Teach me about rust prevention

I'm a small-budget kind of guy, which means I often buy vehicles with cash in the $4000-8000 range which means they are usually mostly rust free when I buy them, but they are right at the point where the four years I own them they devolve into swiss cheese and I have trouble selling them.

I'm thinking about a low-mileage 03 Ford Ranger, and also considering a very low mileage 93 Tacoma.  This time I want to do things to prevent rust as much as possible since they are both mostly rust-free right now.

So what do I do?  Take it to a used car lot and have them do their magic barrel-o-undercoat thing?  Buy a case of rattle-can undercoating?  Do a professional rust proofing thing like Rusty Jones?  I thought about spray on bedliner, but that stuff is expensive.  Doing the whole underside would be pricey.

Ideas?

Most rust begins in the places you can't see. Fluid Film makes a long flexible spray hose with a 360deg nozzle that just pops on top of the can. You can snake it down into the rockers, the bottom of the doors, etc. and cover those surfaces. I only learned about it within the last few years, but I've got it and it's easy to do. Wurth and Waxoyl make similar products.

It took me four decades of research living in the rust belt that is Upstate NY but I did come up with a solution to the automotive rust problem.  I moved to New Mexico.  Seriously, though.  I never found anything that was worth the money and effort.  I finally settled on buying the most rust free vehicle I could afford,  washing it as often as practical and using the rust as an excuse to buy a new (to me) car every five to ten years.

Fluid film kicks ass.

Been using it for about 10 years. It makes an oily, sticky mess but it sure keeps stuff from rusting.

Every motorcycle and bicycle I own gets a squirt inside the frame tubes too.

Very Big mud flaps help too. They keep some of the road spray from getting under the doors. Use existing bolts to mount them rather than making new holes.

Another fan here if fluid film and regular  washing, also in PA.  My 03 Suburban with 168k has no significant body rust, while most on the road seem to have no rockers left.  Same with our 07 Mazda3 with 219k.  I have the fluid film gun and wands and whatnot.  It takes 3x as much stuff and 3x as long as our Mazda3 as there are so many nooks and crannies to get the fluid film into compared to a unibody.  

I am certainly no rust expert considering I live in CA, but I think there is a bit of concern with coatings in that you will either keep rust from starting, or trap water and assure it will start since it cannot get out.

aircooled said:

I am certainly no rust expert considering I live in CA, but I think there is a bit of concern with coatings in that you will either keep rust from starting, or trap water and assure it will start since it cannot get out.

I think that's more of a concern with traditional undercoating than with products like Fluid Film, which is more of a viscous, oily liquid.

Every vehicle I own gets mudflaps, and I use FF. I also wash often, and for my first hand wash of the year I give the undercarriage a a bit of a hows-your-father with my pressure washer, as well. 

It's a losing battle, of course, but that doesn't mean I'm not going to fight as long as I can.

Oh yeah, last fall I bought a cheap little pot metal sprinkler head for the hose. It sprays up in a fan pattern, and a few times a winter I hook it up and drag it under the car to wash all the salt and debris off. I was surprised just how long it took to see clean water running out from under there.

Bought me two extra years on a Mazda Protege5 that already had some rust started.  Since the tin worm gobbles P5's like Michael Moore in a Crispy Cream, I consider that a pretty solid product test.  Super easy to apply and not stupid expensive either.  I just did the most rust-prone areas and only needed a pint, but my barber did the whole underside of a Jeep with a half-quart worth of product.   The only real down side is if you get it on your skin, you're gonna wear it for 3-4 weeks.  

I go to the local touchless car wash that includes an underbody spray for the $6, and drive over the underbody spray very slowly 

kazoospec said:

Bought me two extra years on a Mazda Protege5 that already had some rust started.  Since the tin worm gobbles P5's like Michael Moore in a Crispy Cream, I consider that a pretty solid product test.  Super easy to apply and not stupid expensive either.  I just did the most rust-prone areas and only needed a pint, but my barber did the whole underside of a Jeep with a half-quart worth of product.   The only real down side is if you get it on your skin, you're gonna wear it for 3-4 weeks.  

I dipped my ponytail in that stuff once painting the underside of a frame.  My wife at the time lovingly got most of it out with acetone until she got high, then realized that teh acetone had pretty much eaten my hair.

