So I am going thru my 75 chassis and I'm wondering what are you guys useing under the chassis to keep from rusting? My car has been painted underneath and appears to be rust free for the most part. For example the doors seem solid but is there something you guys spray in the doors to keep the bottom from rusting? And the rear inner fenders do you drill a hole near the shock tower and spray anything in between the trunk inner fender and the outer fender? Any tips in general regarding rust prevention?

I pretreat the bare metal with a phosphate based rust remover, wipe down with clean thinner and then coat with POR15, then use the POR etching primer and topcoat with what I want to use.

I have had good luck with that. The best way I know to keep them from rusting is to keep them from getting wet. Mine has rusted much less in the last 20 years than it did in it's first 10.

As far as coating the insides of panels (in hollow passages), I haven't done much. In the longitudes, I sprayed them with phosphate based rust remover and then sprayed with etching primer in a spray can with a long nozzle on the tip. As long as those areas stay dry, it takes them a long long time to develop rust.


just my $0.02

If there's no rust- just keep it clean and keep it dry. The factory paint will protect it if not over burdoned. If you have rust or bubbles in the paint popping up.. then the rust probably extends much further then what is visible on the surface. Wire brush, or grinder, or chisel, or screw driver, or sand paper is how you start digging in. Once you're there, POR-15 or Zero Rust, or SEM Metal Etching Primer is what you'll probably want to lay down first. Some guys use a rust converter before applying paint.

I'm in the middle of a 'good condition' 73 2.0 restoration.... but there's still rust in every nook and cranny. Rust sucks!