Working With a Post Hole Digger

Everyone's used a post hole digger at one time or another.

Clamshell Fence Post Digger

Whether you were a kid helping your dad put in a new mailbox, or you were building a barbed wire fence you probably learned the basics of digging holes with one of these two-handled torture devices.

In our work we've dug a lot of holes using everything from clamshell diggers to gas-powered hydraulic augers.

How hard you want to work to make holes is determined by: your budget, the size of your project, the type of soil you're digging in.

Trying to dig 25 holes in mixed clay, volcanic rock, and “hardpan” soils of Northeastern California with only a clamshell post hole digger will leave you frustrated, blistered, and sore with 25 4 inch deep holes in the ground. You're going to need to know how to use a digging bar to loosen soil and dislodge rocks to make your work easier.

For most do-it-yourself fence builders buying a hydraulic auger is out of their budget and the scope of the project, a little “elbow grease” is going to be needed.

Clam Shell Diggers

If you're digging post holes you are going to need more than a shovel. A clamshell is similar to two shovels facing each other attached with a ¾ inch pin that pivots the two blades to dig and scoop soil from the hole.

The "Business End" of a Clamshell Digger

There are some limitations to using this type of post hole digger because they are light and relatively fragile. . . so busting through hardpan and dislodging rocks can be difficult or impossible. Using a rock or digging bar in conjunction is often necessary.

In hard soil, if you are close to water use it to loosen the soil (don't even think about using your drinking water for this).

“Spearchucking” is a technique where as you drive your digger into the ground you release the handles just before impact. This will decrease the shock to your hands, wrists, elbows and shoulders. Trust me after a day of digging you will notice a huge difference in the way you feel.

Of course you are also going to need to take safety precautions before doing any digging.

• Always make sure to call 811 before you dig, it's a free service you should get in the habit of using.
• Wear good leather work boots (10 toes are important to proper balance)
• A good pair of leather work gloves (preferably broken in) is essential in preventing your hands from looking like a Top Sirloin steak at the end of the day.
• Make sure to wear a hat and use sunscreen.
• Stay hydrated: Generous amounts of water is important.

Mechanical Augers

Hydraulic Post Hole Digger

Hydraulic and mechanical augers look like a drill on steroids. They dig quick precise holes in all types of soil (but not through rock).

Augers can be attached to gas-powered motors like those on a “One Man” Auger and those attached to chainsaw powerheads, post hole augers can also be attached to tractors and Bobcats with hydraulic Power Take Off (PTO). If you need to dig a lot of holes or you're in tough soil, you may want to think about renting or purchasing one of these tools.

“One man augers” are considered relatively safe since they only kill one man at a time if you hit a large root or a rock.

Have a rock bar and shovel on hand to cut roots and dislodge larger diameter rocks, don't try to force your way through them unless you want to go for a ride. If you choose to use one of these devices make sure to lift the auger bit out of the hole every 8” or so to clear the soil and prevent you from getting stuck at the bottom of the hole (you may be surprised but dirt is quite heavy).

In my business I use the Ground Hog Hydraulic Earthdrill. It is a great tool and operates as advertised. It has a ton of torque, digs precise holes, and needs little maintenance. It is also very expensive to purchase thus out of the budget of most do-it-yourselfers, they can be rented from some larger rental centers and my be worth the expense.