Help! Jackhammer is stuck in concrete

[Monkeyleg]

I'm rebuilding the 300 feet of 6' fence in our backyard, as it was looking pretty shabby.

I'd had to remove one of the corner fence posts when my wife's gazebo was delivered in order to able to get the gazebo through. I had to use a truck and a chain to pull the fence post, and of course the 6"x6" fence post cracked at ground level.

Soooo....I got a twenty-something neighbor to help me with the project, and had him bust up the concrete. The sledgehammer wasn't doing much, so I rented a 20 pound jackhammer this afternoon. The 20 pounder wasn't enough. It's now stuck in the concrete, about 2 feet down in the hole. Turning the locking knob for the chisel to release the chisel doesn't work. I don't know why. Pulling on it won't get it out, even with the power turned on, as the hammering action only works going forward, not in reverse.

Right now the only thing I can think of is to rent a 60 pound jackhammer tomorrow morning, and use that to get the 20 pounder out (I hope), and finish the job.

Any other ideas (besides detcord)? This project is headed over $1100, and more rentals don't help.

[PTK]

...I had to read the title twice. That's quite an issue, but unfortunately there's no easy way to remove the 20lb hammer. I assume you've tried smacking the side of the chisel, if any of it is still exposed? If not, give it a few good whacks with a sledge hammer on all the sides, and then try to lever it out a bit at a time.

And yes, if it got stuck, you need a bigger jack hammer. Once it's free, return the 20lb one.

[zxcvbob]

Can you wrap a chain around the chisel and use a winch or a hydraulic jack to pull straight up on it?  Either the chisel will come loose or the whole post will come out of the ground, and either way you win.  (or you'll break the jackhammer)  

6x6", I would have tried to dig/pull it up rather than break it apart.  That's probably not a lot of help now...

[geronimotwo]

a twenty pound jackhammer should be able to handle what you are doing.  chances are you got it stuck in the wood?  there should be a way of removing the bit, then you can use one of the other bits to get the first one free.

i onse did a fence that was on a property line of bad neighbors.  i drilled and chiselled the wood out of each footing to place the fence exactly where it had been in the first place.  about halfway through the neighbor who hadn't hired me told me i had moved the posts further onto his property.  then i showed him the original footings, and he fell silent.

good luck!

[seeker_two]

Help! Jackhammer is stuck in concrete

Oh....that jackhammer....I thought it was code language for something personal.... 

[bedlamite]

Right now the only thing I can think of is to rent a 60 pound jackhammer tomorrow morning, and get that one stuck too.

Just another possible scenario.

[280plus]

Yup, I think I'd be trying to work it sideways either by leverage or hammer. Try to work the hole diameter bigger.

[AJ Dual]

Can you wrap a chain around the chisel and use a winch or a hydraulic jack to pull straight up on it?  Either the chisel will come loose or the whole post will come out of the ground, and either way you win.  (or you'll break the jackhammer)  

6x6", I would have tried to dig/pull it up rather than break it apart.  That's probably not a lot of help now...

This, plus soak the ground around the concrete post footing with the garden hose first.

I was able (albeit not easily) to pull some 8" wide 3' deep concrete footings for chain link fence posts out of the ground by hand like this. Use a hammer drill and sink an anchor and big eye bolt into the concrete, or even just the jackhammer itself as the anchor point for a loop of chain. You might be able to do it with just cheap Walmart ratchet cargo straps, rescue tow strap, or even just a loop of chain, and a suitably long/strong lever, like a chunk of timber, as long as whatever you use as a fulcrum is sturdy enough. (another small stack of timber)

[Ben]

That's what she said.

(should apply to nearly every response in the thread). :)

[never_retreat]

What type of hammer is it? maybe that could help determine how to get the bit loose.
Then get another bit and break the first on free.

Mental note.
Never drive a chisel straight down. Work at outwards angles breaking it off piece by piece.

[Tallpine]

Maybe you could just buy the jackhammer and use it for a post 

[Azrael256]

What you need is to find the King of the Britons.     I hear Merlin had the same problem.

Download the manual for the jackhammer and figure out how the chisel comes off and use another chisel to dig out the first one.

Alternatively, a large sledgehammer will fracture stressed concrete if you can get a good angle on it.  If you have a good drill and a masonry bit, you can drill holes to give it a good path to crack.

I'm sorry, but I'm laughing hysterically at the thought of this.  Don't run a jackhammer in a straight line downward.  It will get stuck.

[Monkeyleg]

I read the manual for the jackhammer online. We were going by the book in trying to remove the chisel from the jackhammer body. For whatever reason, the jackhammer and chisel won't separate. The chisel went in easy enough, and the locking mechanism turned easily.

It's a Makita 20 lb electric model.

I'm sorry, but I'm laughing hysterically at the thought of this.  Don't run a jackhammer in a straight line downward.  It will get stuck.

I obviously didn't know that.

