VIEWS: 4 PAGES: 2 POSTED ON: 11/2/2011
Marine Application Guide 5.8 Sealing Areas Exposed to UV Radiation Application Description On modern ships, yachts and motor boats the Conventional polyurethane sealants, however, Sikaflex®-295 UV, available in either white or joints between different materials must be exhibit some sensitivity to UV radiation. After black, provides excellent resistance against sealed for water-proofing, corrosion, etc. But prolonged periods of exposure the joint may solar UV radiation and seawater attack, the they must also supply an aesthetic finish to the show fine cracks and degradation at the surface. white grade also has superior non-yellowing joint. This does not affect the sealing properties, as it characteristics. High-performance sealant joints can be is only a surface blemish. If a durable surface Sikaflex®-295 UV is therefore particularly suited made with conventional one-component, aspect is required, a specifically formulated, UV- for sealing such areas as deck fittings, hatches polyurethane-based systems, which, due to resistant polyurethane should be used. and window rebates. their excellent adhesion to various substrates, Most vessels and in particular, luxury yachts, allow permanent elasticity and resistance require a large number of such joints and hence against water ingress and corrosion. require the use of a high-durability sealant. 74_Sika Transportation Marine Application Guide Performing UV-Resistant Sealing Applications Substrate Preparation Wood GRP Applying Sikaflex®-295 UV Adhesive Abrade the contact area on the hull with a Lightly abrade the contact area with a very Mask the surrounding area before priming sanding pad (80/100 grit) fine sanding pad and sealing Remove the dust with a vacuum cleaner Remove the dust with a vacuum cleaner Sikaflex®-295 UV should be applied to the joint in a bead of the required dimensions 295 taking care to avoid air entrapment Apply a thin continuous coat of Sika® Pretreat the substrate with Sika® Aktivator, UV Primer using a clean brush or a felt using a clean, lint-free rag or a paper towel. Change the rag frequently! Use a plastic spatula to remove excess 290 DC applicator. Use Sika Primer-290 DC LOT ® Aktivator for teak and use Sika® Primer-215 for sealant squeezed out around the edges. LOT or 215 other wood N Tool to a smooth finish within the tack-free Flash-off: 10 minutes (min) to 2 hours time of the sealant using Sika® Tooling (max) Agent N Drying times: Sika® Primer-290 DC LOT - 30 minutes (min) to 3 months (max) Apply a thin, continuous coat of Sika® Uncured Sika adhesives or sealants may Sika® Primer-215 - 30 minutes (min) to 24 Primer-206 G+P or Sika® Primer-215, be removed with Sika® Remover-208 and hours (max) 206 using a clean brush or a felt applicator 208 remove the masking tape G+P 215 Do not use Sika® Aktivator or any other Aluminium and Stainless Steel cleaning agent or solvent for cleaning Drying time: 30 minutes (min) to 24 hours purposes (max) Pretreat the substrate with Sika Aktivator, ® For bonding transparent substrate please using a clean, lint-free rag or a paper refer to Section 6.7 and 6.8 towel. Change the rag frequently! Aktivator Acrylic and Polyurethane-Based Paint Please consult Sika Technical Service Flash-off: 10 minutes (min) to 2 hours Department if joints are prone to high (max) Pretreat the substrate with Sika® Aktivator, dynamic stresses using a clean, lint-free rag or a paper towel. Change rag frequently! Aktivator Flash-off: minimum 10 minutes, maximum 2 hours For the preparation of other substrates, please refer to the Pretreatment Chart for Sika Marine Applications on page 146-147 or contact your local Sika organisation. Sika Transportation_75
"Sealing Areas Exposed to UV Radiation"