Marine Application Guide
5.8 Sealing Areas Exposed to UV Radiation
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.
Marine Application Guide
Performing UV-Resistant Sealing
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
for teak and use Sika® Primer-215 for sealant squeezed out around the edges.
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
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
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
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!
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!
Flash-off: minimum 10 minutes, maximum
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.