ace37

I've got a TT coming in January and we have real winter here. We also have salt and other garbage on the roads. I'd like to drive the 911 more or less every day, but I plan to keep the car a long time and want to minimize any corrosion damage. I'm sure others have this sentiment and may be interested to see where this thread goes. Porsche does a better job than most from the factory but supplementing their good efforts can only help the car.

For corrosion, in the aircraft world we apply corrosion preventative compounds to areas where corrosion is anticipated to inhibit rust damage. (One well-regarded source describing CPCs is this group: http://corrosion-doctors.org/Inhibitors/CPCs.htm) We can get similar products that can be readily applied to cars; TC-11 and CorrosionX are examples of well known products. CorrosionX seems to be better marketed and distributed. I can't help but think TC-11 is all done by an engineer. When applied to panels they are reported to spread to cover surfaces and even climb vertically. They typically are tacky and attract dust. TC-11 has a nineties website with some good info about application and usage:
http://www.tc-11.biz/autos_motorcycles
http://www.tc-11.biz/autos_motorcycles/6545-2

These coatings are typically viewed as a sacrificial layer that get used up over time. They corrode so your car doesn't, and over time the coating becomes inert and no longer helps, so it needs periodic reapplication. I'm thinking in our moderate winters here a single annual application in the fall would be a good way to go.

I was thinking to get TC-11 or CorrosionX/CXHD, get the car up on a lift, take the wheels off when putting on the winter tires, and follow the TC-11 instructions and make sure to cover at least everything they recommend. I'll also do the door hinges, and quite frankly I might just put a light coat on basically anything I can see from under the car that looks susceptible to corrosion. I'd like a better process, but that's where it will start. If I get any taken I'll put up pictures.

Since this isn't a topic I found a lot of information on rennlist on, I thought I would start a thread and describe my plan. Looking into this makes me think we should do this for our SUV too. And yes, I could just drive another sacrificial car all winter, but that's part of what pushed me towards getting a 4wd 911. I don't want to buy a sports car I have to leave parked all winter - I'll park it on the bad days but want to drive it most of the time.

I'd love to hear from others who have considered this or have done something similar.

ace37

I found a bit of independent test data from a marine forum summarizing a test apparently done by a magazine called Powerboat Reports:
http://www.thehulltruth.com/sportfis...or-sprays.html

They did a rather harsh test: "Each of the test products was applied to two mild steel strips—one to be suspended in salt water and the other to be sprayed with fresh water." This is probably much more harsh than any reasonable automotive application.

They find a few components that do a decent job, but they may not be as well suited to automotive usage. One example is wax CPCs that perform well may not spread to coat a panel like TC-11 and CX are reported to do, so if you can't access a full panel to spray it, areas would remain uncoated and unprotected. Another consideration is if some of the CPCs use harsh solvents that would damage plastics and other car parts.

So the best performers on that test might not be great for our automotive application, but the results are still interesting.

991carreradriver

Intersting, I used CorrosionX on two airplanes that I owned. Very good product but I am not certain that it will do much for our P-Cars. On airplanes, we sprayed the areas that were hidden from the direct elements. In most cases that was accomplished by removing inspection panels or after the interior was removed for refurbishment. Virtually the entire interior skin of an airplane could be accessed and sprayed. Most older metal airframes were not corrosion proofed when they manufactured. Our cars are submerged in a corrosion proofing process. Not sure there is much to be gained here.

Icebreaker

Another product that gets good reviews, and one that I use is "Krown Rust Control". It covers surfaces and creeps without washing away. I cannot get Corrosion-X in Canada. "Fluid Film" is also used with some success, but again, it is a wax-like product and does not creep... but sticks and stays flexible. "Rust Check", another popular product in this salt infested winter wonderland, will creep into crevices, but has been debated to contain more thinner than rust-proofing properties. "Krown" seems to be the product of choice here in Halifax where we have six months of freeze-thaw temperatures, constant road salt, salt spray from the ocean and acidic fog (that fog has just about wiped out all the fish in our many, many lakes). It's a tough place to keep a car (and fish!). Thank you for starting this thread.

