Marine Window Bonding using Sikaflexfr-marine.com/Images/UpFile/201171292438717.pdf · Marine Window Bonding Concepts Page 1 Marine Window Bonding using Sikaflex â A Water Tight

Marine Window Bonding Concepts Page 1

Marine Window Bonding using Sikaflex â

A Water Tight Concept

The bonded window goes beyond the conventional function of a window, providing protection from rain and wind.It not only provides better protection against the weathering elements than the framed window, but it also signifi-cantly improves the design of the vessel. Every car manufacturer bonds the windshield, because of the numer-ous benefits it provides to the overall design of the vehicle. Bonding windows in the automotive industry isreferred to as “direct glazing” and worldwide, Sikaflex

® has been the brand of choice for direct glazing of automo-

biles for many years. The use of Sikaflex®

is now making its way into direct glazing applications of marinevessels all over the world.

What is Window Bonding?

The system is a thermally tempered glass or laminated glass bonded to the structure of the vessel using Sikaflex®

adhesive. Sikaflex®

is a moisture curing polyurethane designed for various bonding and sealing applications.Sikaflex

® adhesives are high-strength elastic adhesives designed to absorb the dynamic stress and thermal

movements that are incurred on the marine window.

The indention where the glass is bonded is referred to as the flange . The flange surface can be fiberglass,aluminum, or steel. The glass is coated with a black ceramic border fused to the glass. The ceramic coating isof a high-density formulation specifically manufactured to protect the urethane adhesive from damaging UVradiation and to provide the ideal bonding surface. You can look at any late model car where you’ll notice asimilar border. Sikaflex

® sealants that exhibit good resistance to UV light and outside weathering are used in

the open joints.

All-round Benefits

The benefits of bonding Marine Windows are the following:

· Increased torsional stiffness.Studies and tests carried out on direct-glazed vessels show that the glass areas effectively functionas stress panels within the overall structure. In this way, they contribute significantly to the structuralrigidity of the vessel, allowing designers to enlarge the window area. Passenger comfort is thereforeincreased from providing a better view of the sea. Useful savings in materials and weight can alsobe achieved, resulting in a greater speed potential of the vessel.

Tempered Glassor Laminated Glass

Ceram icCoating

UV-ResistantSikaflex ® Sealant

Sikaflex ® Adhesive

Flange/Vessel Struct u

Marine Window Bonding Concepts Page 2

· Improved ride comfort.Direct glazing has a positive impact on ride comfort for the passengers. Elastic adhesives reducethe natural or inherent frequencies, and hence the vibrations, in commercial vessel body shells.Similarly, the use of elastic-bonded side windows in marine vessels produces a dramatic reductionin vibration and noise.

· More styling freedom.Direct-glazed vessels open up all kinds of new styling possibilities for the designer. The use ofelastic adhesives makes it possible to integrate dramatically curved areas of glass into the overallbody shape. Curved glass, especially tight radius corner windows do not require custom frames thatcan be difficult and very expensive to manufacture. Direct-glazed vessels create a modern sculptedlook that is also aerodynamically efficient. The elimination of the trim ring and screws result in asleek appearance inside and out.

· Increased Gap TolerancesDirect glazing allows for larger gap tolerances, because Sikaflex® is able to accommodate for smallvariations of the design. The burden of having a precise design connection is significantly reduced.

· Eliminates LeakageSingle step bonding eliminates any chance of leaking that can occur when using the conventionalframed units.

Triangular Bead --> A Leak-Proof System

Sika recommends Sikaflex® be applied using a triangular bead whenever possible. A round bead can trap air,

causing future leaks. A triangular bead minimizes this risk and facilitates in a precise glass fitting.

· Reduced Installation TimeThose who have implemented window bonding into their vessel design have reported a significantreduction of the installation time.

Sika Corporation30800 Stephenson Hwy.

