Karna-Flex WB (505 Seam Sealer)
Karna-Flex WB is an acrylic elastomeric, water-borne mastic formulated for use on built-up asphalt roofing, modified bitumen membranes and properly prepared metal, concrete, spray polyurethane foam and plywood roof substrates. Its ease of application, superior adhesion, elasticity and durability make Karna-Flex WB an ideal repair sealant.
Karna-Flex WB’s elastomeric properties make it an excellent sealant for making repairs to built-up asphalt roofs, modified bitumen membrane roofs, prepared metal, concrete, spray polyurethane foam and plywood roof system details. Ideal for sealing flashings, curbs and waterproofing metal roof seams, gutters, fasteners, pinholes in metal and skylights. Excellent for sealing flashings on asphalt BUR roofs and modified bitumen membrane roofs. Ideal for sealing around penetrations and roof top equipment. Use in place of flashing cement for repairs to all types of asphalt roofs prior to applying white coatings.
1. Complies with all V.O.C. requirements and regulations.
2. Water-borne, non-flammable, odorless and non toxic.
3. One component - no need to intermix with other materials.
4. Easy application by brush, roller or spray.
5. Easy clean-up with water prior to curing.
6. Superior film - forms a durable, weather resistant elastomeric membrane.
7. Has superior adhesive and cohesive strength.
8. Fungistatic - formulated for most advanced, state-of-the-art resistance to mold or mildew growth.
9. Low temperature flexibility - specially selected internally plasticized polymers impart superior low temperature proper - ties to the coating.
All surfaces to be sealed must be dry, clean and free from rust, loose coating and caulk, oil, grease and other foreign matter. Remove silicone or other sealants before using.
Karna-Flex WB should be applied by stiff brush or bulk loading caulking gun, depending on the application. Apply sealer when temperatures are above 50ºF and rain is not forecasted within 24 hours. For sealing flashings and lap seams use fabric reinforcement between layers of Karna-Flex WB. Apply sealer in a 1/16” to 1/8” width then immediately embed Karnak 5540 Resat-Mat polyester fabric into the wet coating. Smooth out fabric then apply another layer of sealer. Some shrinkage may occur and require an additional application of Karna-Flex WB
For metal roofing follow these application guidelines:
• Horizontal Seams and Cracks 1/16” wide or larger.
Screws/Fasteners, Vertical Seams and Cracks less than 1/16”
• Using Karnak 550 Patch-N-Go Fleece Tape, adhere tape to crack as directed per product
application guidelines. Apply Karna-Flex WB at an average thickness of 1/16” to completely
cover the polyester face of the tape and feather out.
• Using Karnak Resat-Mat, apply a 1/16” thick application of Karna-Flex WB then
immediately embed one ply of Resat-Mat polyester fabric into the wet coating. Smooth out
fabric then apply another layer of Karna-Flex WB.
• Over screws and fasteners apply a dollop of Karna-Flex WB to completely enclose the
screw/fastener with either a 2” wide brush or bulk loading caulking gun.
• Over vertical seams and cracks less than 1/16” wide, back brush a minimum 2” wide
application of Karna-Flex WB at an appropriate thickness of 1/16” to 1/8”.
Note: Allow to cure 24 hours before coating over, if desired. Not intended for use in ponding areas.
1. Weight per Gallon: 12.5 lbs
2. Solids by Weight: 75%
3. Color: Off-white
4. Modules @ 100%: 15-20 psi
5. Tensile Strength: 30-40 psi
6. Elongation: 400-500%
7. Low Temp Flex
8. ASTM-C-734: No cracking/pass
9. Recovery: 75% min.
Do not apply when rain is imminent. Protect from freezing. Coating must be dried before exposure to water. Store in a heated room and keep container covered when not in use. Do not thin. Avoid prolonged contact with skin. Dispose of in an environmentally safe manner.
COLD-PROCESS SYSTEMS AND COATINGS, EITHER EMULSION OR SOLVENT BASED, SHOULD ONLY BE INSTALLED ON DECKS WITH POSITIVE DRAINAGE.
PER NRCA, (NATIONAL ROOFING CONTRACTORS ASSOCIATION) "THE CRITERIA FOR JUDGING PROPER SLOPE FOR DRAINAGE IS THAT THERE BE NO EVIDENCE OF STANDING WATER ON THE DECK 48 HOURS AFTER IT STOPS RAINING."
- Seam Sealer: 2 gallon POT