Application Instructions

Primer
Small exterior joints of less than ½” do not need a primer. Large joints with the substrate prepared via shot-blasting or sand blasting may not require a primer. For large moving joints a primer may be used. Use ASTC 6012-2F Epoxy or  7001 Polyurethane Primer . Prime 1-2 hours before application of the 3246. For best bonding results apply the joint product as soon as possible over the primer when the solvent in the primer has flashed. All moving joints require a primer before application of the 3246. Prime approximately one hour before application of the 3246. For best bonding results apply the joint product as soon as possible over the primer. See data sheets on above primers.

Application
Use a 1:1 positive displacement (cylinder) application machine or plural component pump such as the US Saws Model SX2000. Pre-condition 3246; Make sure the product is >72°F before beginning the machine application. Warm the product in the containers as needed to proper working temperature for this product. Use ONLY the ASTC recommended static mixing units for this product.  When using Duplex Cartridges of the 3246 PenJoint, keep cartridges warm and follow all application instructions for cartridge use.  You will need a Manual or Pneumatic Cartridge Gun to properly dispense the twin cartridges.

Preparation
Concrete must have a minimum 28 day cure prior to application. Use a dry diamond saw, saw/abrade both sides of the joint walls. Assure that the joint is properly abraded and cleaned to full depth of the product fill area. Clean saw cut joints with a wash-down of alcohol/water mix or other fast flash solvent to remove dust prior to product application. The concrete surface must be dry. Remove any curing agent, form release materials, oils, wax, moisture or any material that may effect bonding. Clean, vacuum and wash to remove dust from the walls of the joint.

Filling
Fill the joint from the bottom of the joint up. Fill as suggested above; fill depth and fill to below grade. The product is self- leveling and quick to set, avoid overfilling.  Always mix the part B before using.

After the 3246 has set, about 10 minutes, a simple dusting using corn starch removes the remaining surface tack eliminating the potential of environmental dust, insects, etc. sticking to the surface as well as providing a smooth color stable finish.  The dusted surface can be touched in just a few minutes allowing traffic into adjacent areas in 30 minutes or less.  Excess dust is removed using a blast of compressed air, a standard leaf blower or a broom. The result is a clean and nicely finished expansion joint that is ready for service.

Bond Breaker
A bond breaker is often used at the bottom of an expansion joint to allow for greater movement of the product filling the joint. Use a bond breaker on deep joint fills as needed.

Joint Size and Movements:

Expansion joints should be designed with a maximum of +/- 25% movement. The overall movement of a joint should be measured at the temperatures extremes that are normal for the structure.  Measure the opening of the joint at the coldest temperature and at the highest temperature and multiply by 4. If a joint opens and closes 1/4 inch the joint width should be 1 inch and the fill depth should also be approximately ½” to 1 inch with the backer rod placed at this depth.

Depth:
Minimum depth is normally about half the open width of the joint to equal the depth over backer rod. Areas of higher movement, standing water and deicing chemicals should have joint depth of ½ the width and up to 1 to 1.5 inches depth over a backer rod.
Structures such as bridges, airfields or parking structures that are exposed to wide thermal cycle swings and a high movement potential that may exert excessive compression and expansion (pulling) forces on the joint material should be filled when they are “cool” and open. The configuration of the backer rod should be round allowing for the added depth on the sides of the fill.

Minimum Depth Airfields:

Shallow fill applications have a greater potential for loss of adhesive bond and damage when snow removal equipment is used. Moving joints may be filled slightly greater than the half the width as determined by the project engineer. A primer may be required.

Below Finished Grade
Keep the installation of the product slightly below the finished surface grade. Install the product when the joint area is cool and the joint is open.

Important
Monitor The Static Mixing Wand, During The Application And Change Static Mixers When Product Build-Up Is Observed. Failure To Do The Above May Result In Improper Product Mixing.

LIMITATIONS

• Top coat the surface of the 3246 not more than 1 hour after application in joints on surfaces that will have a finish coat
• Do not use on wet surfaces or expose part A to moisture.  Part A is moisture sensitive, keep away from compressed air units that may dispense moisture near the part A, avoid exposing the pail/container to humidity. Observe appearance of part A in humid conditions.
• Store out of direct sunlight, store ten gallon kits on wood pallets at room temperature.
• Warm or pre-condition product kits on pallets before using in cool conditions below 70F.
• 3246 Polyurea exhibits good chemical resistance to motor pool fluids, aviation fluids, i.e. hydraulic fluid, diesel fuel and JP4 and cleaning solutions for short periods of time. To maintain proper joint integrity clean up chemical spills soon.
• Submersion of product or continued water ponding over product - may result in a low skid resistance condition, hazardous working condition or slip hazard. Chemicals, oils, soaps etc. should be removed from the surface as a normal part of cleaning and maintenance.