Melting Aluminum in "Open" Fires, Like in the World Trade Center on 9/11

PepeLapiu

New Member
Hey guys. First post here. Well, the NIST claims that the fires were hot enough to melt aluminum. And the NIST also claims that what we see dripping from the tower could be molten aluminum.

My big problem with this is that it's simply impossible. Sure, the fires probably burned above the melting point of aluminum. But that is only part of the puzzle. For reasons I can explain later, you just can't melt aluminum into a liquid form in fire. You might melt it, but never to a liquid form.

You don't have to believe me. You can just try it yourself. Get a piece of aluminum and see if you can melt it into anything that can resemble a liquid.

Use a candle if you want. Or a wood fireplace. Or you could even buy a propane torch at Home Depot for less than 20$. The simple fast and the matter is that it's not possible to melt aluminum to a liquid form in an open flame fire.

So either NIST is outright lying about this. Or they are more clueless than a first year welder flunky. Which one do you think applies?
 

Trailblazer

Moderator
Staff member
My big problem with this is that it's simply impossible. Sure, the fires probably burned above the melting point of aluminum. But that is only part of the puzzle. For reasons I can explain later, you just can't melt aluminum into a liquid form in fire. You might melt it, but never to a liquid form.

Hello and welcome - please consider posting over in the new members thread.

Regarding melting aluminium in a fire being impossible, how do you explain photos of aluminium car wheels that have melted into liquid in fires?

upload_2017-12-28_11-7-45.png

Or people discussing casting aluminium using open fires?

I have successfully melted aluminum repeatedly using only an open fire contained in a large barrel or sand pit. I don't recommend soda cans or foil. I have had best results with window frames, old siding, and small engine blocks (weed eaters, lawnmowers) as you can tell from my choice of metal sources I tend to salvage things. As a side note all the glass that falls out of the old frames makes some neat blobs in the ashes when they cool down.
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http://www.instructables.com/answers/Campfire-powered-foundry/
 

PepeLapiu

New Member
Your video actually pretty much confirms what I was saying. What you have to understand is that it's not an open air fire depicted in the video. It's effectively a forced air furnace which provides more heat than an open air fire. As we both know, fire needs a lot of oxygen to burn. But you should understand that aluminum oxidizes extremely rapidly. In fact aluminum oxidizes so fast that you likely have never seen or touched real aluminum in your whole life.What you can see an touch is actually a very thin film of aluminum oxide that forms on top of the aluminum as soon as it's exposed to air. But the interesting thing is that unlike steel rust, the aluminum oxide layer acts as a sealant over the aluminum, effectively guarding it against further oxidation.
But this oxidation process gets even more accelerated when you heat up the aluminum.

If you build a forced air furnace as was done in the video and you use a crusible to prevent your aluminum from oxidizing too much, you may melt aluminum in fire. But it's not an open flame fire. And those conditions would be virtually impossible to happen by mere hazard in an office fire.

Furthermore the fire in your video, being in a forced air furnace, was able to burn with plenty of oxygen supply, effectively, with very little heat lost, and very little smoke. This is a very sharp contrast with the smoky smoldering fires observed on 9/11. And even NIST has said that the fires of 9/11 were burning inefficiently in an oxygen depleted environment. This the yellow/orange flames and the thick dark suety smoke.

If you want to melt aluminum in fire, you have to separate the aluminum from the flames as was done in the video with the use of a crucible. And you have to pump more air in the fashion of a forced air furnace while trying as best as possible to contain the heat within the furnace.

But if you just light as fire, and throw in as piece of aluminum, you will never melt it that way. Or at least not into a liquid form.

Furthermore, the guy in the video likely did it on a very calm day with very little wind. Because if any significant amount of air had been allowed to circulate into his crucible, he would have ended up with nothing more than a pile of grey slag - aluminum oxide.
 

Oystein

Senior Member
The melting point of pure Al is 660 °C. Most of the Al we might expect in the fires of WTC2 would have been alloys. Alloying tends to lower the melting point. For example, the 7075 Al alloy, with about 5% Zn and 3% Mg plus a few other metals in smaller amounts, around 90% Al, which is widely used in aerospace applications including airframes, has a melting point in the range 477-635 °C, according to this source. The common 6061 allow, which has lower percentages of other metals (Mg ~1%, Si around 0.6%...), still has a somewhat depressed melting point in the range 582-652 °C (source).

@PepeLapiu You would have to explain, or source, why an office fire could not heat stuff, Al, to 600 °C, or why it wouldn't melt once heated to that temperature! What else happens to Al that's heated to above its melting point in an open fire?


