Oil as undercoating to slow down rust
- Thread starter OM605
- Start date
wemay
Site Donor 2023
Oil is one of the products used in the comparison...
Well for the sake of the environment use the right stuff like Krown or Fluid Film or similar. Dumping oil (used or new) will eventually get the oil on the road or ground and pollute wherever it ends up. If everyone in the world sprayed oil on their car the world would be an oily mess.
The proper product will creep and fix areas where the product got scratched or washed off.
JHZR2
Staff member
The issue is that in some enclosed areas where water stands, some of these products can lift or flake.
BTDT with my experimentation with cosmolene in the doors of my Dodge Ram.
What is "BTDT"?
JHZR2
Staff member
Been There, Done That
I'll know that next time round! Thx!
x2 on Noxudol. Noxudol 300 for chassis and 700 for cavities. It’s the same product Toyota, Isuzu, etc. have used for corrosion related recalls and mitigation. Stays soft, does not wash off and contains active chemicals to stop corrosion. Noxudol 700 (for body cavities) has excellent creep characteristics and stays active for a long time. I’ve tried a lot of different products over the last 35 years or so (heavy winter salt here) and nothing works better. Krown and Rust Check wash off within 1 -2 hours driving in rain. Fluid Film is a bit better, but still washes off far too easily in winter conditions.
Minor touch ups are all that is required yearly…It’s a bit more expensive on first application but rapidly pays for itself in subsequent years.
Minor touch ups are all that is required yearly…It’s a bit more expensive on first application but rapidly pays for itself in subsequent years.
This is the main reason I only purchased 2 new vehicles in the almost 40 years I lived in and around Chicago. There is simply no way you can own and drive a car there, and keep it from turning into a bucket of rust.
Today's cars are better at fighting it off, because of the use of more plastics, composites, and things like Stainless Steel exhaust components. But any vehicle sentenced to operate in Midwest Winters is going to rust away. It's only a matter of time.
Things like undercoating, (you pick the product), repeated washing and waxing, "rustproofing", (Companies like "Ziebart", and "Rusty Jones" took a lot of people's money there back in the day), all with little to no effect on long term rusting and body cancer.
The best way to keep a vehicle in nice condition in the "Rust Belt", is to park it in the garage, and buy a beater to be self sacrificed as your daily driver during those conditions. Especially when you factor in what a nice, new vehicle costs today.
Cosmoline is the one product I never tried, but admittingly should have when I lived in that climate. I think it's waxy toughness, and it's ability to stay put make it a good choice.
The military stoired weapons coated with it for a good reason. However, like with most products when used in the automotive world, it would require reapplication.
Woolwax is a thick lanolin based undercoating that works great. I use the black, it looks very nice and goes on thick. What may wash off over the year can be easily seen w the black and you know where to apply when touching it up the following year. Woolwax is a bit thicker than FluidFilms and lasts a little longer.
I haven't see that with the Cortec product I've been using. But flaking can happen with some products for sure.
M119 you are so lucky your roads are not salt srapyed!
If you live neat the sea, be aware that sea breeze is just as deadly as salted roads
Oil film will provide protection against corrosion. But will wear off quickly in 50%+ humidity even if you don't use your car.
You can use thicker oil like gear oil which will last longer. They will both collect dirt dust & grime as well!
Here is what I did:
clean the underside of the car (snow foam or similar) drive the car, then let it air & dry for a day.
Used rust blocker spray
Used underseal with waxoyl in it.
The important point is to saturate the rust with product like waxoyl which will stop it from being exposed to air. Unfortunately waxoyl despite being great at combating rust, need a top coating at it is not strong and stays sticky.
If you live neat the sea, be aware that sea breeze is just as deadly as salted roads
Oil film will provide protection against corrosion. But will wear off quickly in 50%+ humidity even if you don't use your car.
You can use thicker oil like gear oil which will last longer. They will both collect dirt dust & grime as well!
Here is what I did:
clean the underside of the car (snow foam or similar) drive the car, then let it air & dry for a day.
Used rust blocker spray
Used underseal with waxoyl in it.
The important point is to saturate the rust with product like waxoyl which will stop it from being exposed to air. Unfortunately waxoyl despite being great at combating rust, need a top coating at it is not strong and stays sticky.
We live in the worst of the salt belt with salt/sand literlaly sand blasting the chassis 5-6 months a year. I also keep vehicles a long time. I recently sold an 1984 Scirocco and 1990 VW Westfalia. Both were driven in winter and both were in excellent shape.
The key is the right product, applied well (the franchise shops I've used have all been crap with respect to coverage) and maintained yearly. I also go over our cars each spring and address rock chips etc with some prep and touch up paint. Over the last five years I've set with a decent set of cavity spray tools, and have the luxury of a hoist in my shop. It takes about 5-8 hours of labour on each car to the do the first treatment which includes a thorough spray wash of the chassis, drying, and then pulling off fender liners, chassis shields, and some trim bits, lights etc. to get at critical areas. This is what Noxudol 300 looks like after four years. You can see I have just applied a bit of touch up on the rear suspension which gets beat up here after a salt/sand winter. This last winter was a record setter with respect to both cold and snow for us.
There are only two products I've ever found that contain actual corrosion inhibiting additives along with the carrier. Noxudol 300/700 and Noxrust 712 AM, both used in Toyota's various frame/rust recalls. They are wax based, and water borne for application.
I'm about 100% positive that the Toyota engineers chose these materials because they are easy to spray, don't swell rubber (like lanolin based FF and Woolwax), don't wash off and actively combat corrosion. Internally, the material is there for the life of the vehicle. Externally, you'd need about 200-300ml per year to touch up areas directly impacted by wheel wash.
This 3 year long term test is about dead on with my experience...but I'd add that the Noxudol 300 (applied to exposed chassis) is about as good is gets resisting sand/salt "blasting" that a road car sees in our climate. This test was with respect to the Noxudol 700 https://www.auson.se/wp-content/uploads/2020/03/rusttest_noxudol_700_classic_monthly_uk_1.pdf
The 700 creeps 5-7 inches after application, and in that long term test was shown to have reacted with existing rust to stop it.
I use Fluid film on my snowblower for summer storage, but it is gone (from the auger/chute area) after pretty much the first snowfall. On the outside of the blower, it's ok as it does not see much in the way of wash during a winter. There are no seals/rubber that I'm worried about on a snowblower either. I don't use it on our cars anymore.
Last edited:
If you can get Fluid Film or Woolwax in France I would go for that. My next choice would be the chainsaw oil because that usually has a tackifier which will help it stick.
I bought a 5 gallon pail of the black dyed Woolwax and can say the stuff goes on thick and sticks well even after a full year. I can see a few spots that did wash off over the winter which I'll be touching up this month, but I can see paying a little more for the dyed version is going to help avoid going over areas that are already coated.
I would avoid spraying used oil not only for the environmental concern but due to the fact that it is a known carcinogen. I wouldn't want to be aerosolizing that and potentially getting it on my skin if I didn't need to.
I bought a 5 gallon pail of the black dyed Woolwax and can say the stuff goes on thick and sticks well even after a full year. I can see a few spots that did wash off over the winter which I'll be touching up this month, but I can see paying a little more for the dyed version is going to help avoid going over areas that are already coated.
I would avoid spraying used oil not only for the environmental concern but due to the fact that it is a known carcinogen. I wouldn't want to be aerosolizing that and potentially getting it on my skin if I didn't need to.
