Non-explosive demolition agents | Hacker News Reader

Non-explosive demolition agents

en.wikipedia.org

58 pointspraptak26 comments

And not a single link where to buy them :-). The only non-explosive demolition agent I've used is composed of 'oak seedlings'. Wherein you plant an oak tree and its roots go out and demolish sidewalks, foundations, etc all around it. Takes a while though. :-).

What I'm missing from that article though is the application process I guess. We would get water freezing in pipes that would ooze out the tops (if the pipes were sealed they would fracture but not if the pipes were open). How would one 'seal' the bore such that the expansive force of the agent used was directed outward toward the thing you were breaking up rather than popping out of the bore hole right back at you?

It expands in all directions so it locks itself in place.

Presumably it hardens first to self-seal and then slowly the solid expands?

But this[1] documentation implies it can expand as a liquid: "Forceful BLOWOUTS may occur once mixed with water! Keep safe distance. DO NOT look directly into filled holes. Use of Dexpan® in hot weather could increase chances of blowouts. DO NOT pour into hot holes. Use iced water in summer.".

[1] https://images.thdstatic.com/catalog/pdfImages/1d/1dc6a35d-8...

Timelapse video if it in action over 24 hours: https://www.youtube.com/watch?v=lsDh92nvdzw

Given the safety warnings on that link, I was expecting something far more energetic.

No, it takes a long time depending on the product and doesn’t really self-seal per-se. It just hardens in the hole and kind of draws down into the hole in the first few hours…

You drill a hole and then mix and fill it. This product and its competitors is generally like a pancake batter. The product sits in the hole and becomes hardened fairly quickly as it reacts.

Generally I’ve seen it do cracking work overnight (like 12-16 hours), though most of the time when I’ve used it 2 days show the full results you’re going to get. It can really take some time.

I’ve split absolutely massive boulders with this stuff. As big as houses with a 3.5’ foot hole. Often the cracks will run hole-to-hole so you have to really think about the pattern to break the rocks.

Here you go mate: https://www.dexpan.com/collections/dexpan-demolition-agent/p...

45 dollars for an 11 lb bucket of "expansive demolition grout".

Back in the day Las Vegas pool contractors (who installed backyard pools) included a clause that said "If we hit caliche (aka 'desert concrete') the deals off, we'll re-fill the hole and leave." And yet this stuff could break it up it seems. I wonder when these things became "off the shelf", presumably after the 70's.

Seems like a win if you are a gardener looking to get the soil turned.

True. But the product wouldn’t be great around gardens because it’s pretty dang toxic.

https://cessco.us/files/DEXPAN__Non_Explosive_Demolition_Age...

I’ve used it, and many competitors, and you need full PPE to handle. Great stuff though.

It's table salt, rust, sand, and ceramic. It's not toxic in the least. Corrosive, yes. Breathing in silica is not good long term. But it's about as toxic as beach sand.

Well say what you want about it but I wouldn’t want to have a plate full of vegetables grown in pure Calcium hydroxide and the stuff is terribly unpleasant to use even if it isn’t technically “toxic” in the literal sense.

Here’s the safety information:

SKIN CORROSION/IRRITATION - Category 2

SERIOUS EYE DAMAGE/ EYE IRRITATION - Category 1

SPECIFIC TARGET ORGAN TOXICITY (SINGLE EXPOSURE) (Respiratory tract irritation) - Category 3

This is just Dexpan, but here’s the safety data sheet:

https://cdn.shopify.com/s/files/1/0015/7777/9270/files/dexpa...

Do bear in mind that they don’t disclose the full formula for competitive reasons so we don’t really know what all is in it.

Bon appetite!

To be fair, growing stuff in what constitutes "soil" in Las Vegas back yards is kind of hit or miss. As a kid, with my parents help, we eventually managed some decent gardens by building a raised bed and filling that with something the plants could deal with. :-)

The point is valid though, it will throw off the Ph quite a bit if you have it mixed in with what is left of the caliche.

One of the houses on the block where I had lived refilled the hole, left when the pool contractor threw up their hands, with agricultural fill dirt. They had a very nice yard.

Demolition Grout.

https://www.homedepot.com/p/Dexpan-11-lb-Bucket-Type-2-50F-7...

I’m kind of surprised environmental or social activists haven’t used this product to destroy statues. Not advocating for it but busting things up seems a little more newsworthy than gluing yourself to stuff.

You'd have to spend a lot of time drilling holes in a very hard material and awkwardly pouring the product into the holes. Not exactly a discreet way to destroy something.

If you want to destroy a statue, I suspect a sledgehammer is easier to apply, cheaper, faster, more newsworthy on video, and considering the need to drill holes to use this, possibly stealthier too.

It’s pretty damn conspicuous to use. :)

A legend says you could place some diesel or similar fuel in the drilled hole before topping it off with this stuff, presumably leaving some air in between, to enhance the effect by igniting the fuel as the pressure and temperature rise. I can't attest to the effectiveness, legality or safety of this method.

What is the Monroe effect, and why is it important?

Chat GPTs's response to this prompt:

The "Monroe Effect" you're referring to seems to be a variation or misinterpretation of the "Munroe Effect," also known as the shaped charge effect. This effect is a well-known principle in explosives engineering and military technology. It describes how an explosive charge can be shaped to focus the energy of an explosion in a specific direction. This is typically achieved by hollowing out a portion of the explosive, often in a conical or lens-like shape. The concept was developed by Charles Munroe in the late 19th century.

In a shaped charge, when the explosive detonates, the hollowed-out shape focuses the explosive force into a high-velocity jet of metal that can penetrate armor or thick materials very effectively. This principle is used in various military applications, including anti-tank warheads and improvised explosive devices (IEDs).

The post you are referring to seems to suggest a makeshift application of this principle, using a drilled hole and fuel to create a focused explosive effect. This kind of improvisation is extremely dangerous, unpredictable, and, in most cases, illegal. It's crucial to understand that handling explosives without proper knowledge, training, and legal authorization is hazardous and can have severe legal consequences.

I hate auto correct.

https://en.m.wikipedia.org/wiki/Plug_and_feather

Beavers. A swarm of beavers. You have no idea unless you've done actual combat.

Was expecting something like gallium on aluminum.

Small kids' saliva. Ivy and other climbing plants. Termites.

There's a story that the Egyptians/Incas/old civilizations split rocks with wood and water. The swelling pressure of wood breaking the rock.

I can't see any videos demonstrating it. I'd go with it's a myth like most of history.

I wonder if you filled it with water and put a little freezer over the top it'd work.

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