Sciencemadness Discussion Board - Thermite for melting steel

Thermite for melting steel

chief - 5-4-2010 at 03:53

Suppose I have a 15mm steel-rod and want to melt through it (just for sports, or because maybe it's too hard for any tool, and acid would take too much time ...)

==> Probably the choice would be thermite ...

So far I did one try, with 50 g of the stuff from sparking-candles:
==> It was placed around the rod, gave lot's of intense light, burned down within 5 seconds ...
==> but the rod didn't even glow ...

==========

==> What sort of thermite would work best ?
==> How much addition of Ba(NO3)2 for extra-oxygen makes any sense ?
==> Does it have to be some sort of "thermite lance" or could it suffice to place the material loosely around the rod ?

etc. etc.

How could the 15 mm steel-rod be completely melted through ?

[Edited on 5-4-2010 by chief]

chief - 5-4-2010 at 04:05

One of my ideas might be to use some plaster-based thermite ...
==> Would that work even when the plaster would be cast, therefore containing water ?
==> As a mixture of eg. MnO2-based thermite with plaster-based thermite, maybe cured at 200 Cels which would remove a lot of the water but not completely destroy the mechanical stability ... ?

JohnWW - 5-4-2010 at 04:35

Thermite? There has been found evidence that built-in thermite bombs were used to demolish the WTO Towers and Building 7 in New York on 9/11/2001, by melting through the steel support columns in them. Pools of molten and then solidified steel found in the basements could not have resulted from ordinary fires fueled by the kerosene jet fuel of the planes, which could not have burned hot enough to melt structural mild or low-alloy steel, and certainly not in the only hour or two before the buildings collapsed, - and collapsed so neatly on their own footprints, with visual and audible evidence of explosions on each successive level downwards.

hissingnoise - 5-4-2010 at 04:41

The obvious choice would be an oxyacetylene flame!
The material from sparklers contains little Al but a pile of Al/perchlorate mix might do the job.
Ordinary thermite would melt your steel but it would also produce its own molten iron.
BTW, John, you don't really believe that 'theory', do you?

grndpndr - 5-4-2010 at 08:12

Quote: Originally posted by JohnWW

Thermite? There has been found evidence that built-in thermite bombs were used to demolish the WTO Towers and Building 7 in New York on 9/11/2001, by melting through the steel support columns in them. Pools of molten and then solidified steel found in the basements could not have resulted from ordinary fires fueled by the kerosene jet fuel of the planes, which could not have burned hot enough to melt structural mild or low-alloy steel, and certainly not in the only hour or two before the buildings collapsed, - and collapsed so neatly on their own footprints, with visual and audible evidence of explosions on each successive level downwards.

Absolutely incredible!

Im sure the mysterious paint on "nano thermite" would do the
trick.Of course the unseen floor by floor enginered charges that caused the pancake collapse were essentil as well.No it was not the natural air compression of collapsing floors causing the "faux paux explosions".Simply diabolical!

The WiZard is In - 5-4-2010 at 08:19

Ok lets put aside science for the moment. Your experts claim that a well organized group of say 50 people working 24-hours a day in an occupied office building, (of course no one saw them as they had bought cloaks of invisibility on eBay.) Broke down hundreds of walls to expose the buildings columns. After breaking down all those walls they then used sledge hammers to break away the cement block walls around each column. Then after braking
down walls and cement blocks - they scraped off the asbestos insulation sprayed on the steel as fireproofing. (WTC 1 and Part of WTC 2, as the use of asbestos for such uses was banned during the construction of WTC 2. I don't know what it was replaced with.)
Now that all the walls were breach, cement blocks cracked, asbestos scraped. Without anyone noticing, they then brought ton and tons of thermite into the building. Followed by the attachment
to the steel column "some sort" of magic container allowing termite to cut vertical column horizontality.

The work being completed with no one complaining that their offices are now a complete shambles, some method is employed to ignite the termite soon after the planes impact the building. And with terrific planning, the thermite is placed on the same floors that are impacted.

Well if you believe this, there is a bridge not far from the WTC site that I am willing to sell you really cheap.

There is one point not discussed about which I am willing to say that I was wrong. I watched them build the WTC from the digging of the "bathtub", installation of the slurry wall, to the erecting of the steel above ground level. I remember looking the steel supports at basement level and said to myself .... GAD! I have watched a lot of NYC buildings go, but I have never seen such thick steel beam. This building will last forever........ Sad.

gregxy - 5-4-2010 at 08:23

The Mythbusters tried to cut a car in half using thermite.
It did not work very well. Its difficult to keep the hot
zone close to where you want it. Demolishing a building
by melting its supports with thermite is rediculous.

Metal cutting tools "burn" the metal as much as melt it.
So you would want an oxidizer that can oxidize iron and
use an excess of the oxidizer. MnO2 seems like a good
choice. You could also try KN03, but the nitrogen generated
may tend to blow the reactants away from the steel rod.

