why does a Z rust?

[iraqlou2007]

I was just wondering what is the cause of a rusty Z? Is it the environment the car has lived in, ie.. up north where salt is used on the roads and the costal areas where the owners drove a lot on the beach and failed to wash the underside? Or is it some sort of lack of technology in primers and paints at the time when the cars were made?

As I am starting my search for a Z I am just wondering if all I am going to find is a Z with a lot of rust.

Lou

[DCZ]

The answer is c) All of the above. Since you are in Columbia SC you will most likely find Zs that are rusty from people parking them where the kudzu grows. If you are patient you can find one with minimal rust. If you don't want to wait start looking in AZ, CA and other dryer places.

 

Have Fun!

[jnjdragracing]

My brother Jerry has a blue 240z with no rust. It has a 2x3 subframe backhalfed that someone started, has all interior as well. If you like come by and take a look at it and if you are interested he might sell it. We were going to do a tube chassis car and use this body. Just an idea, and we live in Columbia SC also.

 

John

 

I was just wondering what is the cause of a rusty Z? Is it the environment the car has lived in, ie.. up north where salt is used on the roads and the costal areas where the owners drove a lot on the beach and failed to wash the underside? Or is it some sort of lack of technology in primers and paints at the time when the cars were made?

As I am starting my search for a Z I am just wondering if all I am going to find is a Z with a lot of rust.

Lou

[RedNeckZ]

Our cars were made to last a few years at the most. They have no rust protection on them at all. If you take the fenders off, you will see that the areas not covered in tar or such from the dealer were all metal and covered in rust. We have a car here in Fayetteville, NC that is a first gen. Z. The Guy will not sell it for what it is worth. He is trying to make a small fortune from it. Thinking that someone will come along and buy it at a very high price. But if you look at it, it is rusting from the inside out. It has the normal paint bubbles (every panel) on the paint and the normal rust around the wheel wells. It even has holes in the floor boards. Who ever decides to get it, must do a lot of body work ($) to it. From what I can see, it will rust away, just sitting were it is right now (outside in the weather). I don't think anyone will be stupid enough to buy it for the price he wants. I wish I could have brought some of the Z's I had back in Colorado to NC. I had people giving them to me, just to get them out of their yards (1990's). The county came to the house and told me, I had to put insurance and plates on all of them (10). So most of them got stripped and sent to the junk yard. I had at one time ten cars listed in the world Z club. Rust is our greatest enemy. It never sleeps and can only be removed with a lot of work. The car was made very cheaply and it rusts a lot. To save them, we must take them apart and start from the inside and work to the outside. That is why most people take a few years and rebuild them after stripping them (check out other sites on the internet). Hope this answers some of your questions. Before you buy a Z make sure to do a complete inspection of it and be honest with yourself, decide if you want to spend however much to fix it back into shape. It will be your time and money that will make it happen. Good Luck, hope you find a rust free body out there.

[MrFancypants]

Or is it some sort of lack of technology in primers and paints at the time when the cars were made?

 

This is mainly the reason. Technology has changed a lot in 30 years. Back in the 70's they didnt give 10+ year corrosion warranties like all the manufacturers do nowadays. They just painted bare metal and hoped for the best. Today you get full chem dip unibodies and much higher quality paint.

 

Your best bet is to look for a Southwest Z.

 

 

 

- Greg -

[CalifaThugz]

I have a 77 280z, I am willing to sell for 300$ I live in Apple Valley California, there is a problem with it though, I don't have papers for it and it hasn't ran since the year 88. We did rebuild the engine like 3 years ago, but I just haven't had time to really get it running. Missing injector screws and all that. I have the front end to the car just that the driver side fender is gone. I was going to try and get it running before my summer vacation ended and then go back to school. I'm a freshmen , but then I finally had all the parts to work on my 240sx after working for so dang long. I also have a 280zx I am willing to sell an 81' N/A it runs perfect just that my brother 2 years back took all the interior out. I'll sell that one for 400$. Giving back to my hybrid community for all the knowledge that they sent to me about cars. As some may remember I sold a 280z couple months back for cheap. Running and all just had an electrical problem for 300$ When the muffler itself costed me 150$ =] Have fun PM me if interested.

