options for undercarriage rust protection?

[64bawagon]

The rattle cans kind of goop up but you can buy FF in gallon cans then use an air compressor and sprayer. It's still messy, and you have to transfer the product from the can to the sprayer and it doesn't cooperate.

Do all the cars at once, wear old clothes, put a towel on the car seat if you have to move it to bring the next one in. And wear a respirator, it gets cloudy under there and that can't be good for you.

I usually do mine when I am already dirty from something else. I have some clothes in the barn dedicated to mechanic work because you definitely dont want to wear your good school clothes while spraying FF or Surface shield.

 

[64bawagon]

You will never get paint into all the places a rust preventer needs to be sprayed in.

And you want a product that creeps.

A good rip down the interstate on an 80 degree + day will help to even out your application .....

 

[johnmyster]

Similar to you we only have a few salt/brine events a year. I can keep things pretty reasonable with an annual "touchup" on each vehicle. I mostly avoid driving the truck during the winter and certainly during rain following a salt/brine event, until we've had enough rain to clean the roads.

FF and SS both go on sale, so I have a stash of each. FF comes out of the can in a stream. SS is more of a spray. I wind up using both, targeted (suspension points, subframe mounts, etc) vs distributed (frame rails, etc.)

Warming the cans in a tub of hot water before use reduces the frustration factor. I keep a can or two handy for when I do maintenance and see a spot I missed.