Madison Heights, MI 48071(248) 577-0020

Fax (248) 577-0810

Marine Window Bonding - Design Directives Page 3

Marine Window Bonding using Sikaflex ®

Design Directives

Implementing direct-glazed windows into a vessel structure is a very simple process, with only a few essentialdirectives to abide by. These design directives are in compliance with the Rules for High Speed Light Craft, Pt. 0,Ch. 1, Sec. G300 Glued Windows. Marine classification services, such as DNV, have used the Rules for HighSpeed Light Craft, Pt. 0, Ch. 1, Sec. G300 Glued Windows for their approval process.

1.0 Joint Width/ Gap Distance

2.0 Bond-line Dimensions

3.0 UV Protection - Ceramic Coating

4.0 Surface Preparation – Promoting Good Adhesion

5.0 Corrosion Resistance

6.0 Marine Window Bonding - Project Sheet


1.0 Joint Width/ Gap Distance

The joint width/gap distance between the flange and the window should be large enough to accommodate themechanical movement and thermal movement of the windscreen.

The ideal joint width/ gap distance is:

Ideal Joint Width/ Gap Distance Largest Dimension of Windscreen

3/8 - 5/8” 0 - 5 ft(10 - 15 mm) (0 - 1.5 meter)

5/8 - 3/4” 5 - 10 ft(15 - 20 mm) (1.5 - 3 meter)

2.0 Bond-line Dimensions

It is important to make certain the correct bond-line dimensions are used for each window design. The width andthickness of each adhesive bead needs to account for:

· the weight of the windscreen· mechanical movement caused from operation of the vessel· thermal expansion difference of the glass pane and flange· the head pressure and wind suction load that is incurred on a marine window

The adhesive absorbs the stress from thermal, mechanical, dynamic, and high-impact movements that areincurred on marine vessels, thus relieving the structure from these stresses. The stress is uniformly distributedover the entire bonding surface, which therefore contributes to the structural rigidity of the design.

2.1 Adhesive ThicknessThe adhesive thickness needs to be specified in order to minimize the deformation of the bond-line.

The deformation of the bead is decreased as the thickness is increased. The larger windscreens result in more

Deformation =m ovem entth ickness

Adhesive th icknes

M ovem ent


movement of the bond-line. Therefore, the larger windscreens require a greater adhesive bead thickness. Be-low is the minimum adhesive thickness required for each window dimension.

Nozzles and spacers with specified dimensions must be provided for the installers to ensure the correct bond-

line dimensions are maintained. The height of the triangular bead applied must be twice the size of the adhesivethickness required to ensure full contact of the bonding area.

2.2 Adhesive WidthThe Rules for High Speed Light Craft, Pt. 0, Ch. 1, Sec. G 300 Glued Windows specifies the compressedadhesive width must be the following:

Compressed Adhesive Width < 2 x adhesive thickness

or

Adhesive thickness > Compressed Adhesive Width 2

If the nozzle height is made twice the size of the recommended adhesive thickness, as specified, it should berelatively easy to attain a compressed adhesive width that is in compliance with the Rules for High Speed LightCraft, Pt. 0, Ch. 1, Sec. G 300 Glued Windows.

tAh = 2

h

nozzle width = 3/8"

tA

compressed adhesive width

= adhesive/spacerthickness


3.0 UV Protection - Ceramic Coating

Polyurethane sealants and adhesives are extremely resistant to the effects of weathering and to the cleaningsolutions and methods used in the marine industry. However, when bonding transparent materials, the glass/adhesive interface must be shielded against exposure to UV light, since UV light impinging on the boundary layercan destroy the molecular layer responsible for adhesion within a comparatively short time.Therefore, it is recommended to have a ceramic coating on the perimeter of the glass protecting the bond-line.Sika

® must approve the ceramic coating for sufficient UV blockage. The visible light transmission of the coating

must be less than 0.0001% (Gretag D200 380-630 nm) for use on commercial vessels that require approval froma marine classification such as DNV. Consult your Sika® Representative for a recommended glass supplier.

4.0 Surface Preparation à Promoting Good Adhesion

Preparing the bonding surface area correctly is the most important design directive. Adhesion of Sikaflex®

to the ceramic coated glass and the flange must be verified. Sika® only recommends bonding and sealing with asurface treatment that has been verified through testing by Sika® ’s Technical Service Department. Refer toSika® ‘s Surface Preparation Guidelines for the Sika® Cleaners, Adhesion Promoters, and Primers available andhow they are applied.

