Dexpan project, how to make the holes?

[Cord]

Watching Goldrush last night got us thinking about our rock splitting project. If you watched the episode last night, you would have seen them drilling and then cracking a large Boulder that was in their way. They used a product like Dexpan that expands as it cures. Our project is a simular, but a bit harder to pull off. Whereas they were only trying to split the rock, I need to carve a hole into bed rock. Not only do I need to drill the holes for the Dexpan like they did, but I also need to drill a series of perimeter holes for the rock to expand into. The hole will be below grade and will be roughly 10' wide X 15' long X 6' deep. The area is remote and is off the grid. Power is available by generator, water has to be hauled in. The pros would core drill the holes, but core drills are very expensive and require very expensive drills. THe Dexpan is expensive enough so it's not in the budget to hire the core drilling out. I own a skidsteer that has 30gpm capacity. Is it possible to use a hydraulic jack hammer to drill the holes? I've seen rock bits used on augers, but do they really work? I've used breakers in the past and they're not that effective because it's hard to displace the material.

 

[Gary Fowler]

We did a lot of rock drilling in Angola Africa for explosive charges to obtain quarry rock. They used crawler rigs with vibratory& spinning rock drills with compressed air to clear the hole and a vacuum system to trap the dust.
These machines were a bit more than your budget I suspect but they worked 7 days a week drilling holes for explosive charges which were set off twice a week. The rock was then put thru a crusher and used for road building. Larger pieces were used for filling in a section of the ocean to form a foundation for a new docking facility.

 

[Gary Fowler]

I forgot to add that we were limited in the amount of explosives we could use so as not to bother the building about 2 miles across the bay. We had to set up seismometers to record the blast across the bay just to keep the claims down about broken windows, etc.

 

[Stimw]

I wondered if they needed to drill their holes that deep to split the boulder?
I have found that once a crack is started it will run.
Have you ever heard of "Feathers and wedges" ?
You might try a HF rotary drill and Feathers and wedges. ???

 

[4570Man]

How big of a diameter and how deep of a hole are you drilling? You can rent a SDS Max hammer drill pretty cheap. Once you exceed the capacity of that your opinions are more limited.

 

[medic1050]

Check out the microblaster. The cartridges are the size of firecrackers. They are a 209 shotgun primer and small amount of smokeless powder. Use a rotary hammer to drill small holes blow them clean with air. Drop in 1 or 2 cartriges drop on the actuator press it down tight back off amd fire the system with compressed air. About as loud as a .22 cal so no worries from neighbours. Rock cracks fairly well. Especially with the 3 head system.

Ezebreak LLC Micro-Blaster – cracking rock and concrete

 

[Tractor Seabee]

I read an article discussing how they figure rock excavations were done before the days of explosives. They drilled holes in a downward angle, filled with water and waited for winter to freeze and crack the rock. Ala we are using the same principle except don't have to wait for winter. Then the ancients didn't put the value on time we do; they were not in a hurry, eventually over several winters they could have a large cave.

Ron

 

[quicksandfarmer]

Check out the microblaster. The cartridges are the size of firecrackers. They are a 209 shotgun primer and small amount of smokeless powder. Use a rotary hammer to drill small holes blow them clean with air. Drop in 1 or 2 cartriges drop on the actuator press it down tight back off amd fire the system with compressed air. About as loud as a .22 cal so no worries from neighbours. Rock cracks fairly well. Especially with the 3 head system.

Ezebreak LLC Micro-Blaster – cracking rock and concrete

What I like about this is that it only requires a 5/16" hole which is child's play with a SDS drill. Dexpan calls for 1-1/2" holes 12" apart and their website shows using a pneumatic hammer.

I have a 3000 watt inverter that I use to run hand tools off of my tractor's battery.

 

[Cord]

The product intrigues me, however I would have to say that I'd be blasting only 5' from the house. That said, it looks like a roll of scrap carpet and a couple semi tires are all that would be need to control the fly rock. Being that I'm diggin down 6' and you are limited to 16" lifts I'd have to drill, blast, break and excavate several times. That will add significant cost due to the need to rent equipment repeatedly. Neat product though!

 

[PILOON]

We have blue granit here and I've drilled many 3/4" holes with my SDS drill bits. (I have 20" bits.)
I have drilled more than a few as deep as 12".
Goes relatively fast. One trick is to let the drill do the work and don't push too hard.
It helps if air is available to blow the holes from time to time.

I'd drill a series of holes in a circular fashion all leaning inwards at the bottom and then load up with Dexpan

Google 'Dexpan' and see the film clips they have on site. Very interesting!

And as said, you can rent SDS drills., also Kango hammer drills.
I'd bet that overnight the hole core would practically pop out. That Dexpan is amazing stuff.