You say: "You might melt it, but never to a liquid form."
But the very DEFINITION of the word "to melt" is "to make liquid by heating above melting point". I will excuse myself putting slightly more trust in the qualifications and judgement of the NIST PhDs whom I know by name and title than in an anonymous internet poster who says you can melt without making liquid - which is an oxymoron.


Edited to add:
Given that the two previous posters already debunked your claim by showing you Aluminium made liquid in open hydrocarbon fires, I am curious: Where did you learn that doing so is "impossible"? Can you source this? Can you specifically name the individual or organization from whom you learned this? I am guessing your source is some web resource and the content created by someone who can be fairly identified as a 9/11 Truther. Am I guessing correctly?
 

Mick West

Administrator
Staff member
it's not possible to melt aluminum to a liquid form in an open flame fire.

This tiny little fire can melt chunks of aluminum:
20171228-091607-qw5l7.jpg
Video: Melt Aluminum in a Campfire 2:04
Result:
20171228-091715-b9ljl.jpg


Firefighters discuss the melting of aluminum in structure fires
https://forums.firehouse.com/forum/...orum/61041-melted-aluminum-at-structure-fires

If you go to many mobile home fires (I do), you'll find that in a really well involved fire the aluminum siding will melt and run. I've seen it numerous times.
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We attended a training initiative in Northern BC in 2000, where we burned an entire community at the Alcan Aluminum smelter powerplant in Kemano, BC.

The company produced aluminum, so they supported the industry in any way they can. Many of the houses were built extensively with aluminum, inlcuding siding, rooves, doors and windows.

When those houses were finally allowed to burn into the basement after a several evolutions, you should have heard the pops and splashes from the melting aluminum warping and boiling in the basement. It was quite perplexing on the first couple until we realized what it was.
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Patty, the chance of encountering aluminum in a liquid state are real,real, slim. It cools pretty quick, But, I have had a few bits of melted aluminum on my Coat and Helmet, from fire venting from an upstairs window and melting the rain gutter as we forced the door, 2 stories below.
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Suggesting the WTC fires could not is just ridiculous. These were huge fires, tens of thousands of times larger than the campfire.
 
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Trailspotter

Senior Member.
Exposed to the air, metal aluminium is covered by a thin film of aluminium oxide that melts at a much higher temperature. If you try to melt thin pieces of aluminium in open fire, the molten metal tends to remain inside the "bag" formed by its oxide film. We used to do this at school chemistry lessons with aluminium wire, which was widely available in our country at the time. At the same lessons using the same burner, we melt bulkier pieces of aluminium (with less surface to volume ratio) in a crucible to obtain liquid metal for casting.
 
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Trailblazer

Moderator
Staff member
If you build a forced air furnace as was done in the video and you use a crusible to prevent your aluminum from oxidizing too much, you may melt aluminum in fire. But it's not an open flame fire. And those conditions would be virtually impossible to happen by mere hazard in an office fire.
And what about forest fires? Are they not "open-flame fires"? A quick Google image search produces numerous pictures of aluminium car wheels melted into liquid by forest fires.

upload_2017-12-28_18-37-52.png


And you can hardly call the WTC fires just "an office fire". I'm pretty sure a fire roaring through a 100+ storey skyscraper has more "forced-air" effect than a few logs in a hole in the ground with a small fan blowing on it.
 
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Mick West

Administrator
Staff member
Or you could even buy a propane torch at Home Depot for less than 20$. The simple fast and the matter is that it's not possible to melt aluminum to a liquid form in an open flame fire.

Here's someone who melted an aluminum can with a propane torch in an open environment.
20171228-104457-lb0wq.jpg
Video: Melting aluminium cans with a propane torch

Of course, there's a problem with rapid oxidation when directly applying the flame. In this example, thinner aluminum sheeting almost seems to evaporate away.
20171228-105346-c6fci.jpg
Video: Aluminum Sheet melted with Blow Torch

But just because sometimes you get rapid oxidation does not mean you will always get it, as shown above.
 

LardyL

Member
"you just can't melt aluminum into a liquid form in fire. You might melt it, but never to a liquid form." Really?

A couple of additional points from the theory/practical side that haven't been mentioned or fully explored -

1. Eutectics are regularly formed in fires in structures and these will reduce the melting point of metals or alloys, so using a pure metal to simulate the behaviour of an alloy or even a pure metal in a real fire situation is not a fair "test".

