post hole digger recommendation

[stumpfield]

I need to get one to dig about 100 holes. What's the best 3PT PHD for decomposed granite? My soil is very soft on the top 12". After that, it's all DG material. Some areas are soft like compacted coarse sand while other areas are as hard as rock. Any particular brand or special type of auger bit? Thanks.

 

[Timber]

Charlesaf3, has a hydraulic PHD that mounts to the Fell of is B3030 with a tach-all. He has a picture of it in his avatar. The beauty of that one is you have the down pressure of the FEL. I personally have a Landpride PHD that I love. There is an optional down pressure kit you can buy for it. Regardless of what you buy be sure it has changeable cutting tips

 

[dfkrug]

If it HAS to go on the 3-pt, then you can get a low-flow hydraulic
unit (like the Worksaver 724H) and a down force kit. You will
want a rock auger with carbide teeth and that can run as much as
$1000 for just the bit, depending on the diameter.

Even the professional drillers don't want to drill into rock.

 

[N80]

When I worked on a line crew, as soon as we hit any real rock we pulled the augur out, got a jack hammer with a long round bit and dug a hole for the dynamite to go in. Then some local explosive guy would stuff a few sticks in the hole, we'd cover it back up, lay a big plate over it and park a back hoe on top and let her rip. I remember being very disappointed at the 'blast'. More of a thump. But it broke the rock all up and we could finish with the augur.

How can you tell if the augur teeth are replaceable?

 

[HomeBrew2]

I don't worry so much about what kind of digger it is as much as what kind of bit head it has. (Though a digger w/ down pressure would sure be good bet.) It's also not so much replacable teeth as it is being able to buy teeth anywhere and of different styles. My neighbor has a Bushhog auger that came with a Bushhog bit. ONLY Bushhog has replacement teeth and only one style and type of material, ie, no carbide. And, the tip is just as important as the teeth on the flights. It needs to be replacable and capable of different styles. A "Pengo" style headed bit is what you want to look for.

 

[3RRL]

I agree that the bit is they key, carbide interchange if possible. A hydraulic PHD would be great but the 3pt types like a Leinbach or something would do the job for 300 holes with a little elbow grease. The Auger, tip and cutting teeth is the key. They work on soft AND hard ground.

 

[Raddad]

If you buy a hydraulic unit and add the extra hydraulics on your tractor plus the carbide bit you'll be spending about $4,000.00! Thats $40.00 per hole!

 

[PBinWA]

I need to get one to dig about 100 holes. What's the best 3PT PHD for decomposed granite?

Somebody else's PHD would be best!

 

[N80]

Somebody else's PHD would be best!

Yep. I'm strapped for tractor cash right now and I'm planning on building a pole barn/shed for my tractor. So I think I'm going to borrow my B-I-L's ancient little JD with some ancient PHD on the back. They both still work fine and he usually comes with the loan! All the better. I only need 12 holes for the shed. I am planning on putting a corral in too which might require 20-30 holes so I may get my own PHD for that project. After that it probably won't get used much so I may go the cheap route and get something like a KK.

 

[johnk]

The KK will do just fine. Make sure you get a lot of shear bolts. I drilled over 300 holes with my KK and all I did was touch up the cutters with a file and it's good to go. I was using a 9 inch auger for all the 4x4 posts but just bought a 12 inch one. You have to be very careful in measuring doing a fence with 8" panels when digging the holes w/ a 9" because there isn't a lot of play to move the post back and forth. When you get one I would recommend the 12" auger instead of the 9 when you buy it. Just from my experience...

 

[Tom_Veatch]

The KK will do just fine.
...
When you get one I would recommend the 12" auger instead of the 9 when you buy it. Just from my experience...

I'll second that motion. I bought both the 9" and 12" augers with my KK PHD. The 9" auger is laying over against the wall somewhere, should still be bright and shiny under the dust, never been used.

 

[Atlas]

Somebody else's PHD would be best!

That's what I do. My neighbor has a PHD but no tiller. I have a tiller but no PHD. It's a fair trade.

 

[N80]

I'm going to use 6x6" treated posts for the tractor shed so I guess I'll need a 12" augur.

 

[Timber]

I didn't have any trouble with a 9 inch auger with my 6x6 fencepost. It is a lot easier to dig a 9 inch hole than a 12 in hole. Just put the hole in the right place to start with

 

[Slippy]

I have PH digger from TSC, was not expensive. I idle tractor as low as possible, and just set it on the ground. The teeth and bit will do the work. If it hits a rock it will jump and shake in the ground. At that point I bring it up about an inch and then drop. I do this again and again as it digs. If up put pressure on it and force it, it will shear the shear bolt. I can now dig tons of holes this way without shearing a bolt. Before, I would break a bolt on about every hole. The key is to keep the rpms low in my opinion. I also pull the auger up 2 to 3x to clean out the dirt as I go. This helps so that at the end of the hole you don't have a bunch to clean out by hand.

 

[Raddad]

Something is wrong besides lots of rocks or roots, if you're breaking that many shear pins.

I have a Land Pride PHD with a 7/16" grade 2 shear bolt on the input side. (The PTO) The augger has 2 each 1/2" grade 5 bolts holding it to the PHD. I run mine at about 1500 RPM on the motor which runs the PTO at about 300 RPM. The gear reduction in the PHD is 3 to 1 which translates into about 100 RPM for the augger. This is the speed Land Pride reccomends for a 9" auger. I have broken only a few shear pin bolts. I try to lower the PHD as slowly as possible while lifting to clear the hole 3 or 4 times. If you gradualy lower it into roots at high RPM it can cut them with more rotations taking a small bite each time arround. When it hits a rock it jumps arround before it can take too big of a bite and break the shear pin.

How do the rest of you run your PHD in various conditions and how many shear pins do you break?

 

[runningbird]

where is the shear pin?

 

[Raddad]

The bolt that holds the PTO shaft on the PHD is the shear pin.

 

[HomeBrew2]

I didn't have any trouble with a 9 inch auger with my 6x6 fencepost. It is a lot easier to dig a 9 inch hole than a 12 in hole. Just put the hole in the right place to start with

This thread is kindof broad based and it's tough to know who you replied to without using the "quote" feature. A 9" bit, in my view and those with more experience than I from many other threads, is fine for 6x6 fence posts. At least one poster spoke of a pole barn ... I can't imagine using anything less than a 12" auger for 6x6 barn posts. You need a lot of concrete for barn (structural) posts. To me, 12" holes seem small but also seems to be sufficient from what I have learned here on TBN.

 

[N80]

That was me talking about the pole barn. But think small. Just a 3 bay, open side, flat roof shed. We have dense clay soil here and I probably won't even use concrete. I'll dig the hole, put some gravel in the bottom and then fill a little gravel around the base of the post and then fill back up with dirt. There's an old barn on my place from the 1920's done this way with cedar posts. It is falling in all around but the posts are still solid as a rock. I think the 9" auger will be okay, but as Timber said, I'll need to get them in just the right place.