Epoxy Anchor installation

[lemmy999]

I have had one of my wedge anchors for my 2 post lift pull up above the concrete floor. So I hammered it down in to the ground below the slab. My slab is 5" thick and under the slab is some gravel and below that just dirt. I know I need to clean out the holes thoroughly using a brush and compressed air, but the walls of the holes seem relatively smooth. Will the epoxy bond with this or do I need to rough up the sides of the hole in the concrete somehow? I assume it isn't since it isn't in the instructions, but I have little experience with using epoxy with concrete.

Another question I have is how do you keep the epoxy off of the threads? I will put a bolt in the anchor and insert it into the hole that is 1/2 filled with epoxy. But I assume some epoxy will come out the top and I would like to keep this off of the threads of the bolt and of course I really don't want it to get down in to the threads of the anchor.

Is it best to have the top of the anchor level with the concrete floor or should it be slightly recessed like the wedge anchors?

 

[Jeffh40]

Engineering and technical data from Hilti in the link.

https://www.hilti.com/medias/sys_ma...12999657502/ASSET_DOC_LOC_1544930_APC_RAW.pdf

The epoxy will bond with the hole in the concrete just fine but it will have to be clean. Brush it out and blow compressed air in to make sure it is clean.

Inject the correct amount of epoxy in the hole (enough to fill the hole once the rod is shoved in). And then push the rod in the hole.

More information is on Hilti's website.

 

[matt_i]

The epoxy will bond to the finish no matter what.

The key is to remove the dust.

I use a shop vac and a metal pipette that will reach the bottom of the drilled hole. Blow and vac until no more dust appears. Then brush. Then blow and vac. Several times.

I like to use a nitrile glove and coat the threaded rod with some of the epoxy before gunning it into the hole. Twist the rod as you install it otherwise if you push it straight down there will be a big pop of air and epoxy will spit out all over that you really need in the hole. A little should spill out of the top at the end. If its excessive just wipe with paper towel (etc) and then wire brush it off the threads.

The top of the threaded rod has to account for the baseplate, the washer(s) and the nut plus a few more threads, and reach the bottom of the hole. Good to chamfer the stud on the top so the nut will start easily.

I like to buy B7 threaded rod from McMaster Carr since it approximates a Grade 5 bolt. I drill 1/16 to 1/8" oversize depending on the size of the fastener. I also like to use Sika Anchorfix 2 which you can buy at the Home D.

Caveat: I've not installed epoxy anchors for a lift, but have put in epoxy anchors for columns, small bridge crane systems and high-confidence systems like jib cranes which depend entirely on the strength of the epoxy.

 

[AZ Pete]

Epoxy will not stick to wax. Coat the threads that will be above floor level with paste wax. Do your best to keep the epoxy off of the threads, but it will not adhere to the waxed surface.

 

[thecj3man]

If you drill all the way through the slab do you have to seal the bottom of the hole? What keeps the epoxy from pushing out the bottom when you stick the anchor in the hole? I have debated epoxying the lift anchors if I install another lift. I drilled all the way through when I put in the expanding anchors for my first lift.

 

[lemmy999]

If you drill all the way through the slab do you have to seal the bottom of the hole? What keeps the epoxy from pushing out the bottom when you stick the anchor in the hole? I have debated epoxying the lift anchors if I install another lift. I drilled all the way through when I put in the expanding anchors for my first lift.

There has been a lot of discussion on this and I have heard many different comments/ideas:

1) stuffing coffee filters in the bottom of the hole to keep the epoxy from pushing out (seems to be one of the most popular)

2) stuffing other stuff like rolled up cardboard, or even foam in to the bottom of the hole

3) one guy suggested using a thin cementitious grout like SikaGrout 212 and pouring it in the hole and re-drilling. I thought about doing this, but I wouldn't want it to come up above the bottom of the existing hole because I don't know how it would affect the strength of the epoxy bond with the concrete

4) some say as long as you don't have a big void under the slab (I have dirt and tightly packed gravel) then the epoxy is thick enough not to push out.

I haven't really decided what I will do. This stuff sets up so quickly that I am a bit nervous that I will get in the middle of installing it and come across some problem and it will be too late to do something about it.

 

[lemmy999]

The epoxy will bond to the finish no matter what.

The key is to remove the dust.

I use a shop vac and a metal pipette that will reach the bottom of the drilled hole. Blow and vac until no more dust appears. Then brush. Then blow and vac. Several times.

I like to use a nitrile glove and coat the threaded rod with some of the epoxy before gunning it into the hole. Twist the rod as you install it otherwise if you push it straight down there will be a big pop of air and epoxy will spit out all over that you really need in the hole. A little should spill out of the top at the end. If its excessive just wipe with paper towel (etc) and then wire brush it off the threads.

The top of the threaded rod has to account for the baseplate, the washer(s) and the nut plus a few more threads, and reach the bottom of the hole. Good to chamfer the stud on the top so the nut will start easily.

