Finished up the tailgate & feel confident I met the goal of preventing further rust damage for the foreseeable future (fingers crossed). Notes & pics:

The factory material is very difficult to remove unless there’s rust under it, in which case mine flaked right off. So that’s a good test. I used a metal putty knife to remove it and tapped the bottom of the scraper handle with a hammer to get the tougher spots. As noted in my previous post, be sure you get all the pieces, flakes, & dust out of the bottom of the tailgate lest it block the drain holes. I used my hands to get the large pieces like the one below, then a ShopVac followed up by compressed air.

Front (visible when looking into the tailgate)


Underside


Dust & particles collect at the bottom. This is after most had been removed. Get as much of it as you can.


I scraped, grinded, & wire brushed the rust until nothing else was coming off then painted with rust reformer.


I wanted secondary corrosion protection besides the Rust Reformer paint. Considered undercoating & PlastiDip but ultimately chose Fluid Film:


Decided to do my sound deadening while the hatch was disassembled. I reinstalled the plastic factory vapor barrier and covered it with a foam board piece that I waterproofed with Flex Seal.


Attached it with metal HVAC tape but forgot to get a pic of it installed.

Final step was adding Noico Green to the inside of the hatch trim. Haven’t gone anywhere yet so no report on whether it’s quieter now.