FEMA says melted steel at WTC 7

I can ease everyone's mind from my experiences in residential and commercial construction.

No drywall corroded any steel at any point in time in the history of using drywall on steel construction.

No aluminum used in construction of steel buildings ever corroded any steel. Very little aluminum is ever used in commercial steel construction, because it bends, creases, and crimps too easily, and is not a good conductor of HVAC air heat flow on long distance, particularly in commercial buildings. They cannot use it as connectors close to any flames from heat sources. That is fact not fancy.

If they were going to use aluminum piping (square, rectanglar or round), they woud use it in ventilation systems (fresh air in, stale air out) and smoke exhausts in buildings containing heavy smoking of cigarettes, cigars, and pipes.

Originally posted by OrionStars
If they were going to use aluminum piping (square, rectanglar or round), they woud use it in ventilation systems (fresh air in, stale air out) and smoke exhausts in buildings containing heavy smoking of cigarettes, cigars, and pipes.

Wouldn't they actually use lead coated copper? That's what I usually specify for sheet metal.

The only things I know of that are aluminum are aluminum mullions and window framing. And also aluminum clading.

In my experience, the metal used for sheet metal flashings and equipment is lead coated copper. Of course, I could be wrong. Notice I said "in my experience".

reply to post by Griff


Not on HVAC duct for heating and cooling. Galvanized steel is used in residential and commercial. It has been for years including when the WTC complex was built.

reply to post by Griff


Then sometimes uses thin gauge sheets of stainless steel, but it can become cost prohibitive.

reply to post by Griff


You can check your home dryer venting. They will not use aluminum at the connector to the dryer (heat issue), but your venting can be alumuinum, including aluminum foil that springs in and out.

Thanks for the info. Obviously, I don't work with HVAC equipment much other than to flash sheet metal to the equipment when we are rehabilitating a roof.

Sometimes stainless steel is used but when we need to solder the sheet metal, you can't use stainless steel (it won't "stick" to the galvanizing layer).

reply to post by Griff


reply to post by Griff


You are welcome.

I did not note any aluminum flashing around the exterior of the windows where the sun could hit it. It causes too much glare from the sun off buildings. All flashing I have around my windows is vinyl to match the color of the window frames.

They were atypical windows in the towers. The fit between all those 3 story spaces between each of the tube-in-tube supports of the exterior perimeter walls. They were 18" wide in every slot. If there was any aluminum flashing on the inside, which I seriously doubt, it would have been blown off when the buildings were dropping.

The perimeter wall frames were not primary support for the towers. They were primary supports for lateral load stabilized by the center core supports. The center core supports were primary load for the buildings. Then there was all that skeletal steel framing inside the perimeter interior core support as well. No aluminum cladding on any of it.

When I mentioned stainless steel, I was referring to primary HVAC ductwork in commercial buildings only. It can be used for more durability. It is also cost prohibitive as well.

Originally posted by Griff
Can you agree that this corrosion of the steel could possibly be a major find? To the construction industry worldwide? Without having to go into a conspiracy? Since the potential would be there for every building to do this?

100% agreed
There's a lot of potential good that can come from such disasters as history has shown.

reply to post by OrionStars



I didn't mean aluminum flashing on windows. The windows would only be framed with aluminum and then there is the aluminum clading of the steel columns. There actually was, to my knowledge, a lot of aluminum on those buildings.

WTC 7 is a different story. From pictures that I've seen, it looks like it was clad in granite. But, the window frames would still be aluminum.

I did jump the gun though before when I didn't mention stainless steel sheet metal. I must have had a brain and forgot about SS. Probably because I haven't had to specify it yet myself. I recently started to write specs for work, so I'll run into it soon enough.

Originally posted by Pilgrum
There's a lot of potential good that can come from such disasters as history has shown.

Would you also agree that this potential good can only be achieved through the proper study?

Or can the good be achieved by saying "it coulda/shoulda/woulda" without verifying that it can?

Originally posted by Griff
Would you also agree that this potential good can only be achieved through the proper study?

As long as we don't exclude a 'what if' type approach from the investigative toolbox.

This probably isn't the best forum for a balanced look at the possibilities with what I see as a heavy bias in favour of a CD causing the devastation but it's giving me plenty of food for thought, being a conspiracy forum. A lot of those 'smoking guns', to me at least, actually aren't but I do look at them all.

From a structural engineering viewpoint, 'what if' there's the slightest chance the failures didn't involve any devices apart from planes, fuel, falling rubble and fires?
That possibility, however small, deserves the greatest amount of attention but if we adopt the mindset of a CD, it leads to the *likely* false sense that the buildings would have remained secure unless explosives were used.