This is down deep enough now that even getting alongside the remaining concrete would mean digging a very large and deep hole. Maybe that's what it's going to need. Don't know yet.

6x6", I would have tried to dig/pull it up rather than break it apart.  That's probably not a lot of help now...

This piece of concrete is about 2 feet across and at least two feet deep. Massive overkill when they poured it. It's also going underneath the neighbor's driveway a bit, so I don't know about trying to pull it out.

I do know that at 8:30 tomorrow morning I'll be paying for a full day rental on the stuck jackhammer ($75 a day), and then will be paying for the rental of a bigger one.

[Jim147]

Go back to the truck and chain you started with and see what happens.

jim

[Boomhauer]

I've got one of the Harbor Freight electrick jackhammers and I like it a lot. Jackhammering is all in the technique, you have to cut and fracture to break the chunks out/off, not go at it directly or try to jackhammer straight down. Really helps to have a spotter, too.
http://www.harborfreight.com/25-horsepower-industrial-breaker-hammer-kit-96035.html

[Monkeyleg]

Go back to the truck and chain you started with and see what happens.

Right now the only thing to grab onto is a stub of the 6" x 6", and the angle is such that it would be pulling against the side of the hole.

Jackhammering is all in the technique, you have to cut and fracture to break the chunks out/off, not go at it directly or try to jackhammer straight down.

So I've learned.

I don't have anything but a big auto floor jack, and even with the amount that can lift, I don't think it would move this chunk unless the hole is dug much, much bigger. I guess I'll just get another, bigger jackhammer and remove small chunks.

The last time I used a jackhammer was about 30 years ago. We were removing a vault from the first floor of the studio I worked at. The walls were 2' thick steel reinforced concrete. There was about three feet between the top of the vault and the joists for the 2nd floor, so we had to kneel in that small space with those big jackhammers. Lots of fun.

[zxcvbob]

There was about three feet between the top of the vault and the joists for the 2nd floor, so we had to kneel in that small space with those big jackhammers. Lots of fun.

  So how did you flop your gut over the jackhammer handles?  (it's been 30 years since I operated a jackhammer, but that's how we did it in the East Texas oilfields - and I wasn't even fat back then)

[AJ Dual]

This piece of concrete is about 2 feet across and at least two feet deep. Massive overkill when they poured it. It's also going underneath the neighbor's driveway a bit, so I don't know about trying to pull it out.

Oh damn... A cubic yard of concrete, depending on the mix and aggregate used, is going to be roughly 2-3000 lbs. 2x2x2' or roughly eight cubic feet of concrete is going to be about 700-900lbs. Plus dirt suction etc. I'm guessing that they probably did that to get rid of any leftover concrete, rather than figure out where to dispose of it.

Just rent another jackhammer to rescue the first one.  

[Monkeyleg]

So how did you flop your gut over the jackhammer handles?  (it's been 30 years since I operated a jackhammer, but that's how we did it in the East Texas oilfields - and I wasn't even fat back then)

No gut. Flat stomach. Tired arms.

[KD5NRH]

I don't suppose you have a couple 55 gallon drums of muriatic acid laying around, do you?

[280plus]

did you call the rental polace and tell them what happened. They may have ideas that we don't because it probably isn't the first time they've heard of this.

[French G.]

Tannerite, lots of it.

[Monkeyleg]

I'd thought about Tannerite yesterday for a split second. If the hole was far back in the yard away from the house and windows, it might have been an option and, while it would have taken out the jackhammer, it would have been fun to watch.

did you call the rental polace and tell them what happened. They may have ideas that we don't because it probably isn't the first time they've heard of this.

The rental place closed at 5 pm yesterday, before we ran into the stuck chisel problem. I called them right away this morning and then sent a guy over. It took him a minute to release the chisel.

The only problem is that it rained overnight (wasn't in the forecast) and the hole was filled with rain water, right up over the top of the jackhammer handle. I had the hole covered, but water still got in.

They're going to let it dry out and see if it works. They're cleaned them with pressure washers before with no problem, but they never had one immersed in water for hours. I may have bought myself an expensive lawn ornament.

Why do I start these projects? I was just going to get the gazebo into the yard and replace some boards on the fence. It's like the ground-up restoration on the Jaguar XKE. In the beginning I was just going to pull the cylinder head to replace some valve guide seals. I wound up tearing it completely apart and spent four years rebuilding the entire car.

[280plus]

The only problem is that it rained overnight (wasn't in the forecast) and the hole was filled with rain water, right up over the top of the jackhammer handle. I had the hole covered, but water still got in.
Damn,,,I'd say "that sucks" but you already know that. 

Keep yer finners crossed. If they dry it out real good before trying it it may still work. The words "heat gun" come to mind.

[roo_ster]

The only problem is that it rained overnight (wasn't in the forecast) and the hole was filled with rain water, right up over the top of the jackhammer handle. I had the hole covered, but water still got in.

Dang.  You sure you haven't been cursed by some backwoods Alabamian voodoo man?