How did you rustproof your bottom?

I have been doing epoxy primer then raptor bedliner thinned 10%. It lays out very fine texture when thinned. Of course if your into OE restoration this route is not for you. Grey is epoxy, black is bedliner and thrid pic is close up showing the texture.
Pics are my friends 67 b'cuda im working on.

20201106_213713.jpg

20201107_212505.jpg

20201107_202603.jpg