Best rustproofing methods for underneath?

[SkipMorgart]

Howdy...hopefully I'll be getting my astro soon, and I want to rustproof (as much as possible) underneath when i get it. I know to wire brush first, but what materials do you people recommend to "rustproof" and seal the underneath? Thanks in advance.

[Rudedaddy]

I own a 2001 safari cargo van and I can say I rust proofed the bottom of the van myself with this FORMULA 2000 ( $11.99 ) a spray ( black / silver can ) that works very well for me ...from CANADIAN TIRE.... It stops the rust in it's tracks it stays moist and lasts up to 7 years with touch ups... Two or 3 cans it took to do all the underside , doors and wheel wells ....I have tried a few products but this one works best...

[CaptSquid]

Best one? Move to an area where salt is NOT used on the roads.

[Captn. Crunch]

I use penetrol. It's an oil paint additive. It penetrates rust and stops the oxidation. You can put it directly over heavy scale-no scraping. Simply re-apply the heavy scaled areas as the heavy stuff will slough off by itself. I use my HVLP paint sprayer. Being a painter and having the stuff laying around helps but do yourself a favor and read up on this stuff on line it's pretty amazing and cheap!

[spudman]

Using the penetrol, do you spray it on by itself, or do you have to mix it with a paint ???

[LiftedAWDAstro]

The absolutely best stuff I have found after there is light rust, is Fluid Film. It goes on wet, almost waxy and stays that way forever. It is very hard to wash off and creates a moisture barrier and works as an awesome lubricant.