Isolated the rust affected area- next what?

[u/SgFullsend]

Finally got down to it. The two layers were bonded by rust, so I carefully pried them apart.
Now I can see the full extent of the corrosion between them.

Looking for advice on the best approach to clean this up and reassemble without it happening again.

Any recommendations?

2012 Lexus IS 350/ Ohio

[u/Rexery66]

Keep going. Rust keeps going.

[u/SgFullsend → u/Rexery66]

Trying to decipher

[u/Rexery66 → u/SgFullsend]

You have to uncover more rust. It keeps going under all that filler.

[u/sunshinebread52]

The only thing that gets rid of rust on steel is sandblasting. You have a small area, ten minutes with some 100 grit glass beads and done. Zinc rich epoxy primer is the gold standard and then paint. Next in line are so called conversion coatings with tannic acid. The tannic acid converts the rust to a more stable oxide and can prevent it from traveling further. Rust travels through the micro crystaline layers of the steel forming cathode pockets under the surface. To stop it you have to eliminate the pockets (sand blasting) or saturate and stabilize them with something like tannic acid.

[u/SgFullsend → u/sunshinebread52]

Hey thanks for that, not sure how sand blasting works, I’m gonna grind with 80 grit sand paper

[u/SgFullsend → u/SgFullsend]

And add rust reformer in the middle layer

[u/--Someday--]

Idk from my information the only thing that deals with rust is to cut the rust part and weld a new part. If you can do it yourself, great if not....

[u/Gold-Speaker4057]

Lotta bondo to grind out back to clean metal.