Plasma cutters are a the best way to cut metals. Or
look up a "thermal lance". All these tools use a steam
of oxygen to burn the metal.

quicksilver - 5-4-2010 at 08:36

In the late 1960's there was a product sold in welding supply stores that was a thermite "bag" for fixing cracks in backhoe blades, etc in the field. This was (as I remember it) bags of 4.4, 8.8 lbs and larger with a special little tube type igniter. They took on a weldment of about 2.5" (for the SMALL one). I have seen themite used commercially and there is NO WAY that thermite could be used to crash a building: it would require hundreds of lbs for a single "I"-beam laying flat.
The supports in a commercial demolition need to be pre-cut (BIG torch cuts) and topple charges need to be positioned over the course of weeks as the formula for dropping a building changes as measurements are taken. NO ONE is going to drag torches into a large populated commercial building in a clandestine fashion. What's more those cut angles and charge positions CHANGE prior to the event.
But the use of thermite is actually a "no starter" for any type of cutting. It does not work in that way. It does NOT burn through an engine block & all sorts of rubbish that popular fiction sets it out to do. It burns and WILL fuse a crack but you need a shit-load! There IS a military thermite "grenade" but it is meant to ruin a computer and things of that nature. It could melt a automobile hood easily & it would RUIN the hoses, distributor cap and other important items in such a scenario.....but I KNOW for a fact it does NOT melt through the car toward China. Thermite levels to even get INTO the engine block would need to be easily 10 lbs or more.

The WiZard is In - 5-4-2010 at 08:36

I would use my Plasma torch.

Thermit(e) [Thermite is a registered trade mark] Is not
very good at cutting, it is however, commonly used in welding.
On the Science (?) channel the episode on building the St Lou.
baseball stadium they show it being used to weld railroad track.

For more info I recommend —

Welding Handbook Sixth Edition Section Three Part B Welding, Cutting And Related Processes
American Welding Society Latest edition.

Oxy-Acetylene Welding and Cutting: Electric, Forge and Thermit Welding Together with Related Methods and Materials Used in Metal Working And The Oxygen Process for Removal of Carbon
HAROLD P. MANLY
Chief Engineer The American Bureau of Engineering Chicago
Frederick J. Drake Co. Publishers 1916

Calcium sulphate (plaster of paris) would certainly generate enough heat, it can be cast into whatever shape you desire. It is
important it be oven dried to remove moisture so it doesn't explode from steam pressure. It is hard to ignite, an acetylene/air torch works. Or use one of the standard thermit igniter comps.

"During World War I, binders such as sodium silicate and sulphur or celluloid were added in order to reduce segregation of the termite[®] after loading ; however,these techniques were only partially successful. Thermite® has not been used since World War I for incendiary applications. While the heat released by a
thermite mixture is sufficient to heat the products of the reaction to around 3000oC, the incendiary action is confined to a relatively small area. In order to improve the incendiary effectiveness, several other incendiary composition including several modified thermite[®] compositions, have been tried without success. The composition of some of the incendiary mixtures tried are given in Table 5-9."

"Therm-8" added 0.90 % sulphur and 0.30% castor oil with a large % of barium nitrate.

"Therm 64-c" Added 2% sulphur and an even larger % of barium nitrate.

"Calcium Sulfate Thermite® Consisted of Aluminum and calcium sulphate w/1.0% sulphur and 0.3% castor oil.

AMCP 706-185
Engineering Design Handbook
Military Pyrotechnic Series
Part One
Theory and Application
April 1967

The CaSO4/Al thermit w/ 3 pts "iron oxide" is off the wall. As camouflage, ferric oxide is sometimes added. Details are in one of the low albedo books.

--------
The WiZard's Welding Service —
WE STAND BEHIND OUR WORK.
But never under it.

The WiZard is In - 5-4-2010 at 16:00

The American Welding Society's "Welding Handbook" 7th ed Volume 3 says:

Themit(e) welding a 24 x 36" section with a 2 5/8" gap requires .... 3 125 pounds of themit!!

------
Chemical demo goes out of control

An explosion occurred during a chemical demonstration at the University of Illinois,
Urbana-Champaign, earlier this month. The widely used demonstration of the thermite
reaction-which involves the reaction of iron oxide and powdered aluminum to form iron
and aluminum oxide-was part of the university's annual Engineering Open House for
local high school and grade school students. There were 200 to 300 people in the
chemistry lecture hall at the time of the explosion. Four teachers and 23 students were
taken to the hospital, where they were treated and released. The injured suffered first-
and second-degree burns and minor cuts. Chemistry professor Steven S. Zumdahl,
who was conducting the demonstration, says it had just been run successfully using
sand as a receptacle for the molten iron. But when the sand was replaced with water,
something went wrong. Jiri Jonas, head of the department of chemical sciences, says a
committee, including university and local safety experts, has been appointed not only to
determine what went wrong with the thermite demonstration, but also to review all
safety issues surrounding the open house.

March 12, 1990 C&EN23

-------
Föredrag vid PYROTEKNIKDAGEN [Pyrotechnic Day] 1971
Stockholm den 10 maj 1971
Aluminium Powders For Explosives And Pyrotechnics
Gustaf Windqvist

Aluminium powder in explosives
As can be seen from the name of the article, I have tried to deal only with
aluminum powder for explosives.

Mainly I have tried to do this because I do not have any first-hand experience of
explosives and in the audience there is a number of chemists from the explosives
industry, who could contribute to the discussion of the use of metal powders in
explosives and pyrotechnics

As a final vignette I might be permitted to show a rather funny picture of an
explosion in water, which I had the improbable luck to take with a common camera
more than 20 years ago.

At the company we were playing with certain thermite charges, who were
supposed to have a certain effect in undercooked water streams. One of these charges
contained atomized Aluminium powder A 80 and copper oxide in an equivalent mixture.
If such a charge was lighted by a generator-gas match in air, it burned quickly and if it
was lighted by No 8 detonator it detonated and you got a beautiful copper-cloud in the
air. We thought that if it was used under water, with a generator-gas match, it would
burn quickly, but to our surprise, if not a pure detonation, we got a very fast deflagration
I succeeded in taking this photograph of the water-bubble, which emerged just before it
burst You can see a tendency of bursting on the top, and the white dots are
white-glowing charge. See figure 3.