I like to buy B7 threaded rod from McMaster Carr since it approximates a Grade 5 bolt. I drill 1/16 to 1/8" oversize depending on the size of the fastener. I also like to use Sika Anchorfix 2 which you can buy at the Home D.

Caveat: I've not installed epoxy anchors for a lift, but have put in epoxy anchors for columns, small bridge crane systems and high-confidence systems like jib cranes which depend entirely on the strength of the epoxy.

Thanks for the info. The anchors I am installing have female threads. So the anchor goes in the hole and is flush (or nearly flush) with the garage floor. Then a bolt will screw down through the base plate and in to the anchor that is secured in the floor.

 

[matt_i]

Thanks for the info. The anchors I am installing have female threads. So the anchor goes in the hole and is flush (or nearly flush) with the garage floor. Then a bolt will screw down through the base plate and in to the anchor that is secured in the floor.

You're worrying me a little. If its a drop-in expansion anchor with relief cuts at the bottom and a little metal plug that you rap down to set the expansion I wouldn't use it, my opinion is that its light-duty only.

I have seen others with many parallel, square-bottomed circumferential grooves in the OD, and several inches long. Possibly custom made. Those would be much better.

The threaded stud is a proven solution.

 

[lemmy999]

You're worrying me a little. If its a drop-in expansion anchor with relief cuts at the bottom and a little metal plug that you rap down to set the expansion I wouldn't use it, my opinion is that its light-duty only.

I have seen others with many parallel, square-bottomed circumferential grooves in the OD, and several inches long. Possibly custom made. Those would be much better.

The threaded stud is a proven solution.

It is these POWER-Sert Epoxy anchors:

http://www.toggler.com/wejit/power_sert.html

 

[mcbane]

Epoxy requires special inspection these days because improper installation can result in low strength anchors, and improper installation is common. You need to clean out the drill hole as mentioned above. And you need to inject epoxy at the BOTTOM of the hole. If trapped air is causing epoxy to blow out of the hole as you push in the anchor the installation, in technical terms, is FUBAR. Anyone who has seen trapped air cause epoxy to spit out has been doing it wrong. For female thread anchors, the safest course is to grease up a bolt and thread it into the anchor before you install the anchor.


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[matt_i]

It is these POWER-Sert Epoxy anchors:

http://www.toggler.com/wejit/power_sert.html

I liked it until I read "machine lathed". Maybe they meant "lathe machined" or "turned"

Those seem good.

If you precoat the rod working it into the threads to ensure that there's no gaps down in the thread roots there's going to be an air pocket unless a person is wasting the epoxy to fill it entirely to the top. Wrong? Depends if a person is satisfied the epoxy is going to fully fill the threadform on its own.

 

[lemmy999]

I liked it until I read "machine lathed". Maybe they meant "lathe machined" or "turned"

Those seem good.

If you precoat the rod working it into the threads to ensure that there's no gaps down in the thread roots there's going to be an air pocket unless a person is wasting the epoxy to fill it entirely to the top. Wrong? Depends if a person is satisfied the epoxy is going to fully fill the threadform on its own.

Are you talking about coating the area (where I drew the red lines in the attached pic) with epoxy, then filling the hole with epoxy then inserting the anchor in the hole?

 

[joes169]

Put a bolt in the threads of the insert, cover it with painters tape, and pull off 10-15 minutes after you epoxy. Leave the bolt in for a few hours. As someone else mentioned above, be sure that the tip of the epoxy tube reaches the bottom of the hole, you don't want to trap any air. We always (inspected or not) use round wire brush cleaners on 1/8" NPT pipe to clean the holes, along with a long blow gun for compressed air, 3 times each minimum.

 

[Kaizen]

Those seem overly complicated. The two that I had to do I just used epoxy anchors with threads up through the hole. Hilti. Did have to drill the hole larger. 5/8 and original was half inch. I used a dewalt product that uses a normal caulking gun. Worked great


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[Jeffh40]

Those seem overly complicated. The two that I had to do I just used epoxy anchors with threads up through the hole. Hilti. Did have to drill the hole larger. 5/8 and original was half inch. I used a dewalt product that uses a normal caulking gun. Worked great


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Agreed. It is hard to beat a piece of all-thread and epoxy. That is a proven system that gets used every day on commercial construction projects all over the world.

We use mainly Hilti but Dewalt products are not bad, it is just hard to get the epoxy out if it is cold when using a standard caulking gun.

 

[A**holes Garage]

Wedge installation much different than epoxy anchoring.
As stated above, when using epoxy, you must oversize the hole
read manufacturers installation specs.

 

[Antoin]

Could you drill the hole out larger and go with the next size up wedge anchor?
It would do away with the need for epoxy.

 

[Kaizen]

Could you drill the hole out larger and go with the next size up wedge anchor?
It would do away with the need for epoxy.

But then if that fails he is stuck unless he drills the lift plate hole bigger. At half inch steel that would ****. Epoxy is a sure fire win as long as he does not torque wrong


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[Antoin]

But then if that fails he is stuck unless he drills the lift plate hole bigger. At half inch steel that would ****. Epoxy is a sure fire win as long as he does not torque wrong


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I agree with you.