2. The heat transfer properties of the material will affect how easily it is heated by a flame/other heat source, for example, if you are trying to ignite a curtain or drape with focused sunlight (from a lens or curved mirror for example) you will find (perhaps counter-intuitively) that the more thermally dense (thicker) material will more often than not ignite ahead of the lighter weight fabric, due to the insulating properties of the denser material allowing for heat to be retained. This means that trying to get thin slivers of aluminium to form droplets/liquid pools under test conditions will be harder than heating up more substantial aluminium objects (window frames for example) and seeing the aluminium sag, melt and flow away from it in streams of liquid to form drops and pools. This is what happens in real fire situations.

3. Having personally attended well over a thousand fire scenes/tests/examinations of evidence there are very few that I have evaluated for origin and cause where there has not been some trace of aluminium (as an alloy, most likely) present after the fire either in the form of re-solidified pools, drip patterns or small spheres of the metal material in some part of the debris. The only explanation for this finding is that the aluminium does melt, pool and run during structure fires. The only structure fires I can recall not seeing any aluminium in this state were those that were extremely localised fires or those where no aluminium was likely to be present - pallet/waste fires, small fires on the edges of sinks/baths, deep seated fires/smoulders in cellulosic materials, small localised fires following explosions, etc
 

LardyL

Member
And furthermore having a fully involved structure fire where, as you say, the atmosphere is somewhat vitiated, with lower concentrations of oxygen present, then metals and alloys behave somewhat differently than in the test conditions that you opine on. Surface oxidation of liquid aluminum and reduction of any surface aluminium (or complex) oxides will occur in real fires in ways that are not simulated by your "ad hoc" tests.

Furthermore, your idea that the fires on 9/11 were somehow "smouldering" and not free burning/flaming, due to the observation that they were "smoky" is a false assumption as anyone who investigates or fights fires professionally will confirm. Those fires would have been reliant on/limited by availability of air for combustion as there was plenty of fuel in the offices and having such a large window area then there would be substantial quantities of air for combustion available to rush in through those openings. From outside those areas would appear less damaged/involved in fire, as openings for ventilation into compartment fires almost invariably are, but the real damage and real fire development would occur within or where the products of combustion would be venting (also usually window openings or the like). This explains how survivors of the initial impact were able to remain close to some window openings during the horrific incident, whilst fires were raging within the structure and how the same ventilation effects would cause melting of aluminium joinery, etc that could flow and run out of the building in other areas.

"But if you just light as fire, and throw in as piece of aluminum, you will never melt it that way. Or at least not into a liquid form."

Consider this debunked from theory and decades of "real world" fire experience.

Or just ask my youngest son who has asked me to bring back "interesting" items from fires and has handled the very re-solidified pooled aluminium remains that you claim cannot be formed in a normal structure fire.......complete with sharp edges/points, rounded corners and the other characteristics of this ubiquitous material as it melts, pools and runs in fires within/beside buildings, around vehicles, involving plant, in mines, on roadsides, in fields, down drains and in pretty much any other setting where fires occur.
 

Mick West

Administrator
Staff member
Or just ask my youngest son who has asked me to bring back "interesting" items from fires and has handled the very re-solidified pooled aluminium remains that you claim cannot be formed in a normal structure fire.......complete with sharp edges/points, rounded corners and the other characteristics of this ubiquitous material as it melts, pools and runs in fires within/beside buildings, around vehicles, involving plant, in mines, on roadsides, in fields, down drains and in pretty much any other setting where fires occur.

Here's an example of aluminum in a small house fire:
https://www.eboss.co.nz/ebossnow/steel-framing-strong-performer-in-fire
IMG-0762.jpg
Metabunk 2018-01-23 17-49-22.jpg
 

LardyL

Member
Thanks Mick, showing an example from my current backyard of NZ, in fact my son is coming back from summer camp to Papatoetoe tomorrow, where the NZ F&E personnel were stationed who attended that fire.
 

LardyL

Member
In fact come to think of it I investigated that very fire on Nuneaton Drive, Flat Bush,and it stuck in my mind as I used to live in Nuneaton in the UK! The SMS Report is not an actual fire investigation report and there would have been a more detailed report. Here is a photo of the area I was interested in - where the fire started in the kitchen.....Steel framing did a decent job and there was a lot of aluminium flow onto the window sills as you can see. Now that's weird, eh?low res_DSC_4417.jpg low res_DSC_4424.jpg low res_DSC_4443.jpg low res_DSC_4461.jpg
 
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LardyL

Member
It was quite a serious house fire, but it was enclosed as such and there was plenty of aluminium on the threshold of the external doors, at the bottom of the windows - eg this large window at the rear of the property:DSC_4426_crop.jpg
 

