Epoxy or wedge anchors ?

[mad1stgen]

Well,
after using the maxjax for 7 months, I decided to cut out and repour 4x4 concrete pads in order to locate the columns better in my garage. Originally I used the wedge anchors provided with the lift.

Now, I have to buy a new set of anchors to re-install the lift on the new concrete, and was wondering if I should go with the wedge anchors (as supplied with maxjax):

PD-58 http://www.drillspot.com/products/43499/Wej-IT_PD-58_Drop-IN_Anchor

or the epoxy specific anchors:

PS2-58 http://www.drillspot.com/products/128424/Wej-IT_PS2-58_Epoxy_Grip_Anchor

that is also available from GES as a kit for $109

http://www.gesusa.com/Epoxy-Grip-Anchor-Bolt-Kit-p/100121.htm.

I really had no issues setting the wedge anchors in the old floor, but after the 7 months I noticed some cracking of the concrete (mainly due to proximity of the control cracks although still within 7" spec, and concrete being only 5" deep at most) and pulling up of the sleeves. I don't want to deal with this again. I am leaning towards the epoxy kit myself ... Thanks All !

 

[mad1stgen]

Few more pictures for reference

 

[petee_c]

On saturday I just installed the maxjax in 3x4x1' footings I poured in my floor. 9 outta 10 anchors went fine. 1 didnt seat quite right and I was contemplating how to fix it. I was planning to try to pull it out but it ended up tightening up about 3/16" above the surface of the floor. I ended up grinding off the little bit of stub that was sticking up. I had got a small tube of epoxy and was going to install another anchor with epoxy as backup. However this anchor is now stuck and usable

Given the problems I had with the 1 anchor I would contemplate using a epoxy one if I had the choice.

 

[trbomax]

In the old shop I installed my Rotary with parabolts on a 4" slab that was 20yrs old at the time. That was close to 20 yrs ago and its still working just fine. my son uses it now. I'm sure that the slab was nothing special because it was just the single car garage that came with the house,I built the shop around and over the old garage with a 6" steel reinforced floor but put the lift just inside the door,which was the original garage. Even today there are no cracks in the original floor.Maybe the old timers that did it knew something we dont.

 

[wssix99]

You should install the lift with anchors supplied by or specified by the lift manufacturer. Epoxies have different resistances to various forces and may not hold as strong as a regular bolt in a given application. (For example, you'll see disclaimers on many epoxies that they are not to be used to support items overhead.)

 

[mad1stgen]

Well, it was Wej-IT themselves who suggested the epoxy anchors in place of the wedge ones provided with the lift. Moreover, the GES is a distributor for Danmar/Bendpak, and they sell the epoxy anchor kit. Also, the specs for the epoxy anchors surpass the wedge anchor specs by far. So there is no question of whether they will work in this situation. It's more of a question whether they are truly a better solution to this problem. I'd think that with the portability of this lift an epoxy anchor would work better in a situation when the column is unbolted frequently. Each time you torque the bolts in wedge anchors they are being pulled up a hair. That shouldn't be the case with the epoxy ones ?

 

[rlitman]

You should install the lift with anchors supplied by or specified by the lift manufacturer. Epoxies have different resistances to various forces and may not hold as strong as a regular bolt in a given application. (For example, you'll see disclaimers on many epoxies that they are not to be used to support items overhead.)

Epoxy anchors "properly" installed, are FAR stronger against being directly pulled out, than wedge anchors, against a dynamic load.
There are two catches to this though.

1) Their proper installation requires cleaning the hole (blowing it out with air may be ok; maybe you need to use a brush; either way, if you're using the adhesive, you MUST follow the manufacturer's instructions to the letter).

2) The epoxy is subject to creep. Under a static load, the epoxy will stretch over time, and in an overhead load, if improperly engineered, this can cause a failure (it caused fatalities in the "Big Dig"; I suggest you look that up).
Aside from overhead applications, if the nuts required a specific torque to preload the fastener, the preload could be lost over time due to creep. I don't think this is a big deal with a lift, but I could be wrong.