Needsdecaf

worf928

If you're going to keep your TT a long time, then don't drive it during Salt Season.

That written, I use CorrosionX, on my winter DD (which is not my 991TT.)

It is practically impossible to cover all of the bits that will corrode when subjected to salt, heat, and water unless you disassemble the car.

The body and panels are not the issue. Those are protected already. What isn't protected are: nuts, bolts, heat shields, hose ends, hard lines, any bare or painted metal that is steel. Basically: anything metal that isn't unibody or body panel or obviously aluminum.

Prior to the 90s these bits were zinc chromate plated. Prior to the mid-00s they were at least zinc plated. Now they don't seem to be plated at all.

CamsPorsche

After watching the Discovery Channel show "How its Made" I was surprised to hear that the 911 goes through 7 or more cathodic dips where the car is fully submerged, rolled and dried in the rust prevention dip.

Driven991

I have not done this my P Car but have considered it. I do not plan to drive the 911 when the sand and salt hit the road.

However I have owned a couple of saltwater fishing boats in the past and sprayed CRC Corrosion block on anything I did not want to corrode like fuse blocks/ground blocks/electrical ring connectors, etc. It does work. Don't get it on anything you don't want coated because it is an ugly brown/orange and does not come off easily and it is sticky and attracts dust/dirt.

On my pickup truck that I use in the salt and snow I spray the undercarriage with regular CRC or WD-40 from a squeeze spray bottle twice a year. These items are not a waxy coat but offer some level of protection. If you go this route make sure you wear eye protection and clothes you don't care about or a white painters suit. This stuff blows everywhere even on a windless day so don't do it near another car you don't want it on.

I decided on the regular CRC/WD-40 route after talking to a gentleman from Canada who said his father did this on his pickup truck and the underside looked very good after 10 years of Canadian winters. Regular applications seem to be the key.

Good thing you have a lift because sliding under a 4wd truck is a pain in the butt...did I mention safety glasses and a hat or head covering?

Our department of transportation had something on their website about spraying the undersurface of the car with a baking soda solution and then rising it off as a means of neutralizing the salt. I also take a rainbow type lawn sprayer and park it under the truck and let it run 5 or 10 minutes then move it to the next section of the truck and runs some more.

sctanton52

I think a lot of the products discussed above would work fine, but they do need to be reapplied on a fairly regular basis to keep on working. And having a good lift would be very useful so as to get the product to all required areas. As noted above, wear proper safety gear, especially your eyes. Whenever I am doing aerosols I also wear a proper mask, suited for the product being sprayed. The links provided some good advice, IMO.

jimbo1111

Correct. Porsche usually doesn't have a problem with rust. Galvanized body's since 1983 or so. I've owned a few 1986 951's and have driven them through snow and all sorts of rock salt winters and only saw a tiny bit of rust on the passenger front fender on one car. That was only surface rust as the metal was still perfect behind the surface rust. That was 30+ years of driving year round.

ace37

Good to hear some real world experience with these cars over the years. I'm pleased to hear they fare so well over the long term in regions with much more road salting than my own.

I wasn't so worried about the body or frame due to the lengths Porsche goes to, but I was more concenred that the exhaust system, some suspension components, and exposed nuts, bolts, and other hardware might be at risk or prone to corrosion. While that's all replaceable, I was thinking when swapping tires over in the fall/winter, an hour or two devoted to corrosion mitigation might significantly extend the life of the underbody metal parts. It doesn't seem to be a big enough problem to sweat a lot more than that over.

I really like the idea of a rainbow type lawn sprayer. I was trying to think of a simple way to wash the underbody in the event of an unexpected salt bath, and that's about as easy as it can get. We're finishing our basement next year, and I was thinking to have 240V and some water run out to the garage. At that point your idea would be very simple to implement.

991carreradriver

I use a touch-less car wash in the winter. They typically have high pressure under carriage water jets. My car's under carrige looks like it just came from the factory. They only problem is that they blast away my brake sensor bypass heat tape.