Screen tubes are vital to the performance of adhesive anchors in base materials that are hollow or contain voids, such as hollow block and brick. The Simpson Strong-Tie® Opti-Mesh® screen tube provides the economical advantage of a plastic screen tube while providing performance comparable to steel screen tubes and better than competitive plastic screen tubes..
GALLERY: roll over images below to see larger image
Caution: Screen tubes are designed for a specific adhesive type. Epoxy screen tubes must be used with SET or ET-HP formulations and acrylic screen tubes must be used with AT adhesive. Do not use SET1.7KTA with screen tubes.
PRODUCT / APPLICATION INFORMATION
Acrylic Screen Tubes - Plastic
The photo on the left shows the Opti-Mesh® screen tube installed in a hollow CMU block. The extra collar of adhesive created by the open-mesh collar results in increased bearing area and higher load values. The typical screen tube shown on the right relies on the bond between the relatively small amount of adhesive in contact with the face shell of the block for its holding power.
The Simpson Strong-Tie Opti-Mesh screen (top) features formula specific mesh designed to control the flow of adhesive out of the screen. The result is uniform coverage of adhesive on the rod. The standard screen (bottom) utilizes mesh which allows adhesive to flow freely out of the screen when the rod is inserted. Too much adhesive is pushed out of the screen, leaving a large portion of the rod unbonded. This unbonded rod will pull out of the screen at a much lower load than a rod installed with an Opti-Mesh screen.
Drill holes to correct diameter and depth as specified in the load tables. When drilling into hollow concrete block or brick, the drill should be set to "rotation only" mode.
Once the hole is drilled properly, remove dust from the hole with oil-free compressed air. Dust left in the hole can reduce the adhesive's holding capacity.
Clean the hole with a nylon brush and blow out remaining dust.
Dispense a bead of adhesive off to the side to check for proper mixture (a uniform gray color)before filling the screen. Fill the screen completely, starting at the bottom to avoid air pockets.
Close the cap and insert the screen into the hole.
Anchor rods must be clean and oil free. Insert the rod, turning slowly until it contacts the bottom of the screen. Do not disturb during cure time.