550 Water Based Matte Polyurethane Concrete Sealer is a flat finish, two-component urethane resin. The Part A component must be thoroughly mixed into the Part B component for the material to properly cure and provide a durable, long-lasting finish. This product can be applied indoors or out to smooth concrete surfaces. Rough or broom-finished concrete are not good candidates for this sealer. Careful review of the product instructions prior to applying is a must. Low gloss, no wax sealer alternative for indoor floors. Available in 1 gallon kits for large countertop or flooring applications and mini kits suitable for most countertop or concrete decor projects. Notched squeegees are not intended for use with this product.
Coverage: When properly applied to a smooth concrete surface, the 1 gallon kit will cover up to 300 sq. ft. Coverage will vary with surface conditions and concrete porosity. The mini kits will cover 65-75 sq. ft. per kit. If top-coating a previously sealed surface, the kit will cover up to 500 sq. ft. Use only water-based acrylic or epoxy sealers to prime the floor or countertop surface.
Surface Preparation: All surfaces should be clean, dry and free of any debris prior to application. Sand down or fill with slurry all “pinhole” air pockets or voids in the countertop surface prior to application. Sand and repeat until all pinholes and voids are filled. The surface should be polished to no more than 200-grit prior to sealing. See our video, How to Make and Apply a Countertop Slurry Parts 1 and 2, for more information.
Priming the Floor and Countertop Surface: For best results, first apply a single thin coat of DCI Water Based Sealer for smooth surfaces or two thin coats for more porous surfaces. Allow the primer to cure 12 hours between primer coats and a minimum of 24 hours before proceeding. Priming reduces the risk of air bubbles, promotes good sealer adherence and slightly extends the DCI 550 Polyurethane coverage rate.
Mixing Instructions: As a two-part system, Part A must be thoroughly mixed into Part B in order for the material to properly set up for application. Pour Part A into Part B and begin to mix with a wooden stir stick. Mix completely; fold the material over onto itself and carefully scrape the sides of the can to assure nothing is left unmixed. The contents should thicken and become whiter as you stir. Stir for 2-4 minutes until totally combined. If mixing a 1 gallon kit, use a low speed electric drill (maximum 650 RPM to avoid bubbling) and a jiffy mixer attachment to combine. DO NOT mix the product at a high-speed.Once mixed, the pot life for the sealer is approximately 1 hour.
Application Instructions: When applying in optimal temperature and humidity conditions of 75 F and 50% humidity, 550 Polyurethane pot life is approximately 1 hour before the material begins to harden. Do not apply to surfaces below 65F or above 90F or if humidity levels are above 80%. Lower temperatures will maximize pot life and higher temperatures will reduce it. The sealer itself must be above 60F before installing.
Floor Application: 550 Matte Polyurethane Sealer can be applied using a de-fuzzed 3/8″ nap roller from a paint tray. Working time for this material once rolling begins is 5-8 minutes. Having one person mixing 1 gallon kits and one person applying is essential to success for larger projects. Applying beyond the recommended working time can result in streaking, a milky appearance and/or an uneven finish.
550 Matte Polyurethane can also be sprayed from an HPLV sprayer using compressed air. If spraying indoors, cover the floor and other surfaces from overspray before applying. Clean the HVLP sprayer according to instructions before beginning the project. Set the air compressor to approximately 40 PSI. Mix the polyurethane as per the mixing instructions and pour into sprayer container. Spray an even, consistent coat onto the surface. Avoid pooling during application as the milky color will not clear if sealer is applied too heavily. Thirty minutes after the first coat, spray a second coat and allow to dry.
For complete application instructions, read our How-to Apply Water Based Polyurethane Guide.
Countertop Application: 550 Matte Polyurethane Sealer can be applied either with a de-fuzzed 3/8″ nap roller or with HVLP Gravity Feed Spray Gun with compressed air for finer finish. For complete application instructions, read our How to Apply Polyurethane Countertop Sealer Guide.
Cure Time: Surfaces sealed with DCI 550 Matte Polyurethane should cure for 12 hours at approximately 75F before use. Allow for additional drying time in the event of high humidity or low temperatures.
550 Matte Polyurethane can be cleaned from tools and sprayers prior to cure with hot soapy water. Once fully cured, the product can be removed industrial paint strippers, such as the Soy Gel Paint and Sealer Stripper, or by wet sanding with a 120-220 grit pad or use dry non-loading sandpaper. Leftover product, brushes, paint trays, or roller covers should be responsibly discarded after use.
Key 550 Water Based Matte Polyurethane Concrete Sealer Features:
• Water-based, Low Odor, Highly Durable Flat Polyurethane Coating
• Apply using either a roller or an HVLP sprayer
• No wax required sealer alternative for indoor floors
• Can be applied with a water-based acrylic prime coat indoors for increased coverage area
• VOC compliant everywhere but California
• Available in both mini kit and 1 gallon kit sizes