02Pilot said:

Most rust begins in the places you can't see. Fluid Film makes a long flexible spray hose with a 360deg nozzle that just pops on top of the can. You can snake it down into the rockers, the bottom of the doors, etc. and cover those surfaces. I only learned about it within the last few years, but I've got it and it's easy to do. Wurth and Waxoyl make similar products.

Thanks for all the recommendations.  I'll see about getting some.

I sold my truck and we're meeting at the notary tomorrow, but I haven't found a new truck yet.  Hope the Impala starts, or at least I can take the motorcycle if it isn't raining.

Add me to the Fluid Film club.  It really does work great but you have to reapply.  It isnt a one and done product.  I bought the kit with the different wands to make it easier for all the nooks and crannies.

Whats the thought on touch up paint on the underside?  I could see it done yearly making a big difference on keeping the chassis looking fresh.  VHT has a really nice satin black epoxy chassis paint, I plan on pressure washing and touching up all the raw/plated areas under my new rust free Land Cruiser before salt driving.  Also looking at Fluid Film or Waxoyl.  

Any good places to buy all the spray guns and nozzles for all this?

I got mine all in a kit with 2 gallons of FF from Amazon. 

My buddy Jefferson did an article on using Herculiner to undercoat one of his project cars:

http://knowhow.napaonline.com/101-uses-for-bedliner-undercoating-your-car-with-herculiner/

Here's the thing about rust that many don't know.  Rust feeds itself.  You can't just cover it.  You have to remove it (hence why it's called cancer)

There are two forms of rust:  Fe2O3 and FeO2 with a few dozen sub formulas including hydrogen.  The FeO2 is the stuff that happens really quickly like if you spray water on bare steel.  It gets that light red surface rust in a matter of hours.  If you just cover up rust, the FeO2 has enough oxygen to spare that it will create Fe2O3 which is flaky crusty stuff.  This is why you can't just cover rust, you have to get rid of it.  Even if you seal it with Rhinoliner, undercoating, or POR-15, it will continue to grow.

The analogy for rust my chemistry professor used was; if you have a filet of salmon and want to stop it from rotting, you can't just put it in a vacuum bag and leave it on the counter.  The bacteria is already in there.  It will keep rotting even though you sealed it up.

Hoping to piggyback on this thread.  I’ve used fluid film on used cars to slow down corrosion, but I now have a new car I’d like to keep nice, and am willing to spend a bit extra to have it dealt with by someone who knows what they are doing.  I’m in Ohio, but a bunch of my coworkers in the Toronto area swear by Krown rustproofing.  Anybody used it, or anyone work for a shop that’s applied it, and have any opinions?  As I understand, it’s applied once a year?

Keep it clean, POR15 as necessary, Krown once a year, touch up rock chips ASAP. 

eastsideTim said:

Hoping to piggyback on this thread.  I’ve used fluid film on used cars to slow down corrosion, but I now have a new car I’d like to keep nice, and am willing to spend a bit extra to have it dealt with by someone who knows what they are doing.  I’m in Ohio, but a bunch of my coworkers in the Toronto area swear by Krown rustproofing.  Anybody used it, or anyone work for a shop that’s applied it, and have any opinions?  As I understand, it’s applied once a year?

I had the Krown rustproofing done when I got my 2 year old frontier. For the most part it looks like it would do the job. Of course it’s only as good as the guy doing the job. Having a lift allowed my to see a few areas that he neglected to coat. Mainly the flat sections of the underside of the bed and the radiator support. This and the fact that the only Krown shop was 45 minutes away is why I decided to use FF and do it myself. I need to get a spray wand since it’s cheaper by the gallon.

CarKid1989 said:

Any good places to buy all the spray guns and nozzles for all this?

http://www.tptools.com/  edit: carkid- This is about 90 minutes from you.

or any car paint supply store.

What I've found is just don't drive that car in the winter. It works! 

I had a 1988 Ford van. Now they are known for rusting everywhere.  I bought it in 2002 from a guy that didn't drive it in the winter and then I didn't either. I sold it last year and the only rust was some surface rust on the body where rocks had chipped the paint and some on the frame.  And I parked it outside too. Paint was faded but it wasn't rusty.

I know that it's not practical for everyone to do this but I had to put it out there.

jimbbski said:

What I've found is just don't drive that car in the winter. It works! 

Truth.  Unfortunately, I can't stay at home for 4 months.  I run out of beer.

The 67 LeMans goes in the garage after the first salt and doesn't come out until at least two good spring rains have washed the roads.