[Denverbillsfan]

I was thinking of having my Rav undercoated. I have read pro's and con's. The last post on this site was back in 2012 so i am hoping there have been some improvements since then. I have been back in chicago since 2009. I didn't need this in Denver where i bought the car as they don't use salt.

Has anyone done this, if so do you recommend it?

 

[DVS]

In the winter they sure use salt where I am, and I had that done to my RAV, ***but*** I had it done by the dealer when it was brand new (I think it had less than 10 miles on it). So basically it did not have a chance to get foreign materials up under there, rust starting, etc. before the rubberized undercoating.

I don't know how effective it might be on a vehicle that's been exposed to the elements for years before applying it for the first time.

Only time will tell. I don't regret having it done, and can only hope that it helps keep the rusties at bay. I think it came with a 10 year warranty, if I recall correctly.

.

 

[KSNancy]

Right, for a car that's been around a while clean the bottom thoroughly and treat any rust (like with rust conversion primer) before undercoating.

 

[Denverbillsfan]

That was one question I was going to ask the shop. How do they prep the bottom of the card for the application. I would think as long as it's washed off with no moisture or salt remaining that the application should go smoothly.

 

[kyoo]

keep us posted - I may do this myself manually - wash it down, hit with rust converter, and I've got that rubber undercoating in a can deal.

 

[Beaumont67]

^^ 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

 

[vanib]

In Ottawa, the best deal is Canadian Tire. They use Corrosion Free fluid for $50 for the undercarriage. Their "ultimate" package is a rip-off though. I just buy a can of Fluid Film and hit the bottom of the doors myself.

 

[Beaumont67]

In Ottawa, the best deal is Canadian Tire. They use Corrosion Free fluid for $50 for the undercarriage. Their "ultimate" package is a rip-off though. I just buy a can of Fluid Film and hit the bottom of the doors myself.

^^ Both excellent oil undercoats / I got turned off of the popular Krown &/or Rust Check type franchise sprays, as I believe they are water based & quickly wash off.
- I rented a hoist a few times, 20 years ago to undercoat my own trucks
- used Krown, bought it by the gallon
- a month later, my wheel wells were absent of the undercoat / and I had applied it very generously

This is the door corner of my mint 2000 4Runner SR5 / SUV always Ontario driven.
- Toyota is known for not having drain holes in the bottom of their doors, to displace rain and moisture / seam factory sealed pretty good
In order to prevent these doors from corroding from the inside/out:
- I use a step drill making a small hole on the vertical door frame, allowing a spray wand to enter / thereby fill lower cavity of door bottom, with a good dose of wax-oil mist...keeps crimped door skin steel panels from not expanding or getting cancerous on outside sheet metal, seams remain tight and free of rust, for decades

 

[Biostrom]

Cosmoline undercoating is excellent, helped my 2000 Nissan Xterra survive 15 winters in western Maryland, where salt usage/mile is unparalleled. A rich state with a portion that receives 100" of snowfall annually, so we have a bottomless pile of road salt and huge fleet of applicators. Idiots....

I use the military grade version in a spray can found at: cosmolinedirect.com

One feature is a self healing property where warm temps cause the material to melt a bit and fill in nicks. Do not high pressure wash treated areas though as it will remove it.

 

[JuneBug]

- Toyota is known for not having drain holes in the bottom of their doors, to displace rain and moisture / seam factory sealed pretty good

My RAV4 definitely has the drain holes at the bottom of each door--I have a photo in a post somewhere on here. Sometimes those holes get plugged with dirt and leaves which causes moisture to stay and form rust. When washing a car it's a good idea to clean those holes with a small brush.