5 hours ago, Assurancetourix said:

That's also what I think; ten years ago the metal parts were more cast iron than steel so not prone to rust.

Steel rusts just as easily as cast iron, that's one reason why steel car bodies are painted.

5 hours ago, AAArdvark said:

Never drive in the rain

You think that will stop discs rusting?

Nothing to worry about. BUT they should be painted at those spots. Something you need to see been done. Make yourself

11 hours ago, Just Weird said:

Steel rusts just as easily as cast iron, that's one reason why steel car bodies are painted.

Steel in general is less prone to rust but it still rusts. By how much depends on the steel.

Pure iron is almost nonexistent these days and has been for decades.

post #95. hmmmm … refer to post 2, 3 , 4, and 5. ???? bs accumulates after that (not ALL though) end

Edited September 11, 20196 yr by jastheace

Absolutely you could end up burning the rubber flexible brake line.

50 years ... and U post this ? 55555

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21 minutes ago, jastheace said:

post #95. hmmmm … refer to post 2, 3 , 4, and 5. ???? bs accumulates after that (not ALL though) end

Discs aren't iron, they are steel.

Steel is an iron alloy, pure iron has virtually no uses in modern times. .... Except of course for making steel.

Edited September 11, 20196 yr by wilcopops

Interesting to note that the OP's vehicle is fitted with rather "spidery" alloy rims, so it's probably the first time he's been able to take a good look at the discs of his own vehicle. 

48 minutes ago, wilcopops said:

Discs aren't iron, they are steel.

Steel is an iron alloy, pure iron has virtually no uses in modern times. .... Except of course for making steel.

why pick on my post ? irrelevant quote, where's the ref when you need him ?????

55 minutes ago, jastheace said:

why pick on my post ? irrelevant quote, where's the ref when you need him ?????

Because in the posts you refer to there is a statement that says discs are iron and you cite them as no b/s.

3 hours ago, wilcopops said:

Discs aren't iron, they are steel.

Steel is an iron alloy, pure iron has virtually no uses in modern times. .... Except of course for making steel.

Most daily drivers have gray iron rotors, which is basically cast iron. But, there are other types, depending on usage, including steel...

 

https://carfromjapan.com/article/car-maintenance/what-are-brake-rotors-made-of/

 

6 hours ago, wilcopops said:

Steel in general is less prone to rust but it still rusts.

I know, hence my post.

7 hours ago, jastheace said:

post #95. hmmmm … refer to post 2, 3 , 4, and 5. ???? bs accumulates after that (not ALL though) end

This can come in handy.

You can waste your time putting all the high temperature paint you want on your discs but in the situation of repeated heavy braking it won't stand up to this. ????

PS.

It's not red paint.

Your best solution to overcome this problem is treat the rust with a rust converter chemical,can brush on or purchase small spray can,the rust will turn into a gunmetal blue type colour,after application rust will not form again for ages,have used it myself many times.

19 hours ago, MartiniMan said:

As mentioned here check the VINs as you may been sold a cut and shut - look for weld marks around the door frames that seem odd

the Vin number i have here does not start with a number but with MP.

I tried it and in 5 of 6 websites had no result (invalid number).

According to autodna.com this is the vin of a Lexus Model IS II (2005-2012).

 

Like i said in my 1st post it's not that i don't understand there can be some rust in the brakes. What surprised me it was to see the part completely covered of it.

That seemed strange to me after only 2 days. 

 

20 hours ago, MartiniMan said:

Just checked the brakes on new isuzu are anodised and painted with anti rust so although you were told the truth its not what u have in reality

anodised and painted with anti rust? mine are clearly not lol

4 hours ago, overherebc said:

This can come in handy.

gonna need a container load of it with some of the bs going around at the moment, this topic included.

On 9/11/2019 at 1:10 AM, gk10002000 said:

But frankly what concerns me is the white chalk mark on one of those pictures.  Why is it marked?  Is it possible the brakes or disk were swapped out? 

Probably a manufacturers 'witness mark'. They're used during assembly to let the next phase of assembly know that a certain procedure has been completed. 

6 hours ago, Moonlover said:

Probably a manufacturers 'witness mark'. They're used during assembly to let the next phase of assembly know that a certain procedure has been completed. 

understood.  good point and certainly a possibility

19 hours ago, wilcopops said:

Steel in general is less prone to rust but it still rusts. By how much depends on the steel.

Pure iron is almost nonexistent these days and has been for decades.

Iron and cast iron has better corrosion resistance than steel (except stainless or high-alloy). 

