Product Description: LIGHTHOUSE KOVER KRACK KNIFE GRADE ELASTOMERIC PATCHING COMPOUND is a high solids, water based, modified acrylic copolymer patching compound which can be used to seal larger cracks (1/16” to 1/4”) in masonry and stucco surfaces. Seals and waterproofs between masonry, wood, glass, wallboard and brick.
Basic Uses Uses: LIGHTHOUSE KOVER KRACK KNIFE GRADE ELASTOMERIC PATCHING COMPOUND may be used to provide a positive patch over nonstructural cracks in masonry, brick, metal, glass, wood, and wallboard. May also be used on non-ferrous and primed ferrous metals.
Surface Preparation: All surfaces must be firm and free of dirt, oil, grease, efflorescence, mildew and loose material. Unsound masonry must be wire brushed or blasted for a firm surface. Dirt, loose contaminates and chalk are best removed by high pressure chemical and water blasting. Any chalk or porous coating not removed by pressure washing must first be sealed with an alkali resistant surface conditioner, such as VIP1200 Surface Conditioner. Prior to applying VIP1200, allow stucco and concrete block mortar to cure 3 days. Poured in-place precast concrete should be allowed to cure 7 days. To remove mildew, scrub with a solution of 3 heaping teaspoonful of Trisodium Phosphate (TSP), 1 quart of Hypochlorite Household bleach and 3 quarts of warm water (wear protective goggles and impervious gloves. Follow manufacturer's directions when working with cleaning solutions). Rinse thoroughly and allow to dry.
Method of Application: SMALL CRACKS: It is not necessary to cut out a crack measuring 1/64” to 1/32”. Simply fill the crack using a wet putty knife or trowel. Make sure that the KOVER KRACK KNIFE GRADE ELASTOMERIC PATCHING COMPOUND is applied generously over the center of the crack at a wet film thickness of 1/16”. Then feather the material to either side of the crack down to zero over a 2” area.
LARGE CRACKS: All voids and joints which exceed 1/32” should be flushed out with water and checked to see that surface is sound and free of grinding dust. If dust is still evident after flushing, seal surface with an alkali resistant surface conditioner to bind the dust to the surface. Once the joint is sound, the use of a bond breaker tape is recommended.
Stage 1: Fill the joint allowing for a small crest to remain. This will compensate for any shrinkage that might occur.
Stage 2: After a minimum of 4 hours cure time, a feather cap of KOVER KRACK KNIFE GRADE ELASTOMERIC PATCHING COMPOUND should be applied at a wet film thickness of 1/16”. This should be placed over the center of the filled joint and “feathered” down to zero over a 2” area.
Clean Up : Clean all equipment immediately after use with warm, soapy water.