The molten steel controversy is interesting but is it evidence of the steel melting at the time of collapse or simply a testimony to the energy of the post-collapse fires?

Considering the time elapsed since 9/11 we may never have the full story.

Originally posted by Pilgrum
Considering the time elapsed since 9/11 we may never have the full story.

100% agreement.

Basically, I feel the "investigation" was a farse as far as a scientific investigation goes. Which leads me to believe that there are other reasons why "they" did not want it investigated.

What those reasons are, I don't pretend to know. But, it is something.

reply to post by Griff


I have stated before there has never been any adverse reaction of aluminum to steel in any commercial buildings before or after. The frames on each window would not be a material that would contradict the steel holding it.

Labs, such as UL, are the labs that test what materials react to other material, plus, other chemical catalytic agents in building materials. They test it under every adverse condition. UL was the lab testing the steel and other materials being used in the WTC. Electrical wiring, etc.

It has to be tested, particularly in commercial buildings, under any and all adverse conditions. The steel in the WTC buildings was rated higher, for all conditions, than what had previously been used in any other commercial buildings. That was one of the few true remarks made by NIST, when they analyzed the steel remains they were allowed, by FEMA, to take.

I seriously doubt the window frames of the twin towers were aluminum. While it may work in residential, it would not work in buildings getting hit consistently with 100 mph winds or more. The aluminum would get too stressed and start popping out of the slots with all that swaying back and forth and pounding by the wind. Aluminum is a very soft metal. Even aluminum alloy is not always feasible to use in commercial. Durability and stability will be some primary issues in commericial building.

Any aluminum flashing surrounding the slots, in which to set the frames, would have the same problem. If they were going to use anything to frame and set windows, it would be something like light weight stainless steel to endure all that beating from windshear factor or fire, inclusive of consideration of any chemical catalytic reaction between metals. Something not so easily compromised to tear loose from the surrounding slots holding the windows.

NIST sets all standards on construction materials tested by labs set up to test all adverse reactions between materials. Then NIST tests them also, or are supposed to, in order validate independent labs are correct in their findings. Peer review of testing concerning public safety before disaster strikes.

The only aluminum cladding, on any steel used in construction of the WTC buildings, was that used on the tube-in-a-tube steel facade of the building for corrosion prevention and eye appeal. That is all the aluminum cladding placed on any steel used to construct the WTC buildings. Framing is not cladding. The facade was attached to the outside of the builidng. along with the steel sections of perimeter primary load support wall frames, which also held the floor trusses, on the perimeter side, plus, the windows.

Originally posted by OrionStars
I have stated before there has never been any adverse reaction of aluminum to steel in any commercial buildings before or after. The frames on each window would not be a material that would contradict the steel holding it.

You are correct. The aluminum is the less noble metal and therefore would be the sacrificial anode.

Galvanic series (nobler higher)
The following is the galvanic series for stagnant (that is, low oxygen content) seawater. The order may change in different environments.

Graphite
Palladium
Platinum
Gold
Silver
Titanium
Stainless steel (316 passive)
Stainless Steel (304 passive)
Silicon bronze
Stainless Steel (316 active)
Monel 400
Phosphor bronze
Admiralty brass
Cupronickel
Molybdenum
Red brass
Brass plating
Yellow brass
Naval brass 464
Uranium 8% Mo
Niobium 1% Zr
Tungsten
Stainless Steel (304 active)
Tantalum
Chromium plating
Nickel (passive)
Copper
Nickel (active)
Cast iron
Steel
Lead
Tin
Indium
Aluminum
Uranium (pure)
Cadmium
Beryllium
Zinc plating (see galvanization)
Magnesium

en.wikipedia.org...

en.wikipedia.org...

Labs, such as UL, are the labs that test what materials react to other material, plus, other chemical catalytic agents in building materials. They test it under every adverse condition. UL was the lab testing the steel and other materials being used in the WTC. Electrical wiring, etc.

Which goes back to my point that they would already know how gypsum reacts with steel (if at all).

I seriously doubt the window frames of the twin towers were aluminum. While it may work in residential, it would not work in buildings getting hit consistently with 100 mph winds or more. The aluminum would get too stressed and start popping out of the slots with all that swaying back and forth and pounding by the wind. Aluminum is a very soft metal. Even aluminum alloy is not always feasible to use in commercial. Durability and stability will be some primary issues in commericial building.

You might be right about the twins, but every other commercial building I've inspected, specified, designed, etc. has had aluminum window framing.