[Two possibilities come to mind.
The temperature of the reaction may have been sufficient to dissociate water into
hydrogen and oxygen, which then explosively recombined. Or this may be a classic if poorly understood “liquid metal water explosion.” ]

Aluminium and water can be detonated.

Dr. Goldschmidt describes his invention - themite

The WiZard is In - 5-4-2010 at 16:11

Da FAQ's sez i can post an attachment. So here be it.

Remember this was scanned by me and you know what that means!

The master speaks :—

ALUMINIUM AS A HEATING AND REDUCING AGENT.
BY DR. HANS GOLDSCHMIDT AND CLAUDE VAUTIN.
The Journal of the Society of Chemical Industry (6)17:543-545
June 30, 1898

Attachment: Thermit Journal.txt (39kB)
This file has been downloaded 1220 times

watson.fawkes - 6-4-2010 at 07:07

Quote: Originally posted by JohnWW

I take it this is a reference to the Steven Jones paper. I read it when it first came out, and it is without a doubt the single worst scientific paper I've ever read. Just awful, really. It's no wonder he was suspended and eventually lost his academic job. I don't have the patience to get into this topic in any deep way, but a couple of comments are in order. The molten material seen in the rubble was far more likely some form of slag, requiring a much lower temperature to remain liquid. As for the explosive sounds, it's instructive to look up the speed of sound in steel, as the main columns make quite a good sound conductor, and there would be a point of constructive interference near the bottom of these columns as the front end of an impact wave, broadened by dispersion, interferes with the back end. Finally, I've read a plausible, albeit untested, mechanism for initiating aluminum combustion in the fuselage by SO2 released from gypsum drywall.

bquirky - 6-4-2010 at 19:03

Hello, Im going to bust out my favorite thing and say you could use electrolysis to cut the bar. Make it an anode soak it with an electrolyte (posibly heled in a sponge)

The mythbusters did this successfully in a myth called "Salsa Escape" using salsa and the transformer from a small radio.

It would have the advantage of being silent not altering the tempering of the steel bar (if that mattered)
and being much much faster than passive acid etching (allthough it whould probobly still take longer than other methods

chief - 7-4-2010 at 04:11

Quote: Originally posted by bquirky

Hello, Im going to bust out my favorite thing and say you could use electrolysis to cut the bar. Make it an anode soak it with an electrolyte (posibly heled in a sponge)

The mythbusters did this successfully in a myth called "Salsa Escape" using salsa and the transformer from a small radio.

It would have the advantage of being silent not altering the tempering of the steel bar (if that mattered)
and being much much faster than passive acid etching (allthough it whould probobly still take longer than other methods

Yes, electrolysis is my second favorite idea ... ; I once opened a lock with it ... (for which there was no key anymore), it took 1/2 hour to go through the 5 mm ...

I also experimented upon electrolytically cutting more massive steel ...
==> but the NaCl-elecyrolyte I used became poor in Cl, therby alcalic and passivated the metal ...

================

Also the goal would be to accomplish the destruction of the bar within maybe 20 or 30 seconds, not minutes ...

[Edited on 7-4-2010 by chief]

hissingnoise - 7-4-2010 at 05:03

Quote:

How could the 15 mm steel-rod be completely melted through ?

Only a cutting torch would go through it in 20-30 seconds. . .

quicksilver - 7-4-2010 at 07:43

Someone would sneak standard cutting torchs & associated bottles into a secure building....ohh so easy. There are mostly 2 feet long and the bottles are about 5 feet (for the O needed). Total: about 270lbs. Oh...& the need would be about 30 of those units.
Realistically, this could not be done in a clandestine fashion. The level of sparks, slag, and associated heat & smoke would be similar to a Bong-party in a sheriff's office.

The large ship-yard torches are much larger than most suspect and use up quite a bit of fuel. Any electrical operated cutting tools would not be portable and run on 480Vac. The weight of an "I" bean is quite astounding for even a small section. The more any of the "conspiracy" issues are actually looked into w/ an open mind, the more they are a serious "NO-GO"....

911-issues.jpg - 158kB

[Edited on 7-4-2010 by quicksilver]

The WiZard is In - 7-4-2010 at 08:02

Quote: Originally posted by hissingnoise

Quote:

How could the 15 mm steel-rod be completely melted through ?

Only a cutting torch would go through it in 20-30 seconds. . .

----------
It would go through a lot quicker that that! 2 seconds or less.

The good old days.

The Oxy-Acetylene Handbook
Union Carbide 3rd ed. 1976

Some Early Exploits
Although oxygen cutting was actually demonstrated at the Seattle World's Fair, shortly after the century opened, commercially-useful torches were not available for several years. In 1907, Eugene Bournonville, one of the outstanding figures in the development of the oxy-acetylene processes in the U.S., showed the U.S. Navy Yard in Brooklyn that 14-inch portholes in armor plate 2-3 in. thick could be cut in 12 minutes.

Before that demonstration, the portholes were being chipped out, after huge kerosene torches had preheated the steel. It had taken two torch operators and five chippers 10 days to cut one porthole. Later that year, American-made cutting torches were used on the demolition of the old Grand Central Station in N.Y. City, at one-twentieth the cost that older methods would have entailed. The next year, three men with cutting torches cut out the four 70-ton structural steel shields which had been used in construction of the H & M railroad tunnels under the Hudson River, a job which would otherwise have required 20 workmen.