[Rhnmsf]

im interested in the 280z........any pics?

[bjhines]

I think MOST of the rust problem comes from the fact that the entire car is stamped out of 26g sheet metal.

 

There are some design aspects that also contribut to the problem.

The primer they used was designed to "weld through". The individual sheet stampings were primed BEFORE the chassis was spot welded together. They literally welded right through the surface primer. The original protective primer is very thin and only does a minimal job of sealing the metal. There are a lot of stampings that overlap one another and trap moisture. The overlapping areas also make it impossible to PAINT in between the overlapping surfaces. To make matters even worse they used seam sealer applied with a brush(or fingers). The seam sealer rarely sealed the seams properly. Excess sealer also trapped water in places it needed to drain.

 

The floorboards rust very badly because the tar noise insulation pads were applied BEFORE PAINTING. The only thing under the tar pads is pre-assembly primer-sealer. The tar pads were never applied in such a way that water could not get under the insulation. The factory never used seam sealer around the edges of the tar pads to ensure that they were water tight. The combination of the poorly applied tar pads and the fact that water could ealisy get under them meant that MANY of the S-30 Z cars rusted within the first YEAR they were on the road.

 

Modern design and manufacturing has eliminated most of these problems. Many cars are dipped in paint and sealer to ensure that every nook and cranny is filled with PAINT.

 

The cars were designed in an era before they had completely figured out how to make a thin guage unibody car that would resist moisture and rust.

[SHO-Z]

At the time that they were made Japan was importing a lot of scrap metal and using it to produce steel. The first Honda cars the fenders would rust thru in less that a year or so in some places. Their steel industry was not up to producing the high quality steel that they do today.

 

There was also a rumor that some of the problems was that they were using a lot of scrap steel from the shipping industry and had a lot of salt imbedded in the steel.

[bjhines]

No offence SHO-Z. This is just a pet peeve of mine.

 

The poor quality materials theory is a no go. There are obvious engineering faults with the rust-prone early unibodies. The poor quality steel idea was an ignorant attempt aimed at ignorant people to slander the import car makers in general.

 

There may very well have been some aspects of the Japanese steel supply that was not up to spec with the steel that American manufacturers used. Those faults have a lot more to do with the performance of the metal during the industrial processes involved with stamping and forming the metal.

 

In fact the "low quality steel" the Japaneese used was more than enough to make American cars look like rolling shitpiles by the middle of the 1970s... and everthereafter.

[Pop N Wood]

The poor quality materials theory is a no go.

 

I have to disagree with that one. Maybe true for a Z, but it certainly wasn't true for Japanese cars in general. There have been cases where auto sheet metal would rust from the inside out. That was true for domestic as well as foreign. I think there were a few law suits from it too.

 

Remember back in the 50's-60's Japan's manufacturing abilities were about as mature as China’s are now. They did use a lot of low quality, recycled materials and did produce a lot of low quality stuff.

 

Kind of scary to think where China will be in 20 or 30 years.

 

Also keep in mind cars didn’t use to cost as much as they do today. Car manufactures thought of them as throw away items, and since all car manufactures were doing it basically the same way, why dump a bunch of money in corrosion protection.

[SHO-Z]

One last input on this one. I was a pipe welder during this time. Fittings made in Japan would weld like S**T modt of the time. The steel was soft and had impurities in it. You could see them float out in the puddle. On one project we had to cut out a lot of fittings made in Japan because of all of the inclusions in the fittings that they found in the x-rays.

 

The early 70s Japan was converting from low quality products to where they are today.

 

Korean fittings in the 80s where the same way and ones from India were a complete joke.

[iraqlou2007]

Thanks for all the input, it's funny but I never thought of it as 30 yr old cars.....damn time flies when your having fun.

 

Lou

[bjhines]

I just watched the Boneyard show on the history channel.

 

One interesting fact that came up is that 75% of the metal used in cars manufactured in the USA... 75% is SCRAP METAL!!!!!!! 3/4 of hte steel is scrap right here in the good old USA.

 

It is facts like these that make me feel like the argument that poor quality steel is NOT the problem with rusty old Japanese cars.

[Tony D]

Steel is what they call the most recycled metal...