5.0 Corrosion Resistance

Sikaflex® products contain no active anti-corrosion additives. Their corrosion-inhibiting effect depends on theexclusion of water and oxygen, both of which must be present for oxidation of the metal to take place. Theprotective effect can be enhanced by the use of Sika® Primers. Long – term protection, particularly againstrusting beneath the paint finish, is normally attainable only by applying a good quality anti-corrosion paint/ primersystem. In such cases it is important to use a paint system that is compatible with Sikaflex®, and whose effective-ness as an anti-corrosion system is specifically warranted by the manufacturer. The window surroundingsshould be given the same full paint treatment as the rest of the vessel body, in order to provide sufficient corro-sion protection.

Sika primer

Paint prim er

Surface coat

Adhesive

Sealant

okdan g er ofcorrosion !ok



Fax (248) 577-0810

Marine Window Bonding - Installation Guide Page 7

Marine Window Bonding using Sikaflex ®

An Installation Guide

1.0 Preparation2.0 Positioning the Window3.0 Installing the Window4.0 Sealing the Window

1.0 Preparation

1.1 Products

Ceramic Coated Glass Flange

Sika®-Aktivator: Sika®-Aktivator Sika®-Aktivator

Sika® Primer:

Sikaflex® Adhesive:

Sikaflex® UV Resistant Sealant:

1.2 Equipment/ Supplies

1.3 Work environment

Make certain the work environment is cordoned off and vacuum cleaned. It must be free from dust, metal shims,wood shavings, silicone, or other foreign materials that would inhibit adhesion.

Cleaning/Application

Scrubs-in-a-Bucket, mineral spirits,MEK, or acetone for cleaning uncuredadhesive.

Lint-free paper towels or cotton cloth.

Non-absorbent, tear resistant, smoothedge masking tape.

Plastic blade for tooling off adhesive.

Dauber or brush for applying primer.

Tools

Fixing aids for assembled glass(clamps, suction cups, woodenblocks) to prevent movement of glasswhile adhesive is curing.

Spacers and support blocks.

Manual, battery or pneumatic gun.

Screwdriver to open cartridges.

Sharp knife to trim nozzles.


2.0 Positioning the Window

2.1 Place spacers on the flange. Spacers should be used to ensure the installer maintains the correct bond-line thickness. A spacer that remains in the adhesive bond must be of the same hardness (Shore A 40-70), as the adhesive. Rubber spacers, coated with pressure sensitive adhesive on one side are commer-cially available. Foam tape with adhesive on one side only may also be used to maintain proper adhe-sive thickness as well as to prevent excessive adhesive flow into the window opening as the glass ispressed against the structure. Never use cyan-acrylic adhesives to fix the spacers. Volatiles from thistype of adhesive can contaminate the adhesion surface and interfere with adhesion build-up.

2.2 Offer the glass to the opening and hold in correct position. Place wooden support blocks (of the correctdimensions) under the edge of the glass to help align the window correctly.

2.3 Place strips of masking tape across flange and windscreen. Then cut through masking tape along theedge of the glass. The masking tape is then used for final alignment once the adhesive has beenapplied.

3.0 Installing the Window

3.1 Make a final check to ensure you have all the required materials and equipment. Once the bondingsurface is prepared, the adhesive should be applied within the next 2-3 hours. This is to avoid having thebonding surface contaminated with dust or debris.


3.2 Use the following surface preparation steps incorporating the Sika recommendation from TechnicalServices.

The specified drying time should be closely adhered to. It is important to wait long enough for thesolvents to evaporate and the binder component to react with the atmospheric moisture. Waiting toolong to apply the adhesive risks having the bonding surface contaminated with dust or debris, thereforethe adhesive should be applied with in 2-3 hours following the surface preparation. The bonding surfacearea should be isolated and not contaminated with oil, grease, perspiration, or any other foreign materials.