In 1910, a 9000-ft. pipeline built to bring water down to hydroelectric generators from a natural reservoir
in Colorado began to leak so badly, only months after it had been placed in service, that some kind of repair was essential. Pipe diameter was about four feet, with walls more than an inch thick at the lower end, where the internal pressure was 825 psi. Butt joints in the pipe had been held together by heavy steel straps riveted to the pipe on both the inside and outside. A half-million dollar investment was in jeopardy. Working through the dead of winter, welders repaired 200 joints successfully, using acetylene generated on the spot from 18 tons of calcium carbide and fed to torches through lines as long as 500 feet, and oxygen made from 23 tons of potassium perchlorate in two stationary plants then compressed into cylinders.

&c., &c.

The WiZard is In - 7-4-2010 at 08:38

Quote: Originally posted by chief

Suppose I have a 15mm steel-rod and want to melt through it (just for sports, or because maybe it's too hard for any tool, and acid would take too much time ...)

==> Probably the choice would be thermite ...

---------
Eugene Song and Gene V Tracy
Enhanced Incendiary Grenade
Proceedings of the Twenty-seventh International Pyrotechnics Seminar. July 2000
Pp. 393-411

"The most basic thermate grenade [see ref for composition] is that of the AN-M14 TH3 ... first produced in 1952." The AN weighs 2 pounds. "It is both heavy and bulky for the solider to carry."

"FM 23-30, Grenades and Pyrotechnic Signals, states that an AN-M14 is capable of penetrating 1/2-inch thick stel plate. However, recent testing.... has shown that the current AN-M14 TH3 grenade is only capable of penetrating 1/8-inch thick steel plate."

"A device with greater penetration capabilities is the "Thermite Penetrator Device, U.S. Pat. No. 4,216,721.....

"While the Frankfort Arsenal device has merit, and a 1.5 pound charge the thermite could penetrate 1-inch steel plate..."

The new 25% lighter EIG [composition in ref.] will penetrate 1-inch of steel plate and will function (with less penetration) when vertical.

The advanced functioning of the EIG is the results of mechanical changes, the chemistry has not changed.

By the - "Stand off" distance is still critical for optimum performance.

grndpndr - 7-4-2010 at 14:09

Is it terribly far fetched the 'explosions', witnessed by a majority of civilians
who couldnt distinguish an explosion from high air pressure release As the WTCs 100s of acre sized stories pancaked causing explosive air compression/tremendous noise as the millions of pounds of concrete and steel impacted the floor beneath it?Of course they thought the impacting floors were exploding.Nothing mysterious or complex about that.Difficult to believe this is even being discussed seriously on this forum.

chief - 8-4-2010 at 00:14

An acre-sized surface needs more than a million pounds to compress air enough for explosive sound: Lets calculate:
==> 1 acre =~ 4 000 m^2
==> 1 Pascal is defined as 1 N/m^2 == 100 g /m^2
==> Say one Bar would be needed for explosive sound, then there would have to be a mass of 10 ton/m^2 (!) or 40000 tons per acre ...

.... maybe youre halfway right ... ; but: As explosion it only sounds if it's quick enough ... , else its just wind ... ; also a 1 Bar Air on each floor would have considerably pneumatically taken away the violence, like some damping-system ; the collapse would have to have been slower ...

I would estimate the pressure-rise to at most 100 millibar ...

hissingnoise - 8-4-2010 at 02:28

Grndpndr is 100% right chief - you're forgetting the sound of concrete sheet impacting concrete sheet. . .

chief - 8-4-2010 at 03:37

Whatever, back to the 15mm steel-rod: Say the idea would be to use a plaster-based thermite, to mechanically contain reaction for optimum-heat-transfer: Can plaster be made the usual way, just with aluminum-content, poured into shape and then be ignited ?
==> Or will it be too moist ? Do plaster-thermites function only with unhydrated CaSO4, or is hydrated stuff usable ?

Going to find out this weekend, but some previous inspiration would be fine ...

================

And while we were talking about some specific demolition: I read somewhere that
==> the inner core-columns were made to support 3 times the weight of the entire building
==> and the outer walls together could hold again 3 times the weight ...

With one destructed wall and a completely demolished inner core that would still make a capability to carry 3/4*3 == 9/4 of the total weight of the building ... right ?

[Edited on 8-4-2010 by chief]

The_Davster - 8-4-2010 at 10:06

Quote: Originally posted by chief

Whatever, back to the 15mm steel-rod: Say the idea would be to use a plaster-based thermite, to mechanically contain reaction for optimum-heat-transfer: Can plaster be made the usual way, just with aluminum-content, poured into shape and then be ignited ?
==> Or will it be too moist ? Do plaster-thermites function only with unhydrated CaSO4, or is hydrated stuff usable ?

Plaster can be cast the usual way. It will need to be dried in an oven at 90C for a while to dry it out.

The WiZard is In - 8-4-2010 at 11:33

Quote: Originally posted by chief

Because aluminium when milled is lubricated wetting it is...!
Spherical (atomized) is the easiest to use. As you are only
going to burn it ... use the lest expensive Al pwdr you have.

Drying to "constant weight" is recommended to prevent entrapped
water causing a steam burst. Any temperature will do your oven
does not get close it its ignition temperature.

The low albedo book sez. aluminium/sulphur will ignite it. I would
use one of the standard igniters

I don't remember, but I seem to remember you need K chlorate
sugar to ignite the Al/S. Do NOT use confectionery sugar.

Aluminium atomized (fine) 40%
Black iron oxide 29
Barium peroxide 31

Magnesium powder 9%
Barium peroxide 91

Silicon 40%
KNO3 54
Charcoal 6

Will ignite just 'bout any thing. The silicon results is a nice
hot dross/scoria of Si dioxide.