 

it's lack of prevention techniques, coupled with thin metal which speeds perforation, plain and simple.

 

GM stopped buying USX product in the 80's because Roger Smith found the studies showed the Japanese Steel was in every way comparable, but at close to 60% of the cost. There was a well-publicized meeting where Roger told the head of USX at the time "GM wants to use American Steel, but for the cost, and the quality, we will have to make some hard decisions to keep our shareholders happy in regards to supplier costs!"

 

In other words: Make better steel, or make it cheaper, but one way or the other we aren't buying it just because we've always bought from you!

 

American cars to the mid 70's used Cross-Sectional Thickness as the primary corrosion 'prevention' method. Just make the sheetmetal thicker, and it takes longer to rust perforate. Some MBA and Accountant conspired a Cost-Benefit-Analysis and foudn it was cheaper to use steel than to make it thinner (with those costs of tearing in complex dies, etc) and corrosion treat it.

 

As galvanic treatments decreased in cost, and deposition technology advanced---as well as CAFE got stricter and vehicles were pressed to be lighter to meet CAFE, the metals got thinner.

 

in the 50's, hell you just put thick sheetmetal on and it took 5 years to rust through.

 

Itwasn't until the 80's that US MAnufacturer's changed that philosophy.

 

The Z's Philosophy was of lightest possible weight, hence the thin sheetmetal. It was rumored eraly protptypes had issues with metal buckling because it was SO thin, and as a result the gauge thickness was INCREASED!

 

Different Engineering Goals, and Philosophies.

[MrFancypants]

You definitely can tell that the Z body panels are very thick gauge compared to current cars. Just think of how light the S30 could be with modern unibody technology!

 

As for the scrap metal market, it has been insane for a few years now, all because of our good friends the Chinese. It's interesting to see us selling all of our scrap and shipping it overseas to be reprocessed and shipped back to us. But it all boils down to supply and demand and scrap metal supply is extremely low compared to the demand. It's even gotten to the point where old blast furnaces are being fired up again because the cheaper electric furnaces arent so cheap given the high cost of scrap steel.

 

 

 

- Greg -

[bjhines]

I have an observation. Not with this forum as much as others I visit.

 

A lot of people can post hundreds of words explaining good reasons why Z cars rust. This kind of post is intended to give people a good clue on why they rust and where to look... maybe this is of no real use...

 

But a part of the conversation will always come down to "low quality materials"... China?.. I do not have any opinion to give on political issues. Everyone makes good and bad commodities in ever country in every era.

 

It is like saying the S-30 cars are made of ♥♥♥♥ and there is nothing you can do to understand or fix them.

 

The fact is that Nissan put together an industrial engineering masterpiece from it's conception to delivery and for History. It would be unwise to assume they used poor quality materials at all. Everything was engineered to do exactly what it is supposed to do and nothing more.

[CalifaThugz]

I'll get pictures soon I just need to get batteries for my camera.

[Pop N Wood]

The fact is that Nissan put together an industrial engineering masterpiece from it's conception to delivery and for History. It would be unwise to assume they used poor quality materials at all. Everything was engineered to do exactly what it is supposed to do and nothing more.

 

You don't know much about the realities of engineering consumer items.

 

It's all about making trades. Using what's available and cost effective. I will bet money there wasn't an engineer on the original Z car design team that didn't have a list of things they would have changed if they had the power to do it.

 

Manufacturing capabilities and processes do mature as a country becomes more industrialized. That has nothing to do with race or politics. Just a fact.

[bjhines]

Pop-N-Wood,

I think you interpreted that differently than I had intended in writing it. Your assumptions about my understanding of engineering practices are unfounded.

 

I laid out numerous reasons WHY the S-30s rust in post #8. There I explained several shortcommings of the early unibody design that makes it prone to rust. I also gave several examples of how technology and engineering practice have progressed over time to provide much better rust protection in modern cars.

 

My peeve is with those who try to lay the rust blame on poor materials. It is ridiculous to assume that poor quality materials are to blame. Anyone who assumes this... needs to pull their head out of the sand. It is sad that people still fall for this NASCAR redneck propoganda. The Japanese car industry put the rest of the WORLD to shame in this early period.