6 hours ago, Damrongsak said:

Iron and cast iron has better corrosion resistance than steel (except stainless or high-alloy). 

yep. indeed. steel has workability properties, iron has its own properties. iron is processed into steel to meet criteria. its primary constituent is iron. steel is not mined, it is not a natural product. iron is manipulated into many products, processed and alloyed, easily researched if you have to, known by many without research. iron, steel is easily identified by visual means. carbon content, alloys with nickle, less so, but why people comment without knowledge, when wiki is just 4 keys away. high iron content products are evident 300 years later, steel without corrosion treatment tries to revert to its natural form within a few years. ever owned a ford car? in the 80's an owner would gain welding skills out of necessity. 

1 hour ago, jastheace said:

yep. indeed. steel has workability properties, iron has its own properties. iron is processed into steel to meet criteria. its primary constituent is iron. steel is not mined, it is not a natural product. iron is manipulated into many products, processed and alloyed, easily researched if you have to, known by many without research. iron, steel is easily identified by visual means. carbon content, alloys with nickle, less so, but why people comment without knowledge, when wiki is just 4 keys away. high iron content products are evident 300 years later, steel without corrosion treatment tries to revert to its natural form within a few years. ever owned a ford car? in the 80's an owner would gain welding skills out of necessity. 

Some of the Toyota Tacoma pickup trucks in the USA weren't any better than Fords.  There was a recall where they would buy the truck back or put on an entirely new frame free of charge.  Ouch.  We had one with a fist-sized hole in the frame under the passenger seat. Others would rust further up front and the suspension would fall off.

 

As a blacksmithing enthusiast and general nerd, I am familiar with metals.  I encouraged my son to become a machinist/welder and learned a lot in the process. There are hundreds if not thousands of recipes for "steel" alloys, not many for cast iron. Cast iron does sometimes have nickel or other elements for specific purposes. There's a book called "Woldman's Engineering Alloys" - about 1,800 pages.  Not just iron/steel, but still...

 

Weird part is that relatively pure iron has a rather high melting point.  Steel is intermediate and cast iron is lower, due to the high carbon inclusion.  "Wrought" iron was called so because it was relatively pure iron with slag, so it would be pulled from the furnace in a gummy mass and pounded into shape. It didn't melt at the temperature they could attain easily.

 

I have a couple scraps of real wrought iron that I found in dumps or in the area of an old homestead here in the USA.  Bits of property marker stakes or reinforcing straps for a long-gone wooden wagon.  Very durable.

Edited September 13, 20196 yr by Damrongsak

Those do not look like new discs to me.  Looking at the last photo, It looks like there is already a wear ridge on the outer edge.  Also the diagonal scratches look as if someone has been trying to break the glaze to maybe try to cure judder or squealing.  I would get them independently examined.

On 9/12/2019 at 8:25 AM, transam said:

Most daily drivers have gray iron rotors, which is basically cast iron. But, there are other types, depending on usage, including steel...

 

https://carfromjapan.com/article/car-maintenance/what-are-brake-rotors-made-of/

 

 

On 9/12/2019 at 12:03 PM, Oztruckie said:

Your best solution to overcome this problem is treat the rust with a rust converter chemical,can brush on or purchase small spray can,the rust will turn into a gunmetal blue type colour,after application rust will not form again for ages,have used it myself many times.

Gray iron is iron with carbon.. So technicially its steel

1 hour ago, wilcopops said:

 

Gray iron is iron with carbon.. So technicially its steel

If you say so...

My 2015 Trailblazer with 60,000 km looks like this - not a fraction of the rust the OP shows.

The brake disks back then were zinc plated.......they don't do that in 2019, anymore?

28 minutes ago, mistral53 said:

My 2015 Trailblazer with 60,000 km looks like this - not a fraction of the rust the OP shows.

The brake disks back then were zinc plated.......they don't do that in 2019, anymore?

All cast irons/metals are not equal regarding water causing a rust film...

36 minutes ago, transam said:

All cast irons/metals are not equal regarding water causing a rust film...

yes - that is correct, it's also not mentioned in my post as the reason for my car having zinc plated rotors, and the OP brake disks are obviously does not. This is not about materials, it is about rust inhibition that obviously in the case of my Trailblazer has done an excellent job in prevention surface rust.

 

7 minutes ago, mistral53 said:

yes - that is correct, it's also not mentioned in my post as the reason for my car having zinc plated rotors, and the OP brake disks are obviously does not. This is not about materials, it is about rust inhibition that obviously in the case of my Trailblazer has done an excellent job in prevention surface rust.

 

Your rotors are zinc plated by Chevrolet or something you did ?