AMCP 706-185 Engineering Design Handbook
Military Pyrotechnics Series Part One
Theory and Application April 1967
[You can DL a copy of this and the other volumes in the Pyro series from the obvious US Gov web site.]

Sez —

Calcium Sulphate Thermite

Aluminium 40.9%
Sulphur 1.0
Castor oil 0.3
Calcium sulphate 57.8

I have never added sulphur or castor oil.

Checking my DB if find this comp was patented 1947.
US Patent 2 424 937, which see for details.

US Patent 5 490 888 and 4 381 207 are a variation.

I would mention in passing you can make firecrackers from
P of P and aluminium powder.

Byda you can read my article on the use of sulphates of oxidizers
in the Pyrotechnist Guild International bulletin.
The Few, The Proud, The Sulfates Bulletin No. 46

Microtek - 8-4-2010 at 13:25

I saw a video once (on roguesci) where thermite with an added gas generating component (possibly blackpowder) was contained in a ceramic "bottle". The device was pointed at a rebar and ignited from the open end, which resulted in a short but extremely hot jet of material from the opening of the bottle. This cut the rebar in less than a second.

IIRC, this wasn't an amateur experiment, but rather a video demonstration by some company.

I did a small scale feasibility test using "fireproof" clay as the container, and smokeless powder as the gas generant. It looked much like the demonstration in the video, but I didn't aim it at a target, so I don't know how effective it was.

Mr. Wizard - 9-4-2010 at 08:56

My personal opinion is there was no 'demolition' at the WTC. The heat involved in the fires and the destruction of both the sprinkler system and the heat protective coatings on the structural steel would be enough to ruin the strength of the building. Steel actually has a low specific heat and heats up quite quickly, hence the need for the sprayed on coating. Once the temperature reaches 900F it's essentially as strong as wet cardboard. I have seen building involved in normal everyday fires with twisted I beams that have sagged and failed. No exotic thermit, no shaped charges, nothing but burning wood and building contents. There are enough questions about the terrorist attack that are unanswered without looking for more.

As to cutting steel, has anyone ever seen a portable plasma steel cutter? A cutter could be operated from power available in the building, as could a portable compressor needed to operate the cutter. The cuts are very smooth, but are distinctive.

Panache - 12-4-2010 at 21:06

Quote: Originally posted by grndpndr

Is it terribly far fetched the 'explosions', witnessed by a majority of civilians
who couldnt distinguish an explosion from high air pressure release As the WTCs 100s of acre sized stories pancaked causing explosive air compression/tremendous noise as the millions of pounds of concrete and steel impacted the floor beneath it?Of course they thought the impacting floors were exploding.Nothing mysterious or complex about that.Difficult to believe this is even being discussed seriously on this forum.

i don't think it is being discussed seriously only that cut and paste comment by JohnW which i'm certain he doesn't agree with but it's been funny listening to everyone one pound down on the conspiracy, i mean its so ludicrous it hilarious, however Princess Dianna was killed by mi6/5 and that french mob upon orders of the queen and prime minister because she was carrying a islamic baby that had the potential to bring down the monarchy. I mean its obvious, makes perfect sense, lucky too as i'd be lost without my lordship stipend and title.

grndpndr - 13-4-2010 at 03:54

I Misspoke, I dont think anyone seriousy buys into a conspiracy theory on this forum.It is refreshing to see the 'conspiracy' roundly criticized
for a change.Its distressing to see the poll #s of how many actually believe there was some sort of gov conspiracy.If they tuly believe that wouldnt the be duty bound and morally obligated to respond vigorously?

Talk about anachronisms/ undeserved entitlements/welfare:
Anywhere top GB/'Royal'Family?

quicksilver - 13-4-2010 at 05:06

Quote: Originally posted by Mr. Wizard

As to cutting steel, has anyone ever seen a portable plasma steel cutter? A cutter could be operated from power available in the building, as could a portable compressor needed to operate the cutter. The cuts are very smooth, but are distinctive.

I'm glad you know that the "911 conspiracy" is BS. But as to plasma cutting - portables can't cut inches, they cut about 1/4 with SEVERAL PASSES. The power utilized would spike the electrical system on a secure structure as well as emit so much hi-frequency that it could not be done in a clandestine fashion. The duty cycle is only 20% for those if you're trying to really cut beams. The more professional cutters need a water spay.
The "911-Truthers" have been so roundly beaten in their fantasies that they have backed WAY off; except for the really stupid ones or the nut-jobs.
It just simply could not have happened. Such a "black-bag" job was just not the same as crawling around Vietnam's waters and saying the ship was further away.

JohnWW - 13-4-2010 at 05:59

The thousands of professional engineers (mostly civil and mechanical) and architects who are members of Architects & Engineers For 9/11 Truth, and who are better-qualified than you to judge, disagree with you, Quicksilver.See:
http://www.ae911truth.org/aboutus.php ; and also
http://www.911truth.org/ ,
http://www.911blogger.com/node/22725 ,
http://www.infowars.com/1000-architects-engineers-officially... ,
http://www.youtube.com/watch?v=ssuAMNas1us ,
and the video clips and full-length documentaries linked on
http://www.google.co.nz/search?q=%22architects+and+engineers...

[Edited on 13-4-10 by JohnWW]

bquirky - 13-4-2010 at 06:07

Off topic..

There is another possibly dangerous trend that seems to be emerging in society

that is the idea that conspiracy's are pure fiction.
and any interpretation of events or evidence that suggests something that could be construed as a 'conspiracy' is automatically an obsered fantasy.