3.3 Using the Sika V-cut nozzle, apply a triangular bead of adhesive directly to the glass or flange. Thetriangular bead should be applied 5 mm in from the edge of the glass pane. Make certain the height ofthe triangular bead is twice the size of the specified thickness of the adhesive/spacer. Inspect adhesivebead for voids or gaps which could lead to water penetration pathways.

If the bonding surface is contaminated withoils or other organic substances, initialcleaning using solvents or high-pressurewater cleaning with detergents is necessary.

Lighly abrade with bonding surface area withscotchbrite pad.

Soak a lint-free paper towel with Sika®-Aktivator. Wipe the substrate, turning andchanging the towel often.

Immediately wipe off excess and allow adrying time of 10 minutes.

Apply a thin continuous coat of the recom-mended Sika® Primer using a dauber or brush.

Allow a minimum drying time of 30 minutesbefore applying adhesive.

Surface Preparation Steps: Bonding & Sealing Area

Flange Ceramic Coating

Refer to Sika’s SurfacePreparation Guidelines

Sika®-AktivatorSika®-Aktivator

Sika® Primer _________?Sika® Primer _________?

min. min.


3.4 Install the glass and align in correct position. The glass must be installed within 10 minutes of theadhesive application.

3.5 Press gently around edge of the glass pane to insure good contact with the adhesive. Do not applyextreme force to glass pane as this may cause overcompressure of the adhesive bead.

3.6 Use temporary supports as required to hold the glass pane in place.

3.7 The minimum fixation time of the window is between 30 minutes and 2 hours in conditions of 70°F and50% relative humidity or higher, depending on the adhesive. If the temperature is lower than 40°F, it isrecommended to keep the window fixated overnight.

The minimum fixation time when using Sikaflex___________ in environment conditions of (approximatetemperature/ % of humidity range) _________/______________ is: ______________________ .

3.8 Once the adhesive has cured, the support blocks used to fixate the window must be removed. Twobottom spacers with the same hardness as the adhesive are then permanently placed along the bottomjoint.

Tw o b otto m sp ace rs req u ire dto rem a in in the jo in t fo r e ach w in dow.

(rubb er, c u red ure than e)


4.0 Sealing the Window

If bonding tempered glass, use a recommended UV resistant polyurethane sealant for sealing. The win-dow can be sealed in immediately following the installation. If it is sealed in longer than 2 hours later, makecertain the sealing surface is wiped with Sika®-Aktivator.

If bonding laminated glass, use a neutral type of silicone for sealing.The window should be sealed after waiting 24 hours if the temperature is > 50°F and 48 hours if the temperatureis < 50°F, following the installation.

4.1 Apply a fine line masking tape along the edges of the joints.

4.2 If the joint depth is greater than 5/8”, it is recommended to apply the sealant in two steps or use a backingrod in addition. If the depth is greater than 5/8”, it will take months for the center to cure Extrude thesealant keeping the nozzle completely inserted in the joint in order to avoid air entrapment.

Apply the sealant until it slightly overfills thejoints.

Joint Depth < 5/8”

Extrude the sealant until the joint is half filled.

Allow the sealant to cure overnight.

Wipe the sealing surface with Sika®-Aktivator

In the second application, apply the sealant the sameway allowing it to slightly overfill the joint.

Joint Depth > 5/8”

d j = joint depth Sealant

Adhesive Adhesive


4.3 Tool off the excess sealant immediately using a plastic tool moistened with mineral spirits or a milddetergent water solution.

4.4 Remove masking tape immediately after tooling off, before sealant begins to skin over.

4.5 Wipe away any residue using Scrubs-in-a-Bucket wipes, mineral spirits, acetone, or MEK. *Do notallow alcohol or ammonia to contact curing polyurethane.*

4.6 Make certain the joint is completely filled with adhesive and sealant. Voids allow a place for condensa-tion to occur, where corrosion could take place. Sealant should be tooled off in a slant to avoid a placefor water to collect.



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Properties:

Page 13

Technical Data Sheet

Sikaflex ®-296Marine Window Adhesive

Where to Use:• Marine direct glazing applications,

suitable for use with all types ofglass-based windows.

