Rust prevention

[jmk]

If you do decide to think POR-15, make sure you use urethane grade solvents, otherwise you may get gelling in the gun on top of poor performance.

[JiveTurkey]

What part of North Carolina are you in Wolf? We could pool our labor and do both of our cars at once if you're close enough for me to tow out to you.

[Graham]

Originally Posted by Equitas

What are people's opinions about using a rust-prevention product (like Rustcheck) to keep a car that presently doesn't have rust, from getting rust if driven in a "rust belt"?

I presume that it would devalue a collector / concourse car.

However, a daily-driver...any downside?

I use Krown on my '98 E320 and '85 300D. Also used it on a '95 Tahoe that had zero rust when it came to an untimely end. You need to do it every year.

POR-15 is a one part polyurethane that cures by absorbing moisture from the air. The surface cures very hard. Any moisture that tries to reach metal is soaked up by the partially cured POR near the metal. It is used for patching or coating rusty steel. It works well! I have used it on my SL on floor pans, inside trunk and to fix underbody before overcoating with rubberized undercoating.

So YES - have your daily driver rust treated (Krown or Rust Check). Most Canadians do!

[Strife]

Originally Posted by barry123400

What really is a shame is that corten steel is only about ten percent more expensive costwise. It surface rusts very slightly and then the oxidation stops. If you see a newer bridge or gaurd rail that looks brownish it is made of that material and never will continue to rust. There is no sense or need of painting it other than for esthetic reasons.

The Picasso in Chicago,the Sears Tower, and the John Hancock buildings were all made with this - I've seen them up close 20+ years after they were erected and they still look great.

[wolf_walker]

Originally Posted by Graham

So YES - have your daily driver rust treated (Krown or Rust Check). Most Canadians do!

I bought a Saab 9000 few years back that had zero rust and a receipt for rust-proofing and the tell tale holes with plugs and goo here and there.
It was a Canadian car. Looked like it worked from that example.

[wolf_walker]

Originally Posted by JiveTurkey

What part of North Carolina are you in Wolf? We could pool our labor and do both of our cars at once if you're close enough for me to tow out to you.

Bout an hour east of Raleigh, pretty good haul from anywhere in TN.

[marcedesbenz]

Originally Posted by barry123400

If the engineers and scientists thought there was really a product that could paint over rust and stop it they would use it. The resultant savings would be at least millions per year.

Government trying to save money?

[bgk202]

I like zerorust paint better than Por-15 because it is way less toxic. Supposedly they paint the underside of military humvees with zerorust.

[Swede]

How about bondo on top of POR-15. Is that possible? Have som evil surface rust on a fender......

[rstl99]

There's a number of rust-treatments in Canada such as Krown and Rust-Check that consist of drilling holes in necessary places, then inserting a wand connected to a compressor which shoots a pressurized spray of the water-displacing oil product. That way, they shoot the oil in the bottom of doors, rocker panels, inside fenders and hood/trunk lids, behind lights, as well as the whole underneath of the car (inside frame rails if a full-frame vehicle). I've had excellent success with these products for years. They are applied in the summer/fall (to allow the oil to creep into all crevices and hidden nooks and crannies). Combined with a regular carwash (including spraying water underneath to wash off the slush/salt buildup). No rust-proofing will make a salt-winter driven car last eternally, but these products add years to the life of a car, and prevent rust from starting in unseen areas until it's too late to address (inside fenders, inside door bottoms, etc.). For my money, it's the best $100 you can spend a year on a car.

POR-15 is something you paint onto the metal, after treating and neutralizing the rust.

My 82 240D came from Arizona, only drove one winter in Canada, and has been sitting in my garage every winter for the last 10 years. Nevertheless I used to get it Krown or Rust-Check treated every couple of years, so the underside and all nooks and crannies are still covered with the oil, and no rust can start anywhere.

[todds]

POR-15 would be my vote. Eastwood sells a similar product I believe. My experiences with it were generally good on my 70's alfa spider, which was a rust MAGNET. Some surfaces I prep'ed well and it worked as advertised, others I didn't do as good a job and it flaked off in big chips. This is very important with this stuff. You also need to cover the POR-15 with something to protect it after you're done. If you do that I believe it will do a good job to help keep the rust from spreading. I never had enough of it to try it on all the unrusty metal under a car.