The truth is that conspiracy's of all kinds are very real happen every day and result in real harm to people.

some examples are

the Archer Daniels Midland price fixing afaire
Amcor and Visy cardbord box price fixing convictions
the Watergate scandal
Evan the 911 plot was a true conspiracy

if someone had cottoned on to any of these things and started to talk they would have been laughed at as cranks.

groups of people sit around and plan nasty shit all the time and nasty shit can be well... nasty

lets bust out one right now..

Swine flue: real but massively exaggerated by vaccine manufactures,self justifying bureaucrats and politicians looking for a quick poll boost by 'swift action'.. now low and behold there are warehouses full of unused vaccines getting closer to expiring at public expense.. and whats worse. there are people out there in poorer contreys that could really be helped by vaccines for actual serious diseases

so.. did a group of people sit around and plan this ???

I dont know.. but isn't it worth looking into ? wouldn't you want to know ?

watson.fawkes - 13-4-2010 at 06:49

Quote: Originally posted by JohnWW

The thousands of professional engineers (mostly civil and mechanical) and architects who are members of Architects & Engineers For 9/11 Truth, and who are better-qualified than you to judge, disagree with you, Quicksilver.See:
http://www.ae911truth.org/aboutus.php

Well, I went and looked at this site, and its first paper, "Explosives Found in World Trade Center Dust". You can apply all the science and high-tech gear that you want, but if you're using it to justify a pre-existing conclusion, you're not doing science and you're philosophically unqualified to judge anything. And that's the character of this paper. There's not a single alternate hypothesis in the paper. It quotes uncritically that awful Jones paper I ridiculed above, the one that does reactivity experiments with no regard to surface area, even as this paper uses it to justify conclusions about "nano-thermite". There's no discovery or inquiry here; it's all of the form "this observation is consistent with our hypothesis". That's not science, but a form of religious practice called "proof-texting".

@JohnWW, you're making an appeal to authority that's not warranted. These people are profoundly not more qualified than the regular participants on this board.

The_Davster - 13-4-2010 at 10:49

It would be best for this thread to stay on the thermite topic and not on the WTC....

Nanothermite usually burns too fast for any significant heat transfer and would be useless for melting. It is being considered for primer applications and microscale propulsion, not for any thermal work...

gregxy - 13-4-2010 at 11:58

I have used plasma cutters and oxyacetelene torches to cut
steel and other metals. It is not the kind of thing you can
hide in an office envoromnent, lots of smoke, sparks, hissing
noise etc.

And why use thermite at all? A much smaller weight/volume
of HE cutting charges would be needed. And why place
charges on every floor? Cutting the floor that the plane
hit and dropping the building sideways would have the
same effect.

The common explaination of what happend at WTC is
completely consistent with the physics.

Here is a believable conspiracy theory (if you need one):
The CIA found 20 nice guys from the middle east, gave them
LSD and brainwashed them into hating America. Then
they trained them in how to fly jets, bypass security,
showed them the "target points" in the WTC gave them
the reqd. money and let them have at it.

grndpndr - 13-4-2010 at 13:29

Some folks do have a psychological need for a govt etc conspiracy
thus giving the act deeper meaning.Its unacceptable to thier sense of the world that a bunch of mutts could cause such pain.Every disaster I can think of manmade and natural has its conspiracy theory devotees.Not my conclusion look to the Pschiatric community.But it makes a lot more sense than "truthers".Hindenburg,Pearl Harbor,Camelot,Now 9-11.
Shit happens folks and I rather doubt its gods will or satans minions of yesteryear or government conspiracy now.

The WiZard is In - 13-4-2010 at 13:41

Quote: Originally posted by The_Davster

It would be best for this thread to stay on the thermite topic and not on the WTC....

Nanothermite usually burns too fast for any significant heat transfer and would be useless for melting. It is being considered for primer applications and microscale propulsion, not for any thermal work...

It would be best for this thread to stay on the thermite topic and not on the WTC....
Amen.

Now on to da topic.

It would be worth noting that aluminium iron oxide (all three work) is not the only thermite. Spitzer and Comet, Journal of Pyrotechnics 26 (2007) 60-64. Synthesis, structural and reactive characterization of miscellaneous nanothermites, for instance describes WO3 thermite.

The most common non-iron thermite is Cadweld® copper oxide/aluminium thermite used to weld copper, usually copper grounding wire.

Here do be a few others, from da Welding Handbook.

3FeAl + 8Al ----> 9Fe + 4Al203 (5590'F/3088-C) 719.3 Kcal
3FeO + 2Al 3Fe + AL203 (4532'F/2500-C) 187.1 Kcal
Fe203 + 2Al 2Fe + Al203 (5360'F/2960'C) 181.5 Kcal
3CuO + 2AI 3Cu + Al203 (8790'F/4865'C) 275.3 Kcal
3CU20 + 2AI 6Cu + Al203 (5680'F/3138'C) 260.3 Kcal
3NiO + 2AL 3Ni + Al203 (5740'F/3171'C) 206.6 Kcal
Cr203 + 2AI 2Cr + Al203 (5390'F/2977'C) 546.5 Kcal
3MnO + 2AI 3Mn + Al203 (4400'F/2427'C) 403 Kcal
3MnO2 + 4AI 3Mn + 2Al203 (9020'F/2771'C) 1041 Kcal
[One of these values is wrong! /djh/]

djh
-------
But science, spurred on by its energetic notions, approaches
irresistibly those outer limits where the optimism implicit in logic
must collapse. For the periphery of science has an infinite number of
points. Every noble and gifted man has, before reaching the mid-point
of his career, come up against some point of the periphery that defied
his understanding, quite apart from the fact that we have no way of
knowing how the area of the circle is ever to be fully charted. When
the inquirer, having pushed to the circumference, realizes how logic in
that place curls about itself and bites its own tail, he is struck with
a new kind of perception: a tragic perception, which requires, to make
it tolerable, the remedy of art."
Friedrich Nietzsche
The Birth of Tragedy 1872

Ramiel - 14-4-2010 at 00:25

Any more discussion of thermite in current affairs will be removed without comment.

optimizing the heat-transfer into the material

chief - 14-4-2010 at 04:16

The termal conductivity of the steel may play a role: To cut it faster than this conductivity permits
==> the surface, which faces the flame, must be blown off quickly enough, or reacted away ...

