Sikaflex Marine Handbook

Instructions forSealing of High-UV-Risk AreasInstructions forPerforming UV-ResistantSealing ApplicationsDescription of ApplicationOn modern ships, yachts and motorboats the joints between differentmaterials must be sealed to protectagainst water ingress, corrosion, etc.In addition, they must also supplyan aesthetic finish to the joint.High-performance sealant joints canbe made with conventionalone-component, polyurethane-basedsystems, which, due to theirexcellent adhesion to varioussubstrates, allow permanentelasticity and resistance againstwater ingress and corrosion.Conventional polyurethane sealants,however, exhibit some sensitivity toUV radiation. After very prolongedperiods of exposure the joint surfacemay exhibit slight degradation. Thisdoes not detract from the sealingproperties, as it is only a surfaceeffect. If a durable surface aspect isrequired, the use of a specificallyformulated, UV-resistantpolyurethane should be considered.Most ships and particularly luxuryyachts and vessels require a largenumber of such joints and hencerequire the use of a high-durabilitysealant. Sikaflex ® -295 UV (Fig. A),in white or black, provides excellentresistance against solar UV radiationand sea water attack, the whitegrade also providing superior nonyellowingcharacteristics.Sikaflex ® -295 UV is thereforeparticularly suited for sealing suchareas as deck fittings, hatches,window rebates, etc.Preparation of SubstrateWood290 DCAbrade contact area on hull withsanding pad (80/100 grit) and removedust with a vacuum cleaner.Apply a thin continuous coat of Sika ®Primer-290 DC, using a clean brush orfelt applicatorDrying time: minimum 60 minutes,maximum 24 hoursAluminium and Stainless Steel205Clean the substrate with Sika ® Cleaner-205, using a clean, lint-free rag orpaper towel. Change frequently!Drying time: minimum 10 minutes,maximum 2 hoursAcrylic and Polyurethane-Based Paint205GRP205206 G+P/215Clean the substrate with Sika ® Cleaner-205, using a clean, lint-free rag orpaper towel. Change frequently!Drying time: minimum 10 minutes,maximum 2 hoursLightly abrade contact area with avery fine sanding pad. Remove dustwith a vacuum cleaner.Clean the substrate with Sika ® Cleaner-205, using a clean, lint-free rag orpaper towel. Change frequently!Drying time: minimum 10 minutes,maximum 2 hoursApply a thin, continuous coat of Sika ®Primer-206 G+P or Sika ® Primer-215,using a clean brush or felt applicator.Drying time: minimum 30 minutes,maximum 24 hoursFor the preparation of othersubstrates, please refer to thePrimer Chart for Sika MarineApplications.Fig. AApplication ofSikaflex®-295 UV Adhesive208Sikaflex ® -295 UV should beapplied to the joint in a bead ofthe required dimensions takingcare to avoid air entrapment.Use a plastic spatula to removeexcess sealant squeezed outaround the edges. Tool to asmooth finish within thetack-free time of the sealantusing Sika ® Tooling Agent N.Traces of uncured Sikaadhesives or sealants may beremoved with Sika ® Remover-208. On no account shouldother cleaning agents or Sika ®Cleaner-205 be used for this.purpose.Important: Please refer to the current SikaTechnical Data Sheets and Safety Data Sheetsobtainable through Sika or their local distributor.Note: Instructions for the use ofspecifically formulated, UV-resistantproducts such as Sikaflex ® -295 UVdo not apply in situations whereUV radiation may directly attackthe bond faces, e.g. transparentsubstrates. Please consult thespecific instructions for theseapplications. Sikaflex ® -295 UV isnot suitable for teak deck caulking.13