Question about Digging Post Holes

flakrat · Jan 27, 2006

Howdy,

I live north of Birmingham, AL where the soil is a nice mix of red clay and sand stone rock.

I'm about to put up a horse fence that's going to require around 175 fence posts.

I've heard the best way to put the fence posts in is to use a post driver / pounder. I'm not sure if that'll work in my soil, so I may have to go the auger route.

I've had someone tell me that digging the holes with a 3 point hitch mounted auger would be a pain in the butt because it's difficult to get the auger to stay straight up and down as it digs the hole.

He says that I'd spend a lot of time lining it up for each hole.

His suggestion was to get one of those hand held two man augers.

I bought my tractor to do the hard work for me, and digging close to 200 2 foot holes using a hand held auger sounds like a lot of work.

So, what are y'alls opinions on 3 point hitch mointed augers? Are they fairly easy to line up and use, or are they more trouble than they are worth?

Tractor: Kubota L2800 HST 29hp

hudr · Jan 27, 2006

If I have several holes to dig (more than 1) I hook up the 3pt auger. Its a pretty simple matter to keep it straight once the hole is started. You may have to inch forward or back at first to keep the hole straight. Once the hole is started I can let off the brake and the auger seems to find its own plumb line. Of course, I use a 9 inch auger then put no bigger than 4 inch pipe in it for fence corners, so I have a little play. If you are going for an "interference type fit" you may have closer tolerances on hole straightness (is that a word?).
Anyway, I never liked the idea of luggin around that two man auger/motor or grabbing hold of it to start a hole. Seems to me SOMETHING is going to spin, either the auger or the motor (then ME). I think my 2.5 ton tractor has a better chance of holding on if the auger hits something. /forums/images/graemlins/grin.gif
Disclaimer: I am on sandy loam, so all this advice may be completely wrong for your situation /forums/images/graemlins/grin.gif

Jimbrown · Jan 27, 2006

My opinon is that the tractor will dig a straighter hole than any two man auger and you better be one big strong guy to use the two man thing. You did not say what kind of post you are putting in. If they are T post the pounder will work best. I have put up about 2 miles of T post fence here in Arizona. The ground is about as hard as anywhere. I pound the T post and dig holes for all of the corner post and cross brace post and cement them in. There are places my auger will not dig but in the places where it will it sure makes it a lot easier.

flakrat · Jan 27, 2006

Oops, sorry.

We are planning to use 4 or 5 inch diameter round pressure treated wooden posts (7 to 8 feet long). We are putting up a vinyl stretch fence like this:

Another question popped into my head, how big should we make the holes for a 4 inch diameter post? For the general posts, we are just planning to tamp dirt down into the holes, and for the corners we'll use concrete.

Gate posts will be 6 inch diameter or so.

QRTRHRS · Jan 27, 2006

You won't know until you try how the pounding will go but it makes a tighter installation especially in conjunction with the Centaur type of fencing. I have worked an hour with a 3pt auger and digging bar setting a post where the pounder could not get to. Just 12 feet away the pounder had no problem. Those posts are blunt too, not pointed. Wet ground will help the pounding.

Although voiding the warrenty, I did not use concrete to reinforce my corner posts. Rather, I put in "H" braces which have held up quite well.

Like suggested before, forego on the two man auger.

Bob_Skurka · Jan 27, 2006

I'd use the 3pt PHD with a 9" bit. Its a good all purpose bit and will give you a little bit of play in the hole for adjusting to plumb. Also I'd agree that you can dig a plumb hole by inching the tractor slightly forward or back while the bit goes down.

I've rented a 2 man post hole digger. I did it once. I got kicked by a mule once too. I won't rent a 2 man post hole digger again. I won't make the mistake of walking behind a mule again either.

MMM · Jan 27, 2006

If terrain is hilly a 3pt auger can be difficult to dig plumb, straight holes unless tractor is positioned correctly. Such instances as a fence paralelling a slope you will have to position tractor perpendicular instead, which means you can't just drive down the line, drilling. I like a hydraulic auger because they normally dig straight no matter the incline by hanging off 4way swivel mount. You won't have a clutch or shear pin to deal with and they're reversible if you get in a bind. They are a little more spendy than even a quality 3pt pto model though.

ToadHill · Jan 28, 2006

If you use a 9" auger for a 4" post you should have plenty of room to keep the post plumb when you set it and backfill. I use that size auger and black locust post's that are about 4 or 5 inches. Our soil is 14" then clay with a lot of rocks, the 9" auger cuts through it just fine.

rambler · Jan 28, 2006

Your 'someone' is full of it, & pulling your leg.

The easiest way to go is the pounder, but no way to say it will or won't work without just trying it.

The pto mounted is the next best way to go, assuming you can drive to most of the post locations.

I would rather dig the holes with a hand powered auger than those 1-2 man gas monsters. Yish.

I would agree the 9 inch is a good general auger size for your needs.

In my soil & climate, a wood post set in concrete is a real mess, it rots out quickly & you have the chunk of worthless concrete to deal with. Your conditions may vary?

--->Paul

CurlyDave · Jan 28, 2006

If you absolutely insist on using something other than your tractor, use one of these:

One man hydraulic PHD

Standard one-man or two-man augers have led to a lot of back injuries when they catch on a root or a rock.

