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Spinning concrete anchor

Kaizen

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Can’t find this answer for some reason. Installing two post lift drilling 3/4 inch anchors in my 6inch 4k concrete. Two are spinning and before I keep messing with them thought I’d reach out
One is just spinning. Have three threads above the nut. Should I try and just put vice grip on it and use open end wrench? Or weld something to it?
Other one my fault. Out of habit I backed the nut off so I was hitting the nut not the bolt. So now the nut is stuck. Doubt I can get under it.
Should I try epoxy hopefully will bind the nut to the metal baseplate?
Or just try and put a crowbar on them and pull? I did use a new but and sds as well as blew out the holes. Did not drill through all the way so hammering isn’t an option.


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PoorOwner

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Is it spinning without much force or are you trying to reach a final torque?
do you know if the wedge has expanded yet?
 
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mrobins297aaa

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I'm not sure how pulling them out is going to help you?
wouldn't you have the same problem with a new anchor? at least on the one.
I would definitely try the vise grips on the one or even weld something on the bolt.
I think if you can get it to catch a little bit it may stop spinning.
On the one you damaged the threads on the nut.......weld something on the top of the bolt.
If all else fails you could just weld a clip on to the base plate and drill a new anchor, I know it wouldn't look so good but after you've used the lift a few hundred times you won't even notice it.
 
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PoorOwner

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You could hold it with a vise grip then, you should feel it expand and stop spinning once it meets the base plate.

Hard to believe you have messed up the thread hammering on the nut on one of them, you can try hold with a vise grip, back the nut and see what the thread looks like.

Usually I have to tap hard for the anchor to sit in the hole, it would not spin, but you can kind of feel the torque progressing quickly as the wedge expand..

good luck.
 
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Kaizen

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Ok thanks. So no magic solution I guess. I will have at it in the morning. They are down four inches so if I can get them to bite a little it will be fine


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Jlbc212

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Sometimes all it takes is a little pressure exerted between the base of the nut (or washer) and the top of the lift's base plate to get the wedge to anchor sufficiently so the anchor won't turn as you tighten the nut. Another alternative would be to cut the nut off, run a file, or a small Dremel grinding wheel or a die to repair the damaged anchor bolt threads.
 

FANTM58

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Maybe take a mini grinder with a slicer disk ( thinn ) and cut a groove in the head for a screw driver
Then use an open end wrench ????
 

matt_i

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I'd just use a vise grip as suggested on the unthreaded pilot end of the stud. Use an open end or box wrench to get the wedge started.

If it pulls all the way out its time for an epoxied stud imo.
 
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Kaizen

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Well that sucked. Figured with the importance I better go get a new set of vice grips. Also needed a wrench as largest I had was 1 inch. First one no problem. Vice grips worked great. Second one where I mashed the threads took a lot. Started with micro file to try and fix the thread. Then went to large file to remove the broken sections of thread. Then grinder to take off all threads to that point. Then welded a bolt on top and was able to get it to thread down. Seems to be grabbing. Will see when I torque it.
3b968babd2691c4ec0101fb901cd4b12.jpg

These anchors have a smaller top with no threads so I figured after this first error you are supposed to actually hit the bolt only. It does mushroom out but these won’t ever come out.
Thanks for the guidance



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matt_i

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That looks very wrong to me, just based on the length alone. Did that much of the stud pull out from the initial tap-down? (iow the nut started its life completely at the top of it)

Just guessing here, but if you started with a 6-7" anchor and it looks like about 3" is already pulled out trying to gage via the 3/4" major diameter....thats insufficient "grip" in my estimation. Keep in mind the wedge anchor is trying to break an inverted pyramid out of the slab as its stressed under tension so the thicker the concrete and the longer the anchor, the more load it will take to enact that theoretical failure. Too shalllow and not much pullout strength.

If you have a thin cutoff disk you can slice thru that anchor and then use a regular file to chamfer the top edge and remove the ragged edge.
 

joey1320

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That looks very wrong to me, just based on the length alone. Did that much of the stud pull out from the initial tap-down? (iow the nut started its life completely at the top of it)

OP welded a bolt to the old stud during the repair.
 

Lucid Moments

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For future planning purposes since I am going to be buying a lift in the next few months. Do most people prefer the wedge anchors, or are epoxy anchors better?
 

oledude1952

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I have always favored sleeve anchors over wedge, as their expansion cones are taller, meaning more metal digging in to the walls of the hole bored.

And for heavy loads that will have vertical or side movements being held down by anchors, I like epoxied in "all thread rod" over expansion anchors.

My sketch here sort of shows my interpretation of what I think, is going on with expansion anchors vs. epoxy. I may be wrong here though and JMO.
 
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gmwelder86

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Wedge are fine for a lift install epoxy is generally used in high vibration or old concrete that may not take the expansion force of a wedge anchor.
 
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Kaizen

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For future planning purposes since I am going to be buying a lift in the next few months. Do most people prefer the wedge anchors, or are epoxy anchors better?