My experience with undercoating has been bad, I usually scrape as much of the stuff off the cars I get as I can. It is usually hardened and hiding rotten metal/dirt/etc. I would implore anyone not to spray undercoating directly on to already rusty rockers/etc. I can't comment as to it's utility on a new car since I've never owned one. Personally I'm not taking the chance with my rust-free used cars. I'm talking about the rough rubbery stuff here, not Wax or oil-based products of which I have no experience. (Perhaps it worked better when it was new or for the first 10 or so years but after it's past it's prime it seems to do the opposite of what it's supposed to. And it's impossible to remove it all at this point)

Another thing I can warn heavily about due to past experience is something called "Penetrol" which is sold at hardware stores. There are a few sites on the web recommending this stuff as a budget easily obtainable alternative to Waxoyl/etc, which is hard to find in the U.S. In my experience Penetrol acted as a rust PROMOTER absorbing water and causing small surface rust dots everywhere on a formerly beautiful rust-free finish of a car I owned. It's also hard to get off, like varnish. This stuff was designed to work for thinning paint, not stopping rust on cars!

[thorsen]

Waxoyl is pretty easy to make, if you have time to wait for it. I buy gallon paint cans from the hardware store and fill them just over half-full with turpentine. Then I buy several of the wax toilet ring seals, shred them, and mix them in the turpentine. Sometimes I shred a block of paraffin wax and put that in, too.

It takes a few weeks for all the wax to fully dissolve. I make it during the summer and leave the can on the flat roof of my garage where I know it will get plenty of sun. I the fill the remainder of the can with chainsaw bar oil.

I have an Eastwood undercoat gun that sprays the liquid mixture through 3' plastic tubes with brass nozzles on the end. If you spray this into frame rails, rocker panels, or body cavities, the idea is that the turpentine will evaporate and leave the wax/oil mixture in place, which helps to prevent the formation of rust.

Some people swear by it, some people swear it's snake oil. I did this in 1993 while I was restoring my 1970 MGB and 17 years later the car does not have the typical MG rust. Was it because of the wax/oil, or was it just good luck? I don't know, but for $10 in ingredients I will take the gamble.

[JiveTurkey]

The prime disadvantage to wax / oil based undercoating or rust inhibitor that you spray into door's etc is the fact that it tends to become more liquidlike as it warms up. This isn't really a concern in winter (except near hot vehicle components like exhaust) because it's cold out. If used under the correct conditions I'm confident that a wax / oil
solution applied to bodywork is an effective anti-rust agent.

Wax and oil solutions can be a pain in the ass to remove from tough to reach areas and tend to burst gloriously into flame when welding is involved.

I'd love to give a spectacularly huge middle finger to whoever invented that rubberized undercoating. It's a sound deadening material and not really a rust inhibitor. It actually accellerates rust more than anything else and it's a mega-***** to remove.

[wolf_walker]

Undercoating is supposed to be soft-ish and take hits from rocks and such that would, in theory, scratch the paint and start rust. It is hard to get off, but if it wasn't it'd be no good at all. I use it over POR-15 on bottom/unseen surfaces, if it's something that needs protection but needs to be hard and not attract dust and such I use truck bed liner. I've also noticed spray undercoating varies a lot in quality from brand/type to brand/type.
Now POR is damn hard when properly applied, it'd likely be alright on it's own from the hammer-tests I've done here and there, but for what it costs, better safe than sorry to me.

[Ritchie]

I use POR-15 on the (interior) floor, firewall, under the cowl, in the cowl ( old fords) and in between interior and exterior panels. I use a cleaning wand hooked to the shop compressor to spray it in the tight areas like between panels and where sheet metal over laps and has a gap. Drill a holes in the rocker so I can shoot POR-15 in from differnt angles. fill holes with evercoat product. POR15 sells a filler too. Never tried it tho.
No bondo. Evercoat products or better.
There are some good industrial coatings from sherwin williams. I have several gallons. I have used it on the metal roof on my house. (I'm high class trailer trash). It has stool the test of time in that application. Have yet to test it on a parts car. I wat to try that on the bottom side of the floor pans, then under coat.

I noticed in the Mercedes service manuals that leak prevention is stronly stressed. Inspecting all window seals very carefully. These cars are very well sealed on the floor and firewall and water does get in, it is trapped. Making sure water is not getting past any seals is going to be my #1 defense once restored.

I have tested rust converters and they all failed horribly. And POR-15 works only if the surface is preped correctly. I am wicked happy with POR15 after 5 years of using it.
My rule of thumb is, "rust through" rust must be cut out and surface rust can be sanded, blasted, ground off and treated if the metal is not left too thin.