Your tractor is really your best bet.

automech · Jan 28, 2006

I have rented a post hole digger that had the engine separate from the auger. The engine was on a wheeled frame like a generator, and had a flex shaft of some kind leading to an auger bit with a 2 man handle set up. There was an anti torsion bar set up between the motor and auger so the auger handes wouldn't kick. It worked pretty good and was safer than the type with the motor mounted on the auger type. I would prefer owning and using a 3 pt type though.

MikePA · Jan 28, 2006

I've dug post holes with a shovel, a clam shell digger, a 3ph post hole digger and a post driver. The best one, by far, is the post driver. Turns a 2 step process into a one step process.

BGL990 · Jan 29, 2006

I agree. I'm actually surprised that so many people seem to use augers rather than post pounders. Around here if you were putting in a regular field fence with an auger people would look at you funny and ask how many weeks you plan to work on it. /forums/images/graemlins/grin.gif

It takes 30 seconds to put in a post in soft-ish soil, a few minutes in hard clay with a pounder. Also, short of actually cementing it in, the post will be as tight in the ground as it can possibly be. Having said that, I have found it is not always easy to keep the post absolutely laser straight and vertical with a pounder, especially if the post hits a rock underground. If you are looking for perfect alignment, the auger/cement route gives you a bit of leeway to adjust each post. If the odd post being a couple inches off center or leaning a couple of degrees won't cause you to lose sleep, go with the pounder and get it done in 1/10th the time.

/forums/images/graemlins/cool.gif

ps. the posts do need to be pointed to use the pounder (unless perhaps if your soil is extremely soft)

cisco · Jan 29, 2006

Pounder works fine in soft or particularly wet soil, and even then it helps to have a somewhat pointed tip. If you've hard soil and/or rocks, a pounder can be frustrating (split posts, crooked posts, etc). An auger works on any kind of dirt, wet or dry, but larger rocks are an issue. For a 4X4 that you're not planning to put cement around, a 6" auger is fine. For cemented in corner posts, use a 9" auger. You can always get a 4X4 straight in an augered hole, as there's so much "play" around the sides of the hole to work with. As to lining up the auger - it's mounted to your tractor and swings downward in a bit of an arc, not much but enough to put the hole slightly off center. Just drop the auger tip where you want it, and drive your tractor backward an inch or 2 (depending on the arc of travel of the auger head). Should work fine.
As to a 2 man hand held auger - HOW many posts was that you needed to seat, and how strong is your back?

MikePA · Jan 30, 2006

<font color="blue">ps. the posts do need to be pointed to use the pounder (unless perhaps if your soil is extremely soft) </font>
I had a different experience. My soil is not 'extremely soft' and I did not have to put a point on any of my posts. 180, 4" x 4" x 8' posts went right in.

BTW, people use augers instead of post drivers for 2 reasons. Augers are a lot less expensive (less than half the cost of a driver) and can be used for other purposes.

Mosby · Jan 30, 2006

We are finishing up our last stretch of close to 500 hundred sections of board fence. We have drilled all of them this time. I had a driver on our last place which a lot more rockier than this one. It worked great when the ground conditions were right, and was somewhat frustrating when it wasn't. It was a front mount and I had to have someone on the ground to help.
I'll offer this on the auger. To remove the play or slop from left to right, be sure to tighten the lift arm turnbuckles after you hook up. It makes a world of difference. For those that have issues keeping the hole straight, that is it quite often. You can then adjust side to side by using the adjustable lift arm.
I lay off mine with dots of paint. On the hills, I always head down. If the auger is swinging, I touch it to the ground to stop it and then line it up on the paint. Once it starts, (if on a hill) I let the tractor roll forward just a little bit and have no problems with them being straight.
I always try to be sure that I have enough room around the post to allow the head of the tamping bar to fit all the way around. When I have had or seen problems is when the post is set to one side and the tamping bar doesn't fit all the way around. That is why the layoff can be so critical.
I actually have a college kid tamping all of them for me. I drill the holes around his class schedule and weather and he takes over from there. I HATE tamping posts.

BGL990 · Jan 30, 2006

I stand corrected. I should have stated that I haven't actually tried driving non-sharpened posts, but I wouldn't have imagined it working too well. Other than a couple wet swampy spots, the "soil" around here is rocky blue clay that is just slightly softer than concrete. No points = shattered post in this stuff. I suppose my definition of "extremely soft" might be someone elses definition of "normal" /forums/images/graemlins/tongue.gif

Re. the pounder being more expensive than an auger - yup they sure are. Unreasonably expensive to buy IMHO, but if you don't have one they should be pretty easy to find for rent. We got lucky and found an old Farmall M with front mounted pounder for $800. Its conversion to 3pt mount for use with my 990 will be the subject of a future DIY posting on this board someday ...

slowrev · Jan 30, 2006

Unless you hit solid rock a pounder is the ONLY way to go. Here we have clay and slate rock and a pounder just pokes them on down. Much faster and easier. My friend and I could set those 175 posts in one day with a pounder, depending on terrain of course.

Ben

RobertN · Feb 1, 2006

I found my 3pt auger does not work well in my clay/rocky soil, mostly because of no down pressure. 3pt PHD's with down pressure are available though... I tend to use a combination of Auger and 40lb Makita electric jackhammer...

If you do have to rent an auger, go rent a skidsteer or tracked loader with an auger. That's the way to go... Or, pay someone to do it. Around here they get about $5/hole...