How do I dig a big hole?

[jmccalip]

This is for a Geothermal chiller project. Only need a 4.5F pull down.



I have a post hole digger, but I've only been able to go down about 4ft. The temp at the bottom is 79F when the air temp is about 90F. I need to go down lower, but I don't know how...

I'm trying to keep this semi DIY. I don't want to have to rent a huge CAT auger and tear up half the yard. I just want to make a hole. Any ideas?

[AnnArborBuck]

What type of soil are you on? Somebody on here just pounded a 3" pipe down into the ground and then pulled it out with a come along. If you are on sand this should be really, really easy. But being from texas I bet you are on clay. Could you trie soaking the ground to soften it up and then use the pipe. maybe hammer it down a couple of feet and then pull it out to clear the clay.

Let me know how it works out.

[jmccalip]

Yep, I'm on nice, bright orange clay. Once I hammer it in, how would I pull it up? I would never be able to grip it.


Here is a pic of what our top soil looks like:

[AnnArborBuck]

I would use some chain and a pully (come along) and use the pully to yank it out. If you only go in a foot at a time it should be easier to get out.

[harrisagogetter]

post hole digger work for ya.....

[Harold Edwards]

How low do you have to go?
Is there any more info on what you are doing?
I am really interested in this.

[skeeter_ca]

Rent a back-hoe! They're not that expensive and very easy to operate.

[beaniebeagle]

pound metal pipe into the ground....then attach something to it so that your car jack can push it up and out...may have to get a little imaginative

[Cuby2k]

IMO, if you are doing this project to save money, that is in lieu of forking the bucks over for a chiller, don't do it.

If it isn't done properly, sized correctly and controlled just so, it won't work and you will be out every dime you put into it.

The more I look at geothermal the more convinced I am that it is not all that feasible. Unless of course you live in just the right area with the right conditions and I am going out on a limb here, but, it doesn't look that way in your case.

I do not mean this at all in a mean way, I am just trying to be candid, like I would want someone to be with me.

Now, if you do go ahead with it please take lots of pics and please, please, please post your results. Good or bad, the more honest and accurate information that is shared the better chance for someone else's success.

Whatever you choose to do, good luck.

[jmccalip]

Originally posted by Cuby2k
IMO, if you are doing this project to save money, that is in lieu of forking the bucks over for a chiller, don't do it.

If it isn't done properly, sized correctly and controlled just so, it won't work and you will be out every dime you put into it.

The more I look at geothermal the more convinced I am that it is not all that feasible. Unless of course you live in just the right area with the right conditions and I am going out on a limb here, but, it doesn't look that way in your case.

I do not mean this at all in a mean way, I am just trying to be candid, like I would want someone to be with me.

Now, if you do go ahead with it please take lots of pics and please, please, please post your results. Good or bad, the more honest and accurate information that is shared the better chance for someone else's success.

Whatever you choose to do, good luck.

That is why I'm trying not to put much dimes into it. I doubt it will even work in texas since our soil temps are a bit higher than other areas. But I'm gonna try. I used the post hole digger to dig a 4ft hole, and I think I'll hammer in a 3" pvc pipe another 8ft down.

[jmccalip]

Ok, I got the pipe. I can hammer it in fine, but I can pull it out at ALL. Not even when it's 3" in. Can someone please help? How did that one person get it up??????

[oddiseus]

Just be thankful that you Don't live in Arizona, Caliche soil sucks and you couldn't move the ground without a backhoe.

[Sk8r]

You know you're on dead ocean bed and that red stuff goes WAY deep... Try a strap wrench, you know, those things you use with oil filters, and get a friend to help. You might also erect an A frame of pipe, and use a pulley at the apex to get added heave-ho upward. Continue to hose it down, and sink a wider pipe and a smaller one in the middle: hammer down the one to stay, so your soaked walls won't collapse, and hammer down the inner one to excavate. There's a reason most wells in the red belt are done with augers.

[jmccalip]

Update. We're diggin another hole with the post hole digger right under a 40ft oak tree. With some luck, we won't hit any roots.

We're about 20ft from the base, so I don't think we'll hit any large roots. Havn't so far.


We're choosing this spot because we'll be under a 12" limb, we'll then attach a winch to this and use it to raise the pipe. The limb should hold.....right?

[crustin]

i got an idea, why dont you call someone in china have them start digging and you meet in the middle, i bet its cold over there- lol - im sorry i could not resist

[Mishap]

Maybe I'm missing something, but when I dig holes in my yard I use a shovel, a pick, and some m80s......and a jackhammer once. Freakin rocks everywhere here.

[jmccalip]

I give up. Even the winch can't get the pipe out of the ground, and the pipe is only 6" in!!!! It was bending 1/4" steel chain links! I now have a pipe stuck in the ground. I guess I'll just saw it off and fill the hole in.

How much would it be to rent one of these? lol



It would be so much fun, even if I did it and it didn't cool my tank. lol

[AnnArborBuck]

Did you soak the ground first with water to saturate the clay? At least in my area (I live on clay, not texas clay) it is much eaiser to dig in the spring when the ground is saturated with water. If I need to dig a hole right about now I put out a soaker hose the night before and give the ground a good drenching. That helps to really loosen everything up so it should be easier to get it out.

[jmccalip]

It rained the night before. so the round was as soaked as it was going to get.

[r3tic]

go to a rental place and get a fence post puller

[sfsuphysics]

Got access to a pressure washer? You should be able to use that to cut a hole. Perhaps use that on your 4 foot hole to further make some depth. You'll end up making a ton of mud, but that should be easy enough to yank out. Just go a few inches remove, and continue. 1800psi works nice on dirt/clay/concrete

[edwardj]

What about using a heavy bar to loosen the bottom of the hole, then hammer the pipe in about 6" and use the winch? I worked in a nursery in highschool, and those bars are awesome tools.

Good luck.

[hahnmeister]

Ok, this is how I have done it...

Pound a metal pole into the ground as far as you want to go. Drop a 1/2 stick of lit D Y N O M I T E in the hole and let er rip. Holes in seconds.

[Rivalpc]

Originally posted by AnnArborBuck
Did you soak the ground first with water to saturate the clay? At least in my area (I live on clay, not texas clay) it is much eaiser to dig in the spring when the ground is saturated with water. If I need to dig a hole right about now I put out a soaker hose the night before and give the ground a good drenching. That helps to really loosen everything up so it should be easier to get it out.

Here in Maryland we have the same clay problem. if you need to dig through it filling the hole with water at night will help alot. you will also have to do it over several night or several times during the day. Fill hole, let soak, dig a foot, repeat.

[samtheman]

How will this hole cool water? Geothermal systems require many feet of buried tubing to be pracitical. Have you determined your ground temp? You need to know what temp. your soil is and at what depth to even begin to understand your cooling potential.