My atlas came with these fasteners included. I liked having the manufacturer supply their spec bolts. My problems are my own doing. Get a good sds drill. Hd has some for under 200.


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gmtech

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My atlas came with these fasteners included. I liked having the manufacturer supply their spec bolts. My problems are my own doing. Get a good sds drill. Hd has some for under 200.


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Harbor freight has them for $69 Lol. Just installed my lift last weekend.

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BD1

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Drop in anchors are great and you have a bolt head exposed instead of a nut and threads.
 
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rlitman

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I have always favored sleeve anchors over wedge, as their expansion cones are taller, meaning more metal digging in to the walls of the hole bored.

And for heavy loads that will have vertical or side movements being held down by anchors, I like epoxied in "all thread rod" over expansion anchors.

My sketch here sort of shows my interpretation of what I think, is going on with expansion anchors vs. epoxy. I may be wrong here though and JMO.

I'm not so comfortable with your interpretation of your diagram. As I see it, the wedge, pulls from the far side of the concrete like a carriage bolt would, whereas the epoxy pulls over the whole length of the hole like an ordinary screw. If tension is all you care about, the former is stronger. And epoxy isn't all it's cracked up to be:

https://en.wikipedia.org/wiki/Big_Dig_ceiling_collapse
 

CJseven

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Harbor freight has them for $69 Lol. Just installed my lift last weekend.

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Did you use the harbor Freight Bits or did you buy a different brand? I’ve heard a few times that some bits made the holes slightly larger than they were suppose to be for the anchors.
 

gmtech

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Did you use the harbor Freight Bits or did you buy a different brand? I’ve heard a few times that some bits made the holes slightly larger than they were suppose to be for the anchors.
I bought the $97 10 amp drill with a coupon for $69. I couldn't make myself buy the HF bits. I bought a Bosch that was suitable for rebar at Lowe's for $30. Drilled all 12 holes thru 7" of concrete like butter.

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oledude1952

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I'm not so comfortable with your interpretation of your diagram. As I see it, the wedge, pulls from the far side of the concrete like a carriage bolt would, whereas the epoxy pulls over the whole length of the hole like an ordinary screw. If tension is all you care about, the former is stronger. And epoxy isn't all it's cracked up to be:

https://en.wikipedia.org/wiki/Big_Dig_ceiling_collapse

My sketch and reply here is really taking the anchoring topic to the extreme, but I have too much time on my hands now while being retired. So I find these topics fun now. :)

Any time a load is being supported entirely from the structure ABOVE it like in a parking structure, those anchoring devices have to be approved by an engineer/or the architects .

So somewhere in the linked WIKI article "fail" stating there was a epoxy anchoring system failure, IMO either the engineer/architect or structural inspector dropped the ball.

No anchoring system can be ever be fool proof IF, it is being used to support a load weight or load movement, that it was NOT designed to be able to do.

And there is always, the possibility of the improper installations of an anchoring device by the workers doing it, even WHEN all the engineering/inspection criteria HAS been met.

I am a bit confused here to the blue text in your reply above with the mention of a carriage bolt resemblance, to a wedge anchor in regards to holding power ?



My comparison drawn in my sketch shows the vertical lift movement on the anchor bolt like from a car lift frame. (the OP for this topic)

On the left in my sketch, I see the wedge anchor expansion cone SLOWLY over a long period of time while staying centered in the hole, as being pulled VERY SLOWLY upward by the lift frames vibrations. This action will SLOWLY degrade the side walls of the drilled hole where the wedge anchors expansion cone is spread against them.

Then over time, as the expansion cone is SLOWLY pulled upward, it will then bite in to undamaged, fresh sidewall concrete while locking the anchor bolt securely again in the hole .

Which then requires re-torqueing the anchoring nut/washer down, to keep the load secured down tightly. Not a bad thing to do if needed. It just may have to be done randomly over time, as the wedge anchor bolt slowly protrudes higher and higher out of the concrete, as it is pulled upwards over time. The amount the bolt pulls upwards, depends on how much movement the frame gets. Maybe none.

The epoxied all thread rod in comparison, has the same upward lifting force on it, that the wedge anchor bolt has on it. But the load being secured by the epoxied bolt, will have to overcome the TOTAL resistance of ALL the epoxy that is bonded in to the bolts threads and against the holes side walls, for the full height of the hole, and for the total circumference of the hole.

So if one takes the TOTAL "holding" capability of the wedge anchor bolt/expansion cone that is only about .500 in. tall, and compare it to the epoxied all thread rod....where the epoxy has much more actual surface to surface contact of resistance to movement, than the .500 in. tall wedge anchor with its thin expanding metal cone does.

I see it happening this way IMO, maybe it does not though. With loads that can move around over time, I like epoxied all thread rod being installed properly and per all instructions...in lieu of wedge anchors.

At least if the epoxy fails and the bolt starts pulling out, the same size hole can be drilled in the floor again, then a wedge/sleeve anchor used. But if the wedge anchor fails, a larger hole will have to be drilled to accommodate a larger bolt diameter wedge/sleeve anchor. Which will then mean, the steel anchoring plate holes will have to be enlarged also for the new anchor bolt to fit through. I agree, too much thinking going on here. Cheers... :beer: JMO though.
 