Only a suggestion given that the original poster doesn't seem to have any/ much experience with epoxy and this is a way to avoid that.

As someone who has never used it myself it is probably the route I would take.

 

[lemmy999]

But then if that fails he is stuck unless he drills the lift plate hole bigger. At half inch steel that would ****. Epoxy is a sure fire win as long as he does not torque wrong


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What do you mean by "torque wrong"?

 

[Kaizen]

What do you mean by "torque wrong"?

My wedge anchors that came with the lift had to be torqued to 150ft pounds. Epoxy anchors only need like 20 or 30 if I remember correctly. Although it is much less it’s plenty clamping force to hold the lift. If you torque too much they will break loose. So read the epoxy directions


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[lemmy999]

My wedge anchors that came with the lift had to be torqued to 150ft pounds. Epoxy anchors only need like 20 or 30 if I remember correctly. Although it is much less it’s plenty clamping force to hold the lift. If you torque too much they will break loose. So read the epoxy directions


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Ok, thanks. That is what I thought you meant.

With my wedge anchors they specified 120 ft-lb I believe. I actually use a longer bolt and run it all the way to the bottom (maximum thread engagement) then I hold the bolt with a socket while I tighten a nut down against the base plate. It gives maximum thread engagement and also tightens to the proper torque without any twisting motion on the wedge anchor. I don't know if it is a good idea, but I saw someone else doing it and thought it sounded like a good idea. But I did have one anchor that came up just a bit over time.

 

[Jeffh40]

My wedge anchors that came with the lift had to be torqued to 150ft pounds. Epoxy anchors only need like 20 or 30 if I remember correctly. Although it is much less it’s plenty clamping force to hold the lift. If you torque too much they will break loose. So read the epoxy directions


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Properly installed epoxy anchors, the epoxy bond is stronger than the all-thread. You will break the rod before you pull them out.

 

[Kaizen]

Properly installed epoxy anchors, the epoxy bond is stronger than the all-thread. You will break the rod before you pull them out.

As I understand it from what I was told here is the clamping/pulling force is that way but torquing an epoxy anchor will break the epoxy free. Hell if I was going to take the chance.


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[matt_i]

I've tightened them very tight using long bars. Its solid as can be. If they break loose then its no-bueno, something is wrong.

 

[lemmy999]

The existing concrete slab was about 5" thick and the epoxy anchor needed a 6" hole. So I hammered the old wedge anchor down to about 6.5" below the surface of the floor. Then I mixed up some SikaGrout 212 and injected it through the existing hole using a cheap oil syringe that had a fairly big piece of hose on it. I injected just enough to come up just above the bottom of the hole then I let that set up for 3 days.

At this point the hole was about 4.5" deep so I drilled it out to 6" deep without using the hammer mode on the drill. This worked great for keeping the epoxy in the hole. I then injected the epoxy in the hole about 3" deep and twisted in the anchor and hammered it down to about 1/16" below the surface of the garage floor. Everything went well, but the AWF Wej-It epoxy sets up VERY fast. I think I would have trouble setting several anchors as I think it would get stiff in the nozzle before I could move on to the second anchor. The directions say it only has about a 4-5 minute working time at 70F and that time grows shorter at higher temperatures.

 

[mbrock]

These are a little more than coffee filters but handy if filters won't stay in place when installing epoxy anchors. https://www.whitecap.com/Simpson-Str...626-137ETS626/

Simpson Strong-Tie 5/8 x 6" 60 M Anchoring Screen Tube
Mfg#: ETS626 | SKU#: 137ETS626
Simpson Strong-Tie

 

[wondo]

Since the thread was already resurrected... My experience with using epoxy is with rebar in concrete repair where shooting too much in the hole isnt an issue if some oozes out. Any tricks to keep it off of the base plate when drilling through base plates on a lift and using epoxy anchors? I worry about getting any epoxy on the baseplate will make eventual removal impossible.

 

[watoga]

Since the thread was already resurrected... My experience with using epoxy is with rebar in concrete repair where shooting too much in the hole isnt an issue if some oozes out. Any tricks to keep it off of the base plate when drilling through base plates on a lift and using epoxy anchors? I worry about getting any epoxy on the baseplate will make eventual removal impossible.

Good question. The only person I know who used epoxy and wanted to avoid this issue: (1) drilled the holes with the lift columns in place; (2) slid the lift columns to the side so he could adequately clean (wire brush + vacuum multiple times) the holes; (3) applied the epoxy and studs to the holes and waited until they fully cured; and (4) 'walked' the lift columns back onto the epoxied bolt pattern before torquing down the nuts.

Maybe not the most elegant way of doing things, but he was worried about not being able to clean the drilled holes adequately if some dust was trapped around the lift columns, which might compromise the strength of the cured epoxy.

Cheers,
Dave

PS - if you decide to go down the epoxy route you should take some pictures and do a "how to"

 

[nadogail]

Thanks for sharing.