(Before installation, refer to the SikaWindow Bonding Guide.)

Advantages Offered bySikaflex ®-296:• One-part formulation• Low odor• High initial strength• Excellent working characteristics• Resistant to aging, weathering and

sunlight• Solvent and PVC free• Adheres well to a wide range of

substrates (refer to Sika PrimerChart)

• Can be painted over• Thermally and electrically non-

conductive

Performance Characteristics:Sikaflex®-296 is a polyurethane-based material, which cures onexposure to air (atmospheric mois-ture). Initial strength is derived fromits high viscosity upon application.The excellent non-sag propertiesgrab and hold the glass while thematerial cures with ambientmoisture.

Chemical Resistance:Sikaflex®-296 has very good, longterm resistance to sea water, aque-ous detergents, weak acids and weakbases.

Sikaflex®-296 has temporary resis-tance to hydrocarbons such as gaso-line, diesel fuels and mineral oils.

Sikaflex®-296 has very reduced resis-tance to organic acids, strong acids,strong bases and aromatic aromas.

Description:Sikaflex®-296 is an elastic one-partpolyurethane adhesive that exhibitshigh strength and outstandingworking characteristics.

Sikaflex®-296 has been specificallydesigned for bonding windows tomarine vessel body shells (directglazing). Sikaflex®-296 is manufac-tured in accordance with the ISO-9001 quality assurance system.

10 lb/gal.

45 minutes approximately

1/8" per 24 hours

40 at 77oF

>500%

725 psi

72 pli

> 500 psi

40oF to 110oF

-40oF to 195oF

Black

Packaging:* 20 fl-oz. uni-pacs packaged 20

per carton

Storage:Sikaflex®-296 should not be stored attemperatures in excess of 75oF. Prop-erly stored in cool, dry conditions,the unopened uni-pacs have a shelflife of 9 months.

Coverage:* 20-fl-oz uni-pacs yields 46 lineal

feet of ¼ x ¼-in adhesive bead.

Density

Tack free time*

Rate of cure

Shore A hardness (ASTM D2240)

Elongation at break (ASTM D412)

Tensile strength (ASTM D412)

Tear strength

Lap shear strength (ASTM D1002)

Application temperature**

Service range

Color

*temperature 73oF/50% R.H.**refers to ambient temperature of substrates For optimum application, Sikaflex®-296 should be conditioned to 70o-80oF before use.

Sikaflex ®

Adhesive-SealantSystemsT E C H N I Q U E

Sikaflex ®-296Marine Window Adhesive

Always refer to the Sika Window BondingGuide for complete instructions and guide-lines.

Surface preparation for glass and ce-ramic-coated glass:• If the bonding surface is contaminated

with oils or otherorganic substances, initial cleaning us-ing solvents or high-pressure watercleaning with detergents is necessary.

• Soak a lint-free paper towel with Sika-Aktivator. Wipe the glass and immedi-ately wipe off to provide a very thin layer.Change and turn the towel often to avoidtransferring dirt, oil, etc. from one area toanother.

• Allow a 10 minute drying time. Install thewindow within 2 hours.

• Prepare the bonding surface that theglass is bonding to using the cleaner,primer and procedure recommendedfor that substrate.

Adhesive Application:• Insert uni-pac into gun. Open uni-pac by

cutting off clip as close to the bottom ofclip as possible. Thread endcap ontogun barrel.

• Apply a triangular bead onto the glass.Install glass and align in correct posi-tion. Glass must be installed within 10minutes of adhesive application.

• Use a plastic tool to remove excess

adhesive. Clean up using mineral spir-its, SCRUBS

TM-IN-A-BUCKET, acetone

or MEK.• Allow a 4 hour cure time before subject-

ing the unit to rigorous movement.

Limitations:• Do not apply on frozen surfaces or through

standing water or under water.• Do not apply over silicones or in the

presence of curing silicones.• Alcohol inhibits the cure of Sikaflex® or

any other polyurethane based material.Do not allow Sikaflex® tocontact alcohol and alcohol-containingsolvents during cure.

