thermite

[eggi96]

I made thermite today with the bright flake aluminuim and red iron oxide to a ratio of 1:3. I put about 1 teaspoon of the mixture on a steel plate to see if it will do what its suppose to do and melt through it. All i got was a very bright flame and sparks but no melting occurred. Whats wrong with my thermite?

[Ralph]

I made thermite today with the bright flake aluminuim and red iron oxide to a ratio of 1:3. I put about 1 teaspoon of the mixture on a steel plate to see if it will do what its suppose to do and melt through it. All i got was a very bright flame and sparks but no melting occurred. Whats wrong with my thermite?

 

your thermite is fine its the user that is faulty

 

you need to have a conical hollow in your thermite leading to a small hole at the bottom this allows for the molten iron to be channelled down towards your target also elevating this above the target prevents blockages. Thermite isnt the reason it can be so destructive is unlike most pyro comps it has a molten reaction product. also using coarser al helps Ive had best results with DH 16mesh al (which contains allot of fine particles around the 300mesh mark also)

[dagabu]

your thermite is fine its the user that is faulty

 

you need to have a conical hollow in your thermite leading to a small hole at the bottom this allows for the molten iron to be channelled down towards your target also elevating this above the target prevents blockages. Thermite isnt the reason it can be so destructive is unlike most pyro comps it has a molten reaction product. also using coarser al helps Ive had best results with DH 16mesh al (which contains allot of fine particles around the 300mesh mark also)

 

A good terracotta pot with a section of 20 gauge sheet steel covering the hole in the bottom and a good flare composition in the center of the comp worked well for me. I did find that I needed about 10# of the mix to get a good melt going.

 

-dag

[Ralph]

A good terracotta pot with a section of 20 gauge sheet steel covering the hole in the bottom and a good flare composition in the center of the comp worked well for me. I did find that I needed about 10# of the mix to get a good melt going.

 

-dag

 

10lb ??? Ive successfully used a 1" ID tube with a piece of tape on the bottom and some mag turnings for ignition

[dagabu]

10lb ??? Ive successfully used a 1" ID tube with a piece of tape on the bottom and some mag turnings for ignition

 

Depends on what you are doing with it

 

I put this together for the high school science class two years ago for their Myth Busters segment. We put the pot on a car hood and lit it off, the fire department was doing training so we all worked together and even the local PD got in on the event and wanted to see what a "thermite bomb" was. Obviously, they didn't know what we were doing and they needed some training as well.

 

It went very well and we did melt into the engine and got the iron to melt to the oil pan before the fire department moved us back to fight the fire.

 

-dag

[Ralph]

Impressive I simply cut through a computer powersupply case (went in one end out the other) thats like 2mm each side

[Bilbobaker]

It's a very handy way to actually weld things together in the rough. Just takes practice and preparation.

[dagabu]

One of my pyro buddies is a train Engineer and he brought a few track repair kits. Its essentially thermite inside a two piece porcelain housing that is just clamped on the broken track and lit. He tells me that you only need to spot grind the weld if done right.

 

THIS looks a lot like the kit he brought over.

 

-dag

[eggi96]

Ah ok see i never knew i was meant to funnel the powder. Whats the minimum amount of powder you can use to burn a hole through a 5mm thick steel plate

[WSM]

One of my pyro buddies is a train Engineer and he brought a few track repair kits. Its essentially thermite inside a two piece porcelain housing that is just clamped on the broken track and lit. He tells me that you only need to spot grind the weld if done right.

 

THIS looks a lot like the kit he brought over.

 

-dag

 

I suppose the porcelain housing is a "one-shot" device. For multiple uses the best material I've seen or used is a mold made from solid graphite. Google Cad-Weld for more information.

 

Thermite reaction - about 1 second

Mold removal - about 6 seconds later

Touchable - about 10 minutes later

if I remember correctly!

 

Safety Tips:

-Always preheat/dry the mold and metal-to-be-welded with a propane torch before firing off the thermite shot (moisture in them will flash off as steam and create a hazardous situation).

-Don't forget to use a thin sheet metal dam (called a "coin" in the trade) to hold the thermite powder till it's molten.