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rlitman

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...I am a bit confused here to the blue text in your reply above with the mention of a carriage bolt resemblance, to a wedge anchor in regards to holding power ?

My comparison drawn in my sketch shows the vertical lift movement on the anchor bolt like from a car lift frame. (the OP for this topic)

On the left in my sketch, I see the wedge anchor expansion cone SLOWLY over a long period of time while staying centered in the hole, as being pulled VERY SLOWLY upward by the lift frames vibrations...

If the wedge anchor has lifted at all from "vibrations", it WILL fail, and is beyond it's design.

My point is that the wedge anchor is pulling on the underside of the concrete, placing the concrete in compression across it's thickest point, whereas the epoxy anchor will be lifting partly from the top of the concrete, placing some of the concrete in tension.
 

CJseven

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I bought the $97 10 amp drill with a coupon for $69. I couldn't make myself buy the HF bits. I bought a Bosch that was suitable for rebar at Lowe's for $30. Drilled all 12 holes thru 7" of concrete like butter.

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I have one of there rotary hammers and a bit set, but have only used the bits a couple of times to anchor a swing set and a few yard type stuff, but for my lift I figured it would be best If I bought a good name brand bit.
 
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Kaizen

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I unfortunately have to rehash this thread.
I figured out i had the damn arms on backwards so fixed that and decided to torque the bolts again since its been a few months since i last ran it.
The one that i had an issue with above that i KNOW torqued perfect before is spinning again. This time almost out of the hole so that the anchor is wobbling when moved by hand. But just using a crowbar it won't pop out.
Another one that was perfect before is spinning now AND even though it never hit torque i stripped the threads on the anchor. The first one is on a corner and this one is one in from the opposite corner.

I fought with these for hours yesterday. Tried loosening the nuts and hammering them back down. While they both went down no problem the stripped one will continue spinning unless i use vice grips and an open ended wrench. when i do this it will stop moving but if i put the torch wrench on it then spins.
The other problem child just works its way up out of the hole to the point i described above. Both are under some tension when i'm wrenching them. In other words they do not just spin freely.
Called the distributor tech support and they suggested working them out again and then put epoxy on them, hammer down, and pray. Also just told me to go to home depot and get some. I obviously want the best in this situation so what should i be using?
Any other ideas on getting the wobbly one out? i'm guessing the sleeve has to be half inch from top. as its on the corner i'd love to get it out and get an actual epoxy anchor for that hole.
Thought they would say just drill through the base and stick another in but they said you shouldn't grill within 6 inches of a hole or crack.
I so should have just spent the money on epoxy anchors in the first place.
 

PoorOwner

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You will have to extract or drill out the bad ones and put epoxy anchors down.

The epoxy anchor requires a little bigger hole so as long as you don't pull out a chunk of concrete with the bad anchor it's no big deal.

Sometimes people will say pound them into the earth if it was drilled through at first.
 
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Kaizen

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You will have to extract or drill out the bad ones and put epoxy anchors down.

The epoxy anchor requires a little bigger hole so as long as you don't pull out a chunk of concrete with the bad anchor it's no big deal.

Sometimes people will say pound them into the earth if it was drilled through at first.



How would I drill it? I have to think that would be pretty difficult? I have one left and think the threads are too bad to use it.

I got two out as they were moving up and down. I cut a nut in half and put it under the washers and they came out. Both had the sleeve ripped off. Starting to think the directions have the wrong torque numbers.
925d2f5c77e757a8292716d5d4f50a20.jpg


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Kaizen

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Definitely ordering hilti fasteners. Going to put a borescope down to see what is going on. Seems strange 3 in a row let go. This is 4k 6 inch concrete. When I drilled the holes it looked perfect. Like a hole through granite.
Question still remains in the one left. Drill through the top of the bolt all the way down with increasing drill sizes? Or perhaps a thin one down one side to try and break the sleeve?


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PoorOwner

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should be able to drill out the sleeve progressively, and then go back to concrete bits for your final size for your epoxy anchor

150 seems high to me also. Usually see other lifts going about 95-105 ft lbs
 
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Kaizen

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should be able to drill out the sleeve progressively, and then go back to concrete bits for your final size for your epoxy anchor

150 seems high to me also. Usually see other lifts going about 95-105 ft lbs



Think I will do more like 120-130. I confirmed with distributor on amount.
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Razor128

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Adding to an old thread but I Just had this problem. I mashed the threads on the first one I did. I had a small amount of room under the washer, see pics.
Basically a pitman arm puller and a 2 jaw puller together got it out.
 

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Kaizen

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Adding to an old thread but I Just had this problem. I mashed the threads on the first one I did. I had a small amount of room under the washer, see pics.
Basically a pitman arm puller and a 2 jaw puller together got it out.


And to think I had them ten feet away the whole time. Grrrr. Good idea.


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