Liquid Dynamite

[DaveNH]

A friend of mine has a rock ledge in his yard.
He believes it to be shale. (multi-layer)
He wants to cut it back and re-use some of the pieces
for a wall. He mentioned that some one told him (a long time ago) that there was some stuff called Liquid Dynamite.
You drill a hole in the rock and pour this stuff in. The stuff
expanses, thereby cracking the rock.
Any one ever heard of this stuff and if so what is the brand name?

TIA
(BTW: He did not like the diesel fuel/fertilizer idea I suggusted.)

We're all in this together! (3)
Executive Ex-Yuppie Tractor Owner
<font color=orange>[Advertise your business here]</font color=orange><P ID="edit"><FONT SIZE=-1>Edited by DaveNH on 04/30/01 03:34 PM (server time).</FONT></P>

 

[MarkV]

Dave,

Never heard of liquid dynamite, although it sounds interesting. I do remember a post, from long ago, about drilling a hole, packing it with dry ice and putting hot water on it. I think run like _ell was in the equation somewhere./w3tcompact/icons/smile.gif I'm not sure anyone tried it, but the idea was rapid expansion would break the rock. I'd sure find a long distance way to add the hot water.

MarkV

 

[GlueGuy]

Could they have been talking about freezing water? Water is darn near incompressable (I think I spelled that wrong /w3tcompact/icons/crazy.gif, but I'm too lazy to check the dictionary)... but I digress /w3tcompact/icons/smile.gif.

When I lived in Minnesota, the science teacher had this neat little experiment that he did on one of Minnesota's famous cold days; as I recall, it was something like -30. Anyway, he set up a pail with warm water in it, then had these special little cast iron (or some kind of pot metal) balls that were threaded such that you could split them in half and screw/unscrew them. He opened up one of those balls (they were a little bigger than a hardball, but smaller than a softball), and held them under the water, filling them completely with water. Then, while they were still under water, he screwed them together.

We then went on a "field trip" up to the football field. He placed the (now loaded) ball on a little stand in the middle of the field, and we all got up on the bleachers and watched. When the water inside froze, that little ball went off like a hand grenade! /w3tcompact/icons/shocked.gif Pretty impressive, and no "explosives" were involved!

The GlueGuy

 

[AndyR]

I've heard of it - just can't remember where. Try querying the folks over at Yesterday's Tractors http://www.ytmag.com

Andy in NH

 

[EdDekker]

It is a grout that expands in the process of hardening. A row of holes are drilled and filled with the grout. The grout hardens and expands, splitting the rock along the line of holes.

There are several similar products including Bristar and Betonamit. There is a web page which explains the process [url]http://www.demolitiontechnologies.com/techinfo.html [/url]
and another is [url]http://www.onoda.co.jp/overseas/contents.html [/url]

Another option is to use Feathers and Wedges. Lee Valley Tools sells a small set and calls them Feathers and Irons. (See the link for a picture). Sets in various sizes are available from Trow & Holden (Barre VT) 1-800-451-4349 ( web page )


You can make your own Feathers and Wedges. The feathers are half round in shape and are tapered. The thin end is bent over to prevent them from falling into a hole drilled too deep.

Make the wedges with a angle that will complement the feathers. Make some thin with a sharp point and some thicker with a blunt end.

Drill the line of holes and place two feathers in each hole, and drive a wedge between them. Try to tap them in evenly, just one hit on each one in turn. If you bottom out one of the wedges and you can work it loose, switch to one of the thicker wedges.

The stone will split along the holes. You can hear the sound of the hammer blows change just before it lets go.



Ed<P ID="edit"><FONT SIZE=-1>Edited by dekker on 05/02/01 01:35 AM (server time).</FONT></P>

 

[MarkV]

Dekker,

Thanks for the web sites. That is some interesting stuff and it sounds like it can be used by the average person without a great deal of training. I have a few rocks that I sure would like to get rid of.

Any idea of the cost?

MarkV

 

[DaveNH]

Dekker
Thanks again for the info.

MarkV
My friend called and inquired. Cost for him was over $440
for two bags plus shipping to New Hampshire.
Looking at the website, those are some pretty deep and wide
holes you have to drill.

Think that there might be a cheaper (yankee) way!

We're all in this together! (3)
Executive Ex-Yuppie Tractor Owner
<font color=orange>[Advertise your business here]</font color=orange>

 

[RPM]

The way that slate quarrymen used to do it (it's a sedimentary rock just like shale) is to hammer wooden wedges into pre-drilled holes (or faults). When you have a line of these wooden wedges in you just go along the line and pour water on them. The swelling of the wooden wedges would crack large pieces of slate (boulder sized) off the face they were working.

The challenge is in getting a big enough rock-drill - you could try with a small hole (1 inch), but a smaller wedge probably wouldn't hold up to being pounded into it. You'd probably end up renting one no matter which approach you tried.

I grew up near some slate quarries - this old fashioned process supposedly served them well for centuries!

 

[EdDekker]

DaveNH,

There is no more classic Yankee way than to use feathers and wedges. Cut stone work from the Colonial or Federal period usually still show signs of the holes used to split the slab.

I have a few BIG boulders I would like to dismantle (another in my long list of future projects). For my project the big problems with Bristar (and Betonamit) are the price and the size holes needed. The Bristar is expensive but less than bringing in a crew with blasting-mats to split the rocks.
I can see using a medium or large hammer drill or a small demolition hammer to drill 1/2 or 3/4 inch holes in my granite for Feathers and Wedges. (The Colonial period holes were cut with less, something like a sledge hammer and star drill.) The holes would not appear all at once – I may take a few weeks, but they could be done. I do not see drilling a series of 1 1/4 or 1 1/2 inch holes for Bristar.


MarkV,

When I priced Bristar it was expensive, $400 for a 20kg case.




Ed

 

[Rch]

I've heard of building a fire on top of and alongside of a boulder for a day or two and then dowsing with cold water to crack it up. Has anybody had any experience with that technique?

RCH