow enough room to add three small links of chain to the end, then used a washer and red locktite on a nut to secure it. You have to run this in a clockwise only mode, so be careful there. Anytime an extension was added, I used a small piece of duct tape to secure it, just in case it came loose.
Hint: It works better to clean out the frame if you support the transmission and transfer case, then remove the skid/s. This way the chain doesn't get caught on the bolts as you push it through.
https://www.amazon.com/gp/product/B01MQ2CZTM/?tag=wranglerorg-20https://www.amazon.com/gp/product/B086MQFPYT/?tag=wranglerorg-20When the chunks on both sides were knocked loose, the tedious task of removing them began. To make this easier, a combination of 22" and 48" flexible magnets was used. Without these the job would have been even more unpleasant than it was.
Once all the big chunks were out, I used an old heater core hose attached to a shop vacuum to get out any of the small stuff.
Hint: insert the heater hose in either large frame hole (front or rear), turn on the vacuum, then use compressed air to blow the particles to the running vacuum suction.
With everything vacuumed out, I gave each frame side one more good blast with compressed air, to blow any remaining particles towards the front and rear.
https://www.eastwood.com/eastwood-internal-frame-coating-14oz-aerosol.htmlWith the frame cleaned out, the frame was taped in sections and sprayed with the frame coating. When doing the spraying there were a few tricks to help:
1. The supplied spray hose is coiled up when you get it. I used a heat gun to relax the hose and make it straight. This ensures you get a good even spray coating internally.
2. Make sure the frame is supported with 6 ton jack stands and the tires are removed for easy spray access.
3. Cover the floor with lots of paper, especially on the front and rear ends of the frame. This stuff will pour out of the bottom of the frame and make a mess if you don't!
4. Once you put everything back together, move the vehicle outside to let it dry. This stuff stinks up the garage and will out gas for 24 -48 hours.
When it was all done, I probably spent more than 12 - 15 hours on the job. The bulk of the time was consumed on cleaning debris out of the frame. The better job you do there, the more likely the job will be successful at fighting future rust!
I really like your Jeep.