Mick West

Administrator
Staff member
In fact come to think of it I investigated that very fire on Nuneaton Drive, Flat Bush,and it stuck in my mind as I used to live in Nuneaton in the UK! The SMS Report is not an actual fire investigation report and there would have been a more detailed report. Here is a photo of the area I was interested in - where the fire started in the kitchen.....Steel framing did a decent job and there was a lot of aluminium flow onto the window sills as you can see. Now that's weird, eh?
Coincidence! I just did a google image search for something like "fire scene investigation aluminum"

Trying to repeat that I found this interesting snippit:
https://archive.org/stream/Fire_Arson_Investigation_Manual#page/n37/mode/2up

Alloying of metals

Another reaction that occurs during a fire is the formation of eutectic alloys.
Eutectic is the lowest melting point of an alloy or solution of two or more
substances that is obtainable by varying the percentage of the components. This
takes place when the melting temperature of one material is reached during the
fire, and this melting material comes in contact with another metal. The resulting
mixture (alloy) will melt at a temperature lower than the melting temperature of
the higher melting temperature metal, and in many cases lower than either metal.
In fire situations eutectic alloying occurs when molten aluminum or zinc comes in
contact with steel or copper

Copper wiring, tubing, and piping quite often are affected by alloying. Aluminum
can mix with the copper to form an alloy which ranges in color from yellow to
silvery. The surface of the spot of aluminum might appear gray in color, while the
surface near the aluminum-copper interface may be fairly dark. The copper wire
will be very brittle. Zinc also will alloy with copper, forming a yellowing brass.

Alloying with steel does not occur readily in most fires; however, if aluminum or
zinc are heated for an extended time with a steel object then alloying may result in
pits or holes.


Alloying may be confirmed by metallurgical analysis, and the alloy may be
identified. One theory is that if metals with high melting temperatures are found
melted, this is an indication of incendiarism. Scientific fact shows that if these
metals are melted due to alloying, such melting, is not an indication that
accelerants or unusually high temperatures were present during the fire.
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LardyL

Member
Yeah, the formation of eutectics (which is the more technical term for the process ;-) ) is often a confounding issue when you are doing scene work, particularly when looking for electrical arcing/erosion/distress or when you are looking for indicators of the temperatures that were present during the fire at various points at the scene.

This is because aluminium from other sources (in the old days from the outer sheath of "pyro" cable, or MIMS, mineral insulated metal sheath cable - such as that used in fire alarm wiring or in high hazard areas was a common issue in commercial fires) can cause the copper conductors to melt at a lower temperature and give "false positives" for the electrical damage that occurs naturally to energised circuits when they experience a fire and the "causative" effects of electrical failures. It can also interfere with the "arc mapping" that we fire investigators use to help identify point of origin (and hence cause) of a fire.

I'd be a little careful using sources such as the one you quote as regards some of the fire science issues (although they are broadly correct regarding the cause of "alloying") as some of the older documents were aimed at the very broad church of fire investigation "professionals" in the US and similar jurisdictions, where the standards of investigation have historically (with some very well-known, serious miscarriages of justice with innocent people executed for fires that were not even proven to be deliberate in cause) been "patchy". Hate to be a snooty British forensic scientist but some of that type of educational material still carries many of the "old wives tales" of "indicators of incendivism" and the like.

The best general "noddy's guide" to this field is NFPA 921 which can be found on the NFPA website and if you register with NFPA then you can see the current document, which although rather basic in some areas, is kept up to date on most issues and is considered in many circles to be the "standard" for fire/explosion investigations:

https://catalog.nfpa.org/NFPA-921-Guide-for-Fire-and-Explosion-Investigations-P1386.aspx

My most thumbed book on the subject is the Ignition Handbook, which I have a well worn copy and is a great source of information and sources for the fire investigator, at $200 US in pdf form I might just download it to put it on my phone, lugging the thing around to meetings and trials is bad for the back. An absolutely immense work in the field - it was considered so good that I bought 4 copies in hardback from Barnes & Noble for my former UK colleagues, in about 2004, a true magnum opus:

https://www.doctorfire.com/Ignition_book_CD.html
 
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LardyL

Member
Oops - Wikipedia reveals that what I wrote was a little misleading, MIMS is not the copper sheathed mineral cable - that is termed MICC and was the actual "pyro"; MIMS being that type of cable with a sheath made of something other than copper. The cable we used to come across that cause most problems for us back in the day was sheathed in aluminium alloy, hence how it would interfere with the state of the copper conductors inside it. You see far less of this nowadays as the heat resisting cables are now sheathed in plastics not metal.
Early in the morning here still!
 
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