So maybe a non-equilibrium-process must be considered ...
==> A standard flame will transfer heat more slowly into the steel, heating it up halfway to the core ...
==> but a quick hot flame, with maybe reactive components, might eat the steel away more quickly than the heat can get diffused ...

Maybe that's why sulfur is said to be a component of some thermites ... : The sulfur-vapor or any oxide of it would at the temperatures maybe go sort of "through" the metal ... ... ; part of the heat would be produced by the reaction of the sulfur with the steel ...

=================

If the reaction would go faster than the temperature could be diffused, then it might be called a "thermal shockwave" ... :cool:

==> Ever anyone heared of such a thing ?

[Edited on 14-4-2010 by chief]

The WiZard is In - 16-4-2010 at 10:53

Quote: Originally posted by chief

Suppose I have a 15mm steel-rod and want to melt through it (just for sports, or because maybe it's too hard for any tool, and acid would take too much time ...) [Edited on 5-4-2010 by chief]

Back to the drawing board.

Band sawed an 4" length of 2" PVC in half, put on 2 band clamps,
mixed up 82 g aluminium (atomized was used for convince)
and 115g calcium sulphate (rounded values does not add to 200)
added water qs.

Poured in to the mold - inserted 1/2 bolt covered w/ tape,
when a bit hard removed bolt and enlarged hole w/ 1/2"
rebar.

Oven dried to constant weight. 170-180 gms. I forget.

Placed rebar on sawhorse with Ca sulphate thermite three
inches in. Warped Mg ribbon round... lite with torch ...
ribbon burns... nothing.

Time my trusty acetylene/air torch. Nice fire. Burns about
1/3 of its mass and falls off. Leaving rod hot enough to handle.

Next time ... find way to keep thermite in contact w/ rod
... use a LOT more. I am considering putting the thermite
in a flower pot so the aluminium oxide dross can run down -
flow over the rod, however. the aluminium oxide slag is not
very fluid, me thinks conventional thermite will be a better choice.

Will report back.

And a quick note for the pendantic-fussbudgets who do not
like my posts. Do you know how hard it is for me to
find material you don't find interesting - want to read?

Feel free to take your list of what you find acceptable
down the hall to the Chaplin's office and leave it there.
Free of charge the Chaplin will also punch your TS Card.

The WiZard is In - 17-4-2010 at 11:11

Quote: Originally posted by The WiZard is In

Quote: Originally posted by chief

Suppose I have a 15mm steel-rod and want to melt through it (just for sports, or because maybe it's too hard for any tool, and acid would take too much time ...) [Edited on 5-4-2010 by chief]

If fist you don't succeed use a bigger hammer.

Knocked together a 5" square box using 5/4 common pine
and my 2" stapler. Drilled hole for rod. Inserted plastic bag
filled with 500gm of aluminium/sulphate slurry. Allowed to harden.
Discovered P of P swells when it hardens. Remove on side
of box. Dry in oven to constant weight. Place cast thermite
in box. Screw side back on. Inset rod and two thermite campfire
starters (say 450gms). Added standard starting mixture
and a length of fuse. (I was not prepared to light this w/
my air/acetylene torch — put's me tooooo close.)

Nice display flames 3 foot in the air with white fire and
sparks. After 5-10 seconds. Bottom of box looks a volcano.
Knock scoria off rod --- red hot --- not melted.

The next try will be using iron oxide thermite where I can
get the molten metal to flow over the rod. Will make
a papier- mâché container using a flower pot for a mold.

Byda in thermite welding the heat the weldment to red
heat before welding so it doesn't suck the heat out of
the themite produced molten meal.

Looking out window see box is still burning.

Ok. Actually it wasn’t ok it didn’t work.

The WiZard is In - 8-5-2010 at 13:13

Quote: Originally posted by chief

Ok. Actually it wasn’t ok it didn’t work.

Stapled up a box from scarp plywood open at the top with a 5/16”
(arbitrary size) hole in the bottom. Made two side longer than the
over by ‘bout 3”. Dilled hole in longer of the two legs to hold a
length of ½” rebar under the hole in the boxes bottom. Appx. ¾”
below the hole.

After finding my eBay aluminium was aluminium paste (35%
mineral sprits) which if you do not remove it …. you convert your
Fe3O4 into nonmagnetic black mass.

After getting the mineral spirits out… mixed up 750 gms of 2.75/1
put it la box w/ the standard barium peroxide magnesium igniter,
because it was toooo windy too use magnesium ribbon, a first fire
composition and fuse was used.

Flame – smoke – sparks, pretty. Burns out… the molten metal
when it reached the bar cooled rapidly (which is why in thermite
welding the weldment is preheated to red heat) forming a blob,
which cooled the metal coming out of the box stopping the flow.
Result – a lot of iron in the now burning box.

If there were to be a next time – use a smaller hole in the bottom
of the box. Move the bar further away from the boxes bottom.