-Remove the (reusable graphite) mold as soon as the melt has solidified and let it cool off in a safe place (without flammable material near)

-Ignite remotely and wear personal protective equipment (goggles and face shield, preferably with ~10 calorie rating, leather gloves and FR clothing if available or at least heavy cotton covering all exposed skin.

-Keep all flammable materials away from the area where you are using thermitic welding (unless the point is the Mother of all Fire Starters ).

 

WSM

[FrankRizzo]

Depends on what you are doing with it

 

I put this together for the high school science class two years ago for their Myth Busters segment. We put the pot on a car hood and lit it off, the fire department was doing training so we all worked together and even the local PD got in on the event and wanted to see what a "thermite bomb" was. Obviously, they didn't know what we were doing and they needed some training as well.

 

It went very well and we did melt into the engine and got the iron to melt to the oil pan before the fire department moved us back to fight the fire.

 

-dag

 

Sorry Dag, gotta call bullsh*t on that. #10 will easily burn through the hood and splash molten iron along the block and onto the ground, but you're not going *through* the block to the oil pan. The block has *way* too much thermal mass. I believe there was a UK science show that demonstrated this a few years ago.

[dagabu]

It was Brainiacs, just watch the video, it clearly comes out the bottom of the engine.

 

We had a Monza wagon with an all aluminum engine, the termite had no problem cutting through the engine.

 

Sorry, BS back at ya!

 

http://www.youtube.com/watch?v=rdCsbZf1_Ng

[FrankRizzo]

It was Brainiacs, just watch the video, it clearly comes out the bottom of the engine.

 

We had a Monza wagon with an all aluminum engine, the termite had no problem cutting through the engine.

 

Yeah, that's the video. Because of the way it was ignited, most of the iron is simply spewed out the top of the pot, and when the reaction finally reaches near the bottom, the hood is pierced and the the molten metal is dumped through. Notice that it doesn't really come out of the bottom of the engine (although that is what is said for dramatic effect), just splashes over the sides and onto the ground. The hole they show at the end is through the hood only.

 

An all-aluminum engine block is even less likely to burn through because of its ability to conduct the excess heat away to the surrounding metal. Do you have any video of your science project?

Edited June 3, 2011 by FrankRizzo

[dagabu]

Yeah, that's the video. Because of the way it was ignited, most of the iron is simply spewed out the top of the pot, and when the reaction finally reaches near the bottom, the hood is pierced and the the molten metal is dumped through. Notice that it doesn't really come out of the bottom of the engine (although that is what is said for dramatic effect), just splashes over the sides and onto the ground. The hole they show at the end is through the hood only.

 

An all-aluminum engine block is even less likely to burn through because of its ability to conduct the excess heat away to the surrounding metal. Do you have any video of your science project?

 

I was in charge of the blaster box, the fire department videoed it. It really doesn't matter to me that you are a cynic, I could show you video and you would claim it was faked like JFK's shooter or the Moon landing. Kenny Rogers gave some great advice when I was 10, "Know when to walk away".

 

If anyone cares to replicate the engine block thing, be forewarned, even draining the oil from the engine will not keep the motor from coming apart when all that molten iron comes pouring into the block! Keep back a bit.

 

Pic of the thermite coming out the engine oil pan:

 

http://www.pyrobin.com/files/thermite.jpg

 

-dag

Edited June 3, 2011 by dagabu

[FrankRizzo]

Dag,

 

That's molten metal flowing over the front of the engine, near the radiator. Once the hood was pierced, the metal dumped. I really would like to see your video, whether you had block penetration or not.

 

Edit: Or, is that a still from your experiment?

Edited June 3, 2011 by FrankRizzo

[dagabu]

Nope, it's from Brainaics. Again, I have no reason to debate a demonstration that took place in front off 150 people.

 

I would like to do it again though

 

-dag

[Mumbles]

Braniac has been known to fake videos before as well. There was something about the alkali metals like sodium, potassium, etc. They added one, perhaps rubidium and claimed it blew up a bath tub. It came out later that they actually had to use explosives to break the tub.