• Allow a minimum of 1 week full cure priorto total water immersionsituations.

• Maximum chlorine exposure2.5 ppm.

• Do not use as a deck seam sealant.• Do not use to bond organic glass (i.e.

polycarbonate and acrylic).

Important Considerations:• Always protect the bond-line from sun-

light. The perimeter of the glass wherebonded should have a ceramic coatingor an exterior opaque trim. Refer to theWindow Bonding Guide for further infor-mation.

• When applying sealant, avoid air en-trapment.

• Protect from action of water during cureperiod.

CAUTION:

Irritant; Sensitizer: Contains polyisocyanateprepolymer. May cause skin/eye/respira-tory irritation. May cause skin and/or respi-ratory sensitization after prolonged or re-peated contact. Avoid contact. Use ofsafety goggles and chemical resistantgloves is recommended. In case ofexceedance of PELs, use an appropriate,properly fitted NIOSH approved respirator.Remove contaminated clothing.

First Aid:In case of skin contact, wash immediatelyand thoroughly with soap and water. Ifsymptoms persist, consult physician. Foreye contact, flush immediately with plenty ofwater for at least 15 minutes, contact aphysician. For respiratory problems, removeperson to fresh air; if symptoms persist,contact a physician. In case of ingestion,dilute with water and consult physician.Remove contaminated clothing.

Clean Up:Uncured sealant may be removed withsolvent. Cured sealant is only removedmechanically. In case of spills or leaks,wear suitable protective equipment, removephysically and transfer to suitable container.Ventilate area. Avoid contact. Dispose of inaccordance with current, applicable local,state, and federal regulations.

How to use:

Sika warrants its products to be free of manufacturing defects and that they will meet Sika's current published properties when applied in accordancewith Sika's directions and tested in accordance with ASTM and Sika standards. USER DETERMINES SUITABILITY OF PRODUCT FOR USE AND ASSUMESALL RISK. MANUFACTURER’S LIABILITY FOR DAMAGES SHALL BE LIMITED TO THE PURCHASE PRICE OR REPLACEMENT OF PRODUCT. THISREMEDY IS THE EXCLUSIVE REMEDY AND EXCLUDES LABOR AND COST OF LABOR. THERE ARE NO OTHER WARRANTIES BY SIKA OF ANY NATUREWHATSOEVER, EXPRESSED OR IMPLIED, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE INCONNECTION WITH THIS PRODUCT. SIKA CORPORATION SHALL NOT BE LIABLE FOR DAMAGES OF ANY SORT, INCLUDING REMOVAL ORCONSEQUENTIAL DAMAGES, RESULTING FROM ANY CLAIMED BREACH OF ANY WARRANTY, WHETHER EXPRESSED OR IMPLIED, INCLUDINGANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR FROM ANY OTHER CAUSE WHATSOEVER. SIKA SHALLALSO NOT BE RESPONSIBLE FOR USE OF THIS PRODUCT IN A MANNER TO INFRINGE ON ANY PATENT HELD BY OTHERS.

Consult Material Safety Data Sheets and Surface Preparation Guidelines available through SikaFax: 740-375-0063Visit our website at http://www.sikausa.com

Sika® and Sikaflex® are registered trademarks of Sika AG. © Sika Corporation. October, 1999. All Rights Reserved. Rev.10/21/99

Sika Corporation30800 Stephenson HighwayMadison Heights, MI 48071

(248) 577-0020Fax (248) 577-0810

IN CASE OF EMERGENCY CALL CHEMTREC, 1-800-424-9300

CONSULT MATERIAL SAFETY DATA SHEET FOR MORE INFORMATIONKEEP CONTAINER TIGHTLY CLOSED FOR INDUSTRIAL USE ONLY

KEEP OUT OF REACH OF CHILDREN NOT FOR INTERNAL CONSUMPTION

Documents

Marine Window Bonding using Sikaflexfr-marine.com/Images/UpFile/201171292438717.pdf · Marine Window Bonding Concepts Page 1 Marine Window Bonding using Sikaflex â A Water Tight