Temporary Rust Fix - WD-40 or Other?
 

The rear outside wheel wells on my 85.5 are showing some surface rust...and I won't have time to properly address this for awhile.

I really don't think I should hit this area with my grinder until I'm ready to properly prep and repaint.

In the meantime, I'm thinking that I might apply some WD-40 to this area from time to time...to hopefully keep the rust at bay until I have time to really fix this issue.

Or perhaps I should apply some sort of rust eliminator/converter? Which would be best?

The longer you wait to repair a rusty surface the deeper the rust pits will be. You will have to grind more metal off as you have to remove ALL the rust. WD-40 is NOT a temp fix for any type of rust as its major job is to remove moisture from working area/parts. Read the directions on the can.

Cheers,
Larry

Yeah, there's really no quick-fix. Partial-repairs will often cause more severe problems in the future. Sealing in rust anaerobically will actually cause it to spread faster. Look up how ferrous-oxide and ferric-oxide work in tandem.

If you don't have 30-minute to sand down the area, just leave it until you can. Use a small 3" sanding-wheel attachment on a drill to reach the irregular surfaces and remove as much as you can. Wire-wheel can reach the crevices that's not flat. Then use this CRC rust-converter primer to cover the area. Even though it claims "conversion" of rust, that function should only be limited to the small amounts you can't completely remove by grinding/sanding. Then cover with regular sanding-primer before painting.

Wire brush it away, and seal the rusted area with paint or even spray truck bed liner/ under coat... Use tape to make some cool patterns :p

Try this: Stop Rust with POR-15® - We Know What Permanent Means!

i don't know if its avilable in the US, but Ive used Fertan with great success as a rust converter on several cars. Just briush it on even without any prep, and it works

POR-15 will stop your rust cold and it does not any take more time than wirebrushing and painting a couple coats of the rust preventative coating in the red/orange can.

POR-15 Rust Preventive Coating

If you have a picture of your rust please post it so we can advise further...

Can POR-15 be used to coat the wheel wells and underside to prevent rust even if there's no rust to begin with? I plan on driving my '84 in winter as I'll have no other means of transportation. And could it be used on top of the factory coating?

Wash the area with soap, water and a scrub brush. You need to get as much salt and grime out of the area that is starting to rust. Once it's clean you can spray it with a corrosion inhibitor such as as this Corrosion Inhibitor & Anti-Corrosion Spray | Corrosion Protection

Obviously it's best to treat it with a much more permanent solution as soon as you can but this should slow the rust.

similar to POR-15 Automotive Formula - Rust Bullet LLC