AU-1 Commercial Construction Sealant

Description

AU-1 is a highly elastic and extremely durable high-performance construction sealant. It is an aqueous-based urethane acrylic polymer and one of the first high performance sealants of its kind for the commercial building industry. The active ingredient in AU-1 is an Aqueous Polyurethane Dispersion. As internally plasticized resin it requires no mixing or priming to bond molecularly to most construction materials. AU-1 is paintable with no shine through or plasticizer bleed. It has very low VOC content meeting both CARB non-chemically curing sealant VOC (less exempt solvents): <1.5% and SCAQMD (less water and exempt compounds): <50 g/L requirements. AU-1 is extremely UV resistant and maintains high elasticity in all climates. It maintains its adhesive force even after years of exposure by bonding to surfaces through crosslinking on a molecular level. Once cured has exceptional mold and mildew resistance. AU-1 does not lose its elasticity under constant, greatly varying mechanical stress.

Applications

Substrates

Reference TCBSAT-30* for expanded detailed list of applicable AU-1 substrates.

Priming

AU-1 is generally considered a non-priming sealant. It is the user’s responsibility to check the adhesion of the cured sealant on typical test joints at the project site before and during application — consult Technical Services for additional information.

Substrate Preparation

Surfaces to be sealed must be dry and free of all dirt, dust, oil, mildew, loose paint, old caulk or other contaminates. Only apply when sealant, surface and air temperatures are above 40°F and rising. Do not apply on surfaces that exceed 140°F, or when rain is expected.

Installation

AU-1 comes ready to use. U-shaped joints should have the proper size backer rod or bond breaker tape installed to prevent 3-point adhesion. The sealant must reach the deepest point of the joint. Remove excess with a clean rag and water. Tooling the joint flush with a putty knife is recommended. Tooling results in the correct bead shape, a neat joint, and maximum adhesion. 90° joints can be tooled smooth with a moistened rag to a minimum bead size of 3/8″. AU-1 is not intended for use in below-grade joints or in areas that will be subject to frequent water ponding. For new construction, if the roof has not yet been installed, joints should be capped or protected at the top. The preferred method would include a water drainage system at the bottom of the joint. Note, clear will apply white and dry translucent.

Cure Time

@ 75°F (24°C), 50% relative humidity, joint size ½″ × ¼″

Please note that the cure of AU-1 varies with temperature and humidity. Lower temperatures and/or higher humidity will extend curing times. In such cases painting should be delayed until the sealant has time to cure.

Clean-Up / Removal

Immediately after use, clean equipment with soap and water. Remove cured sealant by cutting with a sharp-edged tool. Remove thin films by abrading.

Certification & Testing

*The wet peel adhesion value for Glass prints as “25–2” on the source TDS PDF and looks truncated — double-check against the original before this goes live.

Safety

See the Safety Data Sheet for full safety information, or refer to the product label. To request a Safety Data Sheet, visit towersealants.com or contact Tower Sealants at 866-897-7568. For medical emergencies only, call ChemTrec at 1-800-424-9300. Always confirm you are using the most current version of this Technical Data Sheet and the SDS by calling Customer Service at 1-866-897-7568.