oil undercoating question
 

So, i just moved to vermont from wyoming and i have brought my '89 runner with no rust with me. now, they salt the hell out of these roads here, and i am afraid that it'll eat though my 20 year old steel pretty fast. i have had some people tell me about oil undercoating and i have heard some good stuff about using grease to do it instead. it's more expensive, but supposedly works better.

if i could get some opinions on what you do to avoid the rot, i'd appreciate it.
Thanks
~sb

I've done the back half of my frame in POR-15 and will do the front half soon. For the inside of the frame I'm going to use Fluid-Film which comes in a spray can.

Coat your frame now while it's in good shape and you'll be fine.

If you want to do the inside, apparently people have had good luck spraying boiled linseed oil mixed with a carrier like WD40. Mixed together, then sprayed with something like a pesticide sprayer you might be able to coat the inner frame rails.

Now, to be clear, I've never tried this myself. Google and you might find better examples of what I've just mentioned.

i get my hilux surf crown oil sprayed and am gonna do it every year... the city gets all there trucks done there!

After looking on the Fluid Film website, it says a hand-pump pesticide sprayer doesn't have the pressure to spray Fluid Film. The website recommends 80-90 psi.

Wonder if I can jerry-rig something with my on board compressor.

that's what i was thinking... of having it done somewhere by a professional. most people i know get it oil undercoated, but has anyone had any experience with the grease undercoat? if not, no biggie, but i was just wondering.

Krown is about the best you can get IMO... and they give you a warranty... cost for a small pick-up/suv is under $150 and well worth it.
Oil under-coat is best because it can "creep" into all the nooks and cranies where grease only hits the surfaces it is sprayed on.
If you get an oil spray job don't park on your driveway if you have paver stones for about a week after the application you will be dripping oil til about then and it will stain the pavers. It will also leave stains on asphalt but at least there you can cover it up with some sealer lol...

Get it done now for sure but for future reference Krown recommends an application be done around March because the spring thaw is when there is a whole winters's worth of salt dust and brine in the air from the melting snow drifts and the corrosion risk is highest.

The oil thing does work, but consider this... u spay with oil, and now everything u sprayed is sticky, and wet, the first time it snows, you are gonna have all that salt and sand clinging to the oil.
It will work, but u gotta do it more than 1 or twice a year....trust me.
I used to go this route, using used motor oil, ever couple weeks thru winter, the frame, and under carriage in my truck are immaculate, especially compared to my 94 which has never been sprayed.
That being said... I now do the por15, and rubberized undercoating thing, at least that way, u dont have to worry about all that stuff clinging to ur metal.


My $,02

i can't speak for other products but the Krown oil spray is not used motor oil, but an oil suspended rust inhibitor product. So far as sticky-ness is concerned yes the product is sticky when in protected areas like inside doors and body panels where it stays a little wet but on exposed areas like outer frame surfaces and such it seems to dry to a protective layer in relatively short order. I've never noticed any issues with road grime sticking to protected areas anymore then is normal ie slush on rocker panels and so forth.