rock buster? / post-hole digging tool

[Don A]

This topic probably straddles the line between farming and blacksmithing, so I figured I'd run it by you all.

I'm building fence. I own 10 acres of slate rock with a bit of grass here and there. We have a couple Scottish Highland cows, and I am expanding their boundaries.

About anywhere I dig, I will hit brown slate. That's pretty much a given. I went to the forge and modified one of those wood-handled scraper/digging tool things to help with the post holes. This tool works great on the brown slate; cuts it clean with a little persuasion. I managed to impress myself with the heat-treat on the tool :cool:

But then there's the blue slate.... this stuff will not give. Lay your anvil on it's side and try to cut a hole through it with post-hole diggers. This is kinda what I'm up against.

I've got some long pieces of 1" round stock with decent carbon content. I would like to forge a more aggressive digging tool of some sort from it. "Aggressive" defined as digging faster than one inch per hour.

Any ideas? :confused:

And don't tell me to move the hole. It could be the same anywhere.

Thanks,

Don

[Ron Hicks]

All we have is Chert rock here in NW Arkansas & when you do any post hole diggin got to use a Breakin Bar. I dont know what blue slate is but would say this old bar would turn it to dust right quick. The Chert rock Im talking about is hard stuff most people call it Flint rock.

The Breakin Bar I have is old made by a Blacksmith in Pea Ridge Arkansas. Made from an a Wagon axel . Its about 1 squareX 5 ft. long - with like a chisel point and a round tappered point on the other.
Its heavy and will make a man of you right quick.

I would say what you have will make a good bar - this old bar I dont think is hardened it is not real sharp. I think if it were to sharpe it would get stuck easy.
It has a slight bend in one end , I think it helps .
Ron

[Mills]

what Ron said you need a CROW BAR, we called them that in west texas cause a man looked like a crow using it, hopping up and down. 1 1/4 -1 3/4 rd about 5-6 ft long in 4140 should do the trick.

[HWooldridge]

We call them "spud" bars hereabouts. Usually as big as you can handle - point on one end and chisel on the other. I have made them 6-7 feet long - just depends on how stout the user is as a 20 lb bar will wear you out over a day's work.

Have you thought about renting a portable compressor and a paving buster? You could probably get done pretty quickly and not kill yourself in the process.

[Don A]

Have you thought about renting a portable compressor and a paving buster? You could probably get done pretty quickly and not kill yourself in the process.

Absolutely. But with too many jobs that require too much money, it is more cost effective to just kill myself

I appreciate the input,

Don

[johnny99]

I Alway's heard them called breaker bars, or tanker bars in the army. That's what I use also. Short of blasting,or power tools. I don't know of a better way for one man by himself to get it done faster.
Sorry.

[ThomasPowers]

Proper use of a spud bar: teenage boys wanting to impress your lovely daughters and their overprotective father?


Thomas

[Don A]

Proper use of a spud bar: teenage boys wanting to impress your lovely daughters and their overprotective father?


Thomas

HAHAHAHAHAHA!!!!!

You won't believe this, but a boy in my daugter's class (high school sophomore) stopped at the end of the driveway to talk while I was beating on that first post hole. Said he'd be glad to help any time... actually called me "Mr. Abbott". A polite lad; he's even a Boy Scout.

My conscience almost forbids me from using him as free labor, only to be forced to kill him when the job is done.

Almost.:cool:

[sjur.axel]

hi there. all new to the forum and all norwegian.
not quait shure what slate is? but im guessing its stone or clay.
if its stone then hammer drill ,welder a couple of screws and cement is the ticket. but if it is hard clay. we make a tool here in norway and scandinavia
thats been around for centuries. we forge it from 2 inch square ,ca 40 cm will give you about 8 kg witch is the weigth of the tool. its a long shaft/rod with a conical section in the bottom that tapers down to a point.
the point is 50 square at the start and tapers down to about 6mm at the end. the cone is about 25 cm long and the shaft is about 120cm long with an eye at the top (used to put a wood handle through) i`ve used c60w as the steel for it ,and its used unhardend. just drive it in to the ground and wiggel it about,and you have a nice big square hole to put the pole in. and then just sledge the pole in the hole :-) im starting to sound like an idiot......
but the tool is great. i even use it to break stone with.
-sjur axel-

[Ron Hicks]

For sure Don those young boys want to bulk up and get some hair on their chest - The ol breakin bar is just the thing for them:D

[JerryCarroll]

Don, around my place there is chert--pretty hard, in fact I've used pieces in my flint lock making good sparks! I made a spud outta a torsion bar from under an old '60s Plymouth--68 I think. Good spring steel. I've cut it up for adz stock but I'm thinking it was over 5' long. Heavy and strong enough to carve rock with after pounding an end to a half moon chisel.

[habu68]

Another idea, might be a pointed rod with a slide hammer like the tool used to pull dents from auto fenders.

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[Nick]

As far as terminology goes, we call them crow bars or pry bars around here.

And as for the stones, I was going to suggest something similar to what habu68 posted. I've used something like that to dig postholes in the Garden Peninnsula for the Boy Scouts. The Garden Peninsula is about 1' of dirt covering a bed of limestone, then more dirt, so a good rock-breaking aparatus was needed.

Ours was a solid bar with a thick disk welded about a foot from the tip. It then had a piece of heavy walled pipe with two handles that was raised and slammed down onto the disk. It worked well with limestone, though you may need something a little beefier with slate.

[Don A]

That slide hammer looks like it has possibilities...

But here's what I've come up with so far:

I had picked up a bent digging bar from the scrap pile at our fleet garage at work. It was about 4.5 ft and built for heavy work. Somebody got it tangled up with a backhoe or something and put a slight bend in the middle. I had thrown it in my scap pile to cut up for hardy tools.

After I started thinking about this yeaterday, I went out to our steel dumpster and happened to find a slightly rusted iron pipe. It was around 7 ft long with a 1.5" ID.

When I got home, I fired the forge to heat the digging bar. It is around 1.5" across. Handle area is octagonal, business end is square. I got it heated pretty good and then straightened most of the bend. Still not 100% straight, but close enough.

In the mean time, I chopped the pipe square on either end, then cut/ground a couple 6"x1" slots on one end. This would give me more welding surface than simply welding around the pipe opening.

I knocked the rust off the digging bar in the weld area, then slid the pipe over. I ran a couple passes over the whole joint and then dressed it up a bit with the grinder. I let 'er cool down and then covered the joint with duct tape (spare the duct tape, spoil the job ).

I ended up with what I guess to be about a 35 lbs., 7' long digging bar. It works pretty good, considering the stuff I'm beating with it.
But I was too worn out from tool making to get much digging done

Thanks to all of you for the input,

Don