^^ This is the floor pan, of my 2005 Jimmy 4x4, that gets winter snow & salt spray in the Ontario Canada rust belt, vehicle not garaged.
- SUV was oil spray undercoated, for the first decade / yearly application
- oil spray buildup is still protecting & caked on frame rails & sheet metal floor pans
First spray application, high pressure wash underneath (if necessary) and let it dry completely.
(I don't bother with rust converters, during oil undercoating)
- Wax-Oil will penetrate & seal the existing rust and slow it down considerably / properly shielding rust from any oxygen, can literally stop it in its tracks
In my experience, wax-oil undercoating products are best / like Fluid Film.
(some products are water based & can be sprayed on a damp vehicle / I avoid them, as they quickly wash out and disappear)
- Ziebart type rubberized coatings, tend to dry out and crack / major FAIL
- than salt and moisture is trapped under the coating & speeds up rust
I get my used 2008 RAV4 Lmited and used 2000 4Runner SR5 oil sprayed, before winter sets in.
- will have spray redone every fall (from now on) & the wax-oil formula will start to build up nicely
- on undercarriage and inside door and fenders
http://www.webmallnumber1.com/ptauto/dura.html
My 1989 Nissan Pathfinder is long gone with high mileage - OIL undercoating is proven & clearly works:
- I bought this 4x4 used (3 years old) and owned it for another 14 years / driven daily
- never garaged, always parked outside overnight / often on a snow covered paved driveway
- kept it virtually rust free with annual oil spray undercoating
- sold it because it didn't have AC or PW/PDL's
- but I still go a pretty penny for it, because the body & frame was really solid
- oil spray has a real good ROI, and I always enjoy a decent resale value, selling my older vehicles