Here's a manufacturer to get you started.

Kawneer is a leading manufacturer of architectural aluminum building products and systems for the commercial construction industry. Providing single-source responsibility, our comprehensive product portfolio includes entrances, framing systems, windows and curtain wall systems. Kawneer products are used on a myriad of applications such as; high- mid- and low-rise buildings, stadiums and sports facilities.

products.construction.com...

NIST sets all standards on construction materials tested by labs set up to test all adverse reactions between materials. Then NIST tests them also, or are supposed to, in order validate independent labs are correct in their findings. Peer review of testing concerning public safety before disaster strikes.

Exactly why the "gypsum was able to melt and corrode the steel" argument is null and void.

The only aluminum cladding, on any steel used in construction of the WTC buildings, was that used on the tube-in-a-tube steel facade of the building for corrosion prevention and eye appeal. That is all the aluminum cladding placed on any steel used to construct the WTC buildings.

I know this. That is what cladding in the construction industry means.

Building construction

In building construction, cladding may refer to the application of one material over another to provide a weather-proof layer intended to control the infiltration of weather elements. Cladding does not necessarily have to provide a water-proof condition but is instead a control element. This control element may only serve to safely direct water or wind in order to control run-off and prevent infiltration into the building structure. Cladding applied to windows is often referred to as window capping and is a very specialized field.

en.wikipedia.org...

Framing is not cladding.

I know this and never said otherwise.

The facade was attached to the outside of the builidng. along with the steel sections of perimeter primary load support wall frames, which also held the floor trusses, on the perimeter side, plus, the windows.

Yes, the facade. Composed of aluminum cladding.

On a side note: I've noticed you like to argue with everyone. Even those who agree with you. Just an observation. Please don't take it the wrong way. I mean no disrespect to you by saying that.

[edit on 1/15/2008 by Griff]

reply to post by Griff


Thank you again.

As I stated, such labs as UL certify commerical construction materials all the time, including any drywall reaction to metal on which it is hung. What works in residential, is not always suitable for commercial.

Unless there is a listing of all material components used in any of the WTC complex buildings, we will never know what materials were used everywhere in those buildings. We can know quite a number of all of them, but probably not all. Unless there is a complete listing somewhere, and someone will part with it, as they did with the blueprints of the twin towers.

NIST will not do that concerning the WTC complex. They never had much material to test after the buildings all came down. They were not allowed to take it. Unless someone can get their hands on the original construction designs, which includes a complete listing of all the materials used with specs, etc., we will never know. It all becomes mere speculation. Only mine is being done based on experience in both residential and commercial construction, inclusive of materials normally used.

Unique designs always require unique material specifications. What is normally done ceases being normally done with material specifications. Construction principles are always the same. Material specs are not.

reply to post by Griff


I did not realize we were arguing. I was merely explaining where aluminum cladding was and was not and why. I was disspelling misconceptions based on experience. That was my only intent.

Originally posted by OrionStars
Unique designs always require unique material specifications. What is normally done ceases being normally done with material specifications. Construction principles are always the same. Material specs are not.

I can agree with you 100%. Especially about not having the structural documentation. I'd love to do some structural calcs myself, but, alas, I can't without knowing the construction of the building. That get's us to "how could Dr. Greening, Ryan Mackey et al, have the answers either?". Because they aren't privy to the same information that is needed by us. So, it is mere speculation on their part also. This goes for both sides of the fence.

reply to post by OrionStars


No worries. I wasn't arguing either. Cheers.

reply to post by Griff


We can certainly agree on that. Without knowns, it is impossible to calculate anything with any accuracy as you just correctly pointed out.

Just an observation from looking at pics of the aluminium cladding in the street in relation to corrosion:

The cladding overlapping joints appear to have been weatherproofed with a silastic type material and these generally have a service lifetime of around 20 years before becoming brittle and cracking creating the possibility of water getting under the cladding by 2001. The aluminium was covering up the 'SFRM' fire proofing sprayed on the exterior and sides of the columns and SFRM, being a concrete type mix, would be strongly alkaline when wet and being porous would hold moisture well.

All that would be needed for strong galvanic activity is for the damp SFRM to be in contact with the underside of the aluminium and directly connected to the steel at other location like where it was fastened on the inside of the columns. The alkaline solution sitting on the steel would create corrosion by itself, particularly at welded joints.

That would create a nightmare fixup job because all the windows were mounted on that aluminium cladding (per NIST construction info). It wouldn't melt steel but it would certainly affect it over the years.


[edit on 15/1/2008 by Pilgrum]