Use courser aluminium/black iron oxide. As you may have noticed
if you have watched La Myth Busters {who for whatever
reason used red iron oxide… then so did them on Save it keep it
(?)} fine reactants burn much too rapidly.

Engineering Design Handbook. Military Pyrotechnics Series : Part
One. Theory and Application (All 4 volumes are a fee DL)
sez. — … iron oxide scale [hammerschlag] and granular
aluminum. Large flake aluminium is no problem, “iron oxide
scale” is. Checking my ever useful copy of Graton and Sales,
Ore Deposits in the United States 1933/1967. AIME., to
refresh my memory. I believe the nearest magnetite mine to me
closed some years ago, alas.

chief - 9-5-2010 at 02:08

It didn't work for me either ...
==> all the heat goes anywhere, and maybe 5 % into the rod ... which doesn't even glow ...

The WiZard is In - 9-5-2010 at 07:09

Quote: Originally posted by chief

It didn't work for me either ...
==> all the heat goes anywhere, and maybe 5 % into the rod ... which doesn't even glow ...

Next up. Put lateral tension on the rod so it will pull apart if
melted — encase the rod in la box so it stays in close contact w/
the molten metal.

djh
----
In Italy for thirty years under the Borgias they had warfare,
terror, murder, bloodshed -- and they produced
Michelangelo, Leonardo da Vinci and the Resaissance. In
Switzerland they had brotherly love, five hundred yeas of
democracy and peace, and what did they produce?

The cuckoo clock!

(George) Orson Wells, 1915-1985
Speech added to Graham Greene's script for
The Third Man, 1949

Today's engineering failure

The WiZard is In - 9-5-2010 at 13:16

Quote: Originally posted by chief

Today's engineering failure —

Stapled together a 2 1/2 x 3 1/2" id box from ratty 1/2 plywood.
Drilled hole through and inserted 1/2 threaded rod, washer/nut
on one end, two compression springs on the other to pull the
rod apart when it melted.

Same old 750 gms 2.75/1 magnetic iron oxide/aluminium with
the standard BaO2/Mg w/ a Mg ribbon fuse.

Stapled ratty 1/2" plywood box's do not hold molten iron
really well! Melted one end of the spring and removed its temper.

Screwed together a 3/4" common pine 2 1/2" sq (inside dia.) box.
Filled bottom w/ an inch or so of Durhams Rock Hard Water Putty.

Will order up a strong spring from McMaster Carr on the morrow.

Standby for follow up.

Mr. Wizard - 9-5-2010 at 14:17

I would be real careful about using anything that had a water component in it to contain a thermite reaction. The worst case scenario has the reaction going to completion , with a big hot pool of molten iron, covered by white hot alumina, then the steam generated by the heat on the water putty, plaster, or concrete blasting the whole mass skyward into the air.

The WiZard is In - 9-5-2010 at 17:17

Quote: Originally posted by Mr. Wizard

I would be real careful about using anything that had a water component in it to contain a thermite reaction. The worst case scenario has the reaction going to completion , with a big hot pool of molten iron, covered by white hot alumina, then the steam generated by the heat on the water putty, plaster, or concrete blasting the whole mass skyward into the air.

-----------
Granted one can never be — Too rich, good-looking or safe.

Durhams Rock Hard Water Putty dries ... well rock hard.
Me thinks like concrete the water is part of a reaction and is
not available after hardening.

---------
Chemical demo goes out of control

An explosion occurred during a chemical demonstration at the University of Illinois,
Urbana-Champaign, earlier this month. The widely used demonstration of the thermite
reaction-which involves the reaction of iron oxide and powdered aluminum to form iron
and aluminum oxide-was part of the university's annual Engineering Open House for
local high school and grade school students. There were 200 to 300 people in the
chemistry lecture hall at the time of the explosion. Four teachers and 23 students were
taken to the hospital, where they were treated and released. The injured suffered first-
and second-degree burns and minor cuts. Chemistry professor Steven S. Zumdahl,
who was conducting the demonstration, says it had just been run successfully using
sand as a receptacle for the molten iron. But when the sand was replaced with water,
something went wrong. Jiri Jonas, head of the department of chemical sciences, says a
committee, including university and local safety experts, has been appointed not only to
determine what went wrong with the thermite demonstration, but also to review all
safety issues surrounding the open house.

March 12, 1990 C&EN23

Success

The WiZard is In - 12-5-2010 at 11:15

Quote: Originally posted by chief

Screwed together (well screwed together) a 2 1/2" id box from
3/4" pine. Drilled 1/2 hole 'bout 3/4" OC from the bottom —
1/2" threaded rod through. Used a (as described in the
McMaster-Carr catalogue) 1", 1/2" hole size, heavy load (Rate
lbs/inch - 230.4) 6" long, Steel Die Spring for pull.

750 gms of Fe2O3/Al 2.75/1 thermite, BaO2/Mg ribbon igniter.
Burns like a volcano — and yes the rod pulled in half.

Dripping thermite on the rod to melt it requires a courser mesh
iron oxide/aluminium than I currently posses to slow its burning.

I will stay w/ my plasma or oxyacetylene torch, WiZzer (pneumatic
cutoff tool) or if I really want to have fun pull it apart w/ either my
60 or 100 ton hollow cylinder - hydraulic ram. 5/8" and lager bolts
make a soul satisfying sound when they go, and if were not for
having a 5-gallon pail over the setup the bolt would hit the ceiling.

This afternoons project a wasp light for the tent caterpillars.
I usually turn them into tent caterpillar pâté with my 12 Gauge,
however, these are located just off the road. So.........