Rust prevention

[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?

[JiveTurkey]

I've heard good things about POR-15 from a little searching on here, (sanding it is a bad idea though as it breaks the barrier created by POR-15 if you're not extremely careful.)

I'm wondering the same thing though. I'm almost to the point where I'm going to try and rust proof as much as I can on Wilma. I'm tempted to POR-15 the whole underside and the floor pans on the inside, but I've never worked with it before.

Also, in one of my Bodywork books they recommend "Cavity Wax" for filling unpaintable areas. I think Eastwood company sells it. It's supposed to smell terrible, but allegedly it does a pretty good job.

[Equitas]

Isn't POR-15 a rust REMOVER?

I'm thinking more of the professional spray on systems that coat the entire underside with a light rust preventer.

[Tomguy]

POR-15 is an epoxy to cover rust. Naval Jelly is a rust remover (Muriatic Acid IIRC). Doing the whole car in POR-15 might be expensive but sure would be effective.

[barry123400]

That prq-15 is moisture cured so it is not an epoxy but a urathane I think. I have certain beliefs about rust or the oxidation of steel that have developed over the years.

Any product with a non hardening oil base will saturate the rust and block oxygen as long as the rust remains saturated with it.. Or at least the majority of it. The rust is still active but at a much reduced rate. Somehow or other a little oxygen still gets through.

We ultimatly brought a three thousand pound pressure gun to hydralically spray on a layer of grease and graphite. This worked at least as well as anything I have ever seen.

One of the reasons the thinner products are popular is it just takes a cheap gun to spray them. Not so with the grease and graphite. The thinner solutions will naturally wash off as well. On the otherhand the thicker coating of grease and graphite stiffens up from road dust and remains on pretty well.

Plus the actual material cost to do a car with grease and graphite was about 40.00 back then. The thinner products are much much cheaper in comparison. More hype than reality but still better than nothing.

Before that we dealt with a corrosion engineer. There has to be absolutly no rust present to get full protection. Otherwise the rust will still remain active to some degree. The highway bridges would not require sandblasting before painting if you think about it. 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.

There is no easy magic bullet. We never examined sacrificial anode systems. They may or may not work well but I would investigate them today. Any undercoating that seals in existing rust other than petroleum products that constantly provide a release of an oil component actually accelerate the oxidation process. We did many experiments.

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.

Cars should have been made of that stuff. Our economy instead encourages waste as the basis of our current and past economy it seems. All the energy used to produce the steel and it struggles hard to achieve its return to the natual state in nature if possible.

[JiveTurkey]

I think sacrificial anodes only work when they're in a solution, like the ones you can put in your radiator that react because they're surrounded by liquid. I don't think they would work on sheet metal thats not submerged.

[Mike D]

Be careful about using the spray on rust treatments. Some of them can cause worse damage than they prevent. I'm not saying this about all of them but here's a prime example.

The "Kiss of Death" for all old Mercedes!

Externally, the car looked great but the hidden areas...

[Petteri K]

Funny thing, I live in Finland and the only book about the topic I found in the local library was american: How To Rustproof Your Car by David Jacobs. Very good book indeed. And cheap, it seems:

http://www.biggerbooks.com/book/9780879384319

[alabbasi]

POR15 will cure and become rock hard. I think it protects against rust by adding a very strong layer of paint over the metal. They advise leaving a little rust on the metal as a tooth. There is a paintable version but I think rubberized undercoat will bond to it.

I would be weary of cavity wax insulation because it can seal up drain holes which would cause the rust to metal from the inside out. It will also make it a pain in the rear to repair again if it ever starts to rust because you're likely to set the whole car on fire if you put a welder to it.

[JiveTurkey]

People who put cavity wax in areas that have drain holes make baby jesus cry. It's supposed to be pretty good (read; cheap, easy, effective) if properly used though.

Reminds me of some of the bondo horror I've seen previously, like when there's about a four inch thick slab with nothing behind it but chicken wire...

[alabbasi]

Originally Posted by JiveTurkey

People who put cavity wax in areas that have drain holes make baby jesus cry. It's supposed to be pretty good (read; cheap, easy, effective) if properly used though.

Reminds me of some of the bondo horror I've seen previously, like when there's about a four inch thick slab with nothing behind it but chicken wire...

You should have seen what we pulled out of my 1971 250CE which I restored back in the 1996. We found chicken wire and newspaper circa 1980. Old spark plug packets lined up against the sill on the rear quarter and they even cut an old oil drain bucket in half, wedged it into the inner fender, screwed the outer fender to it and then covered it in Bondo so that it would look like an inner finder.

Practically the whole bottom 5 inches of the car had to be replaced.

[JiveTurkey]

Originally Posted by alabbasi

You should have seen what we pulled out of my 1971 250CE which I restored back in the 1996. We found chicken wire and newspaper circa 1980. Old spark plug packets lined up against the sill on the rear quarter and they even cut an old oil drain bucket in half, wedged it into the inner fender, screwed the outer fender to it and then covered it in Bondo so that it would look like an inner finder.

Practically the whole bottom 5 inches of the car had to be replaced.

Youre grinding salt in a 250CE shaped wound of mine... Haha. That had to be a major pain, but I bet it provided some damned fine lessons in bodywork.

[alabbasi]

i did'nt do the work at the time, this was when I still lived in London, had no garage and not tools. I farmed it out to an American mechanic in Hackney who came recomended through a friend. He was a black guy who routinely would call me and ***** me out about how white he looks with all the bondo dust from grinding

He definitely bit off a lot more then he should have tried taking on. It was a learning experience for both of us. He learned about bodywork and I got my first experience of scope creep.

I cut my teeth on a 350SL that I bought here which was pretty gruesome. It's buried in my weekend wrenching thread.

[JiveTurkey]

That was one of the first threads I ever started reading on here, you're an official recipient of the coveted "JiveTurkey Seal of Approval." I need to make an image people can put in their signature for people I deem worthy. Haha. Anyone have an idea how to do that?

[wolf_walker]

I did a lot of pondering on this stuff and came to a few conclusions too over the last 14 years or so of euro car fun. Don't buy rusty/wrecked cars is the first thing. That isn't real possible for a lot of us in these old Mercedes as truly rust free(if that even exists) starts to equal $$$ that isn't in the cards. Next thing I learned was the value of a spot sandblaster, high quality primer and GOOD spray undercoating, and keeping an eye on it for rock chips and such. The next thing is I really should have learned how to weld and work metal more than I can, or married the daughter of someone with a body shop.

My most recent experience, in refusing to let go of my 600K mile VW Pickup
has been with POR-15 and some creative hole patching. It was stop the rust or cut the front off and weld on a new clip, to the beat up beed it has, which wasn't really much of a solution. The POR thus far lives up to it's name. It is a ***** to prep the surface correctly, and my experimenting has shown that one really does need to if they want it to perform as advertised. I painted a few inch section of the 4x4 steel crossbar on the shop door when I did the pickup and I hit it with a ball peen hammer to illustrate it's durability to people. It's tuff, and rust does not spread where you cover it with the stuff. Also it does not come off of anything willingly, ever.
I'd be curious to try thinning it and spraying it sometime. I'd do every bottom side centimeter of every vehicle I have if I could. The thought of the brushing and cleaning and de-greasing and the application of an entire underside makes me a little weary though. Actually a lot weary.
Nothings free in life.

If I don't find the W114 a new home it will likely get quite a lot of POR'ing this summer.