 

[wssix99]

Well, it was Wej-IT themselves who suggested the epoxy anchors in place of the wedge ones provided with the lift. Moreover, the GES is a distributor for Danmar/Bendpak, and they sell the epoxy anchor kit. Also, the specs for the epoxy anchors surpass the wedge anchor specs by far. So there is no question of whether they will work in this situation. It's more of a question whether they are truly a better solution to this problem. I'd think that with the portability of this lift an epoxy anchor would work better in a situation when the column is unbolted frequently. Each time you torque the bolts in wedge anchors they are being pulled up a hair. That shouldn't be the case with the epoxy ones ?

If the epoxy kits are supplied for lifts, then they should be fine for your application. I think your line of thought is correct in that they will hold up better for repeated use. rlitman has some good comments as well.

As long as the anchors aren't chewing up the concrete, the traditional anchors should also be just fine. (Your 4X4 concrete slabs will probably rip out before the bolts do. (With a little linear algebra, you can calculate that-but linear algebra is no fun... Without seeing the bolt pattern, I'd guess the maximum pulling force on a bolt would be far less than a 10th of the load you are lifting.)

If you ever want to remove the anchors in the future, (to move placement of the lift, etc.) the epoxied ones could be a PITA to get out. Just another thing to consider.

 

[rlitman]

If you ever want to remove the anchors in the future, (to move placement of the lift, etc.) the epoxied ones could be a PITA to get out. Just another thing to consider.

Now that's a good point! Ordinarily, to "erase" wedge bolts, I use an angle grinder to cut them flush, and then drive them down with a persuading hammer and chisel. Once they're under the surface, you can fill the hole with concrete patch. With glue in bolts, I would think that once you cut it flush, there's not much more you can do.

 

[whejdak]

I installed 5 wej-it PD58's and they worked perfectly. Then I went to the other post installed 5 more and they would not grab. So now I'm going to move the post and install the 5 new pd58's but I'm going to apply epoxy before inserting the anchor bolts. The PD58's are sealed from the outside and no epoxy should get into the treads. But I'm going to have to get the anchors set (wedged) before the epoxy sets.

 

[jhelrey]

Push down as you tighten it up...

 

[noboD]

I installed 5 wej-it PD58's and they worked perfectly. Then I went to the other post installed 5 more and they would not grab. So now I'm going to move the post and install the 5 new pd58's but I'm going to apply epoxy before inserting the anchor bolts. The PD58's are sealed from the outside and no epoxy should get into the treads. But I'm going to have to get the anchors set (wedged) before the epoxy sets.

Sounds like you didnt' have all the dirt cleaned out of the hole before you pulled your anchor. We use both wedge and epoxy anchors at work. Both should do a good job for you.

 

[Buckled]

Epoxy anchors "properly" installed, are FAR stronger against being directly pulled out, than wedge anchors, against a dynamic load.
There are two catches to this though.

1) Their proper installation requires cleaning the hole (blowing it out with air may be ok; maybe you need to use a brush; either way, if you're using the adhesive, you MUST follow the manufacturer's instructions to the letter).

2) The epoxy is subject to creep. Under a static load, the epoxy will stretch over time, and in an overhead load, if improperly engineered, this can cause a failure (it caused fatalities in the "Big Dig"; I suggest you look that up).
Aside from overhead applications, if the nuts required a specific torque to preload the fastener, the preload could be lost over time due to creep. I don't think this is a big deal with a lift, but I could be wrong.

Creep can be an issue when dealing with epoxy anchors. However, it usually effects very fast curing epoxy. Go with a reputable, slow cure epoxy and you'll be fine. The loads at the big dig were far greater than you'll experience with your lift.

Brushing the hole and using compressed air to blow the dust out is the best way to clean the hole.

 

[mad1stgen]

Lots of good info guys ... thanks a lot !!!

I ordered the epoxy anchor kit from GES. Rudy was a big help, and got the kit for $113 shipped. It contains 10 PS2-58 Wej-It anchors, and two tubes of EAC8 Epoxy. It should be here in time for next weekend re-install

 

[oldwino]

as a general rule...wedge anchors are fine if no movement or vibration will be encountered. otherwise, epoxy is the way to go