Ultimately I gave up on chemical rust removal. For one thing, it didn't fully remove the rust. And as you can see, unless i built a tank and fully submerged the parts, there were sections of baffle that couldn't be treated. I tried soaking rags and other things. But I wasn't happy with the result. Lastly, I read that the coating I chose would adhere better if there was some surface roughness. So I bead blasted the tank halves.

With the majority of it cleaned up, I tackled the screen. I drilled out the spot welds to separate the canister and cut the suction pipe to remove the screen.

The screen was almost completely clogged with fine particles of rust. No wonder fuel wasn't getting out. I carefully cut the screen out.

You can see the small pile of debris that was stuck inside the screen. The screen itself was so fine it felt like linen.

Edited 10 hours ago10 hr by the_tool_man
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Now for the rust-preventative coating. I knew that if I hand-coated the parts, I'd have to leave an uncoated area near the seam for welding, and then slosh more coating in the tank afterward to cover the seam. I reached out to the manufacturers of several tank coatings. Knowing I would end up with two layers of coating in parts of the tank, I asked for their recommendations. Most advised against it. One supplier, Red Kote, specifically says in its literature that it can be recoated. A phone call confirmed that it would be fine. So that's what I used.

I used a brush to coat the halves, leaving bare metal where they would be welded together. The stuff is thick, like molasses, and thickens in minutes. So I had to work quickly to get an even coating.

Then we could reinstall the pickup tube (also coated), minus the screen. I made a sleeve from a scrap of stainless tubing and got a friend to braise it together.

Then I tackled welded the top half of the canister back on.

I touched up each joint after allowing it to cool and giving it a good cleaning. Red Kote smells and acts like PVC pipe cement. It puts off some serious fumes. Acetone is the recommended solvent for thinning it. So I used that to clean each surface immediately before coating.

I didn't trust my ability to hermetically weld the tank. So I assisted a friend while he tacked it together. He then took it to a mutual friend with a TIG welder and finished it up.

At this point, I poured more Red Kote into the tank and allowed it to flow over all of the seam. I let this sit for about a month to cure.

Then, I sealed off all of the openings and blasted off the remainder of the external paint. Interestingly, there were dozens of small hidden rust spots beneath the paint. You couldn't see them through the paint. But when the media hit it, the paint would flake off, revealing a brown rusted spot. After blasting, ready for paint.

I primed and painted it with Rust-oleum automotive paint in rattle cans. It turned out decent. No one will be looking at it. Note I didn't remove the original rubber blocks. They were stuck on really well, and not damaged. I did remove the original foam rubber piece near the sender hole because it was falling apart. I replaced it with a similarly-sized piece of 1/8" (3mm) thick EPDM rubber, just to make sure nothing would rattle.

You can also see where I masked off the factory marking, just in case anyone might ever care if the tank was original. Lastly, I leak tested it by putting a few gallons of gasoline in it and allowing it to sit on each edge for 30 minutes. The sun was out, so the tank heated up and pressurized, which was a good sign.

I'm happy to report that I've reinstalled the tank in the car, and it works fine. No leaks. And no more plastic gas can bugeed to the rear shelf.

Edited 10 hours ago10 hr by the_tool_man
Added last photo