When and How to Use Anchor Bolt Epoxy
If you want to be certain that an object is hung safely, use anchor bolt epoxy. No one wants to worry about the possibility of a fixture falling on a guest. Using epoxy to reinforce concrete and brick anchors insures that attachments are secure. Anchor bolts, or concrete screws, are adequate for connecting materials or artifacts to brick and concrete. If the fastener will be under an extraordinary amount of tension, you can add epoxy.
Step 1 – Determine the Need
If you use anchor bolts in hanging fixtures or artifacts, the weight of the items will determine whether or not you need anchor bolt epoxy. The adhesive improves the strength by 12 percent, when used with bolts of 3/8 inch or larger. You may be fastening a heavy wall hanging or overhead light that needs to be especially secure. The epoxy can improve both tension, or outward pull, and sheer, which is the downward force. Epoxy can also be used where holes for the anchors are larger than the fastener’s specifications. It can provide sufficient bonding when you have used an oversize bit.
Step 2 – Choose the Fastener
You will see little difference in using anchors under 3/8 inch, with or without epoxy. The bolts themselves are not strong enough to withhold excess weight. They will falter before pulling out of the wall. The size of your job will determine the diameter. Anchor bolt epoxy is also an effective adhesive for threaded rod, J-bolts, rebar and other materials that might be inserted into masonry and hardened concrete. The anchors you should use with epoxy are:
- 3/8 ½ inch
- 5/8 ¾ inch
- 7/8 inch
- 1 inch
Step 3 – Prepare the Surface
Drill a hole in the concrete or masonry the size of the anchor bolt you plan to install. Minimum embedment depth depends on the thickness of the material being attached. Sleeve anchors should be embedded at least 1 ¼ inch and up to 2 inches for ¾ inch bolts. Use a hammer drill and masonry bit to create the holes. Clean all dust and concrete chips from the holes.
Step 4 – Installing the Anchor
Anchor bolt epoxy is a compound of a resin and a catalyst. For large jobs, some brands of epoxy are packaged in two cartridges that can be applied with a dispenser much like a caulk gun. Read the instructions carefully for the epoxy you use. The two ingredients must be mixed exactly to specifications. Press the epoxy into the drilled hole after insuring it is well mixed. You have about 5 minutes before the adhesive hardens. Fasten the nut and washer to the anchor bolt, but do not let them touch the epoxy. Twist the nut around several times in the hole to allow the epoxy to spread. Allow the anchor bolt epoxy to harden before tightening the bolt.