Gluing windows with SABA Glasstack 760

Transcription

1 Info sheet 208 Gluing windows with SABA Glasstack 760 Version EN, replaces all prior versions

2 Page 2 of 9 Info sheet 208 Gluing windows with SABA Glasstack 760, version EN 1. Introduction Various types of glass and plastic windows are used in yacht construction. In order to absorb the expansion of these materials, the windows are glued with SABA Glasstack 760, a high-quality, extremely elastic product, specially developed for gluing windows. SABA Glasstack 760 is thixotropic, allowing broader joints to be made, and has a high initial adhesive strength. A black primer protects the joint from UV light. SABA Glasstack 760 features: - High degree of resistance against the effects of moisture, (salt) water, acids, oily substances and UV radiation - No blister formation - Very durable connection - Good resistance against ageing - Quick and easy processing (ready to use) - Does not contain any solvents, isocyanates, silicon or PVC - Does not corrode metals This info sheet describes gluing of ship windows subject to average mechanical stress. This involves: - Glass windows with maximum dimensions of 0.5 m x 0.5 m - Plastic PMMA and polycarbonate windows with maximum dimensions of 0.5 m x 0.5 m - Windshields. Ask SABA for advice on gluing windows larger than 0.5 m x 0.5 m. We recommend subjecting the material to adhesion tests in advance. Always use the primer recommended by SABA (see the primer list at the end of this info sheet). 2. Glued window structure 2.1 Joint dimensions Windows in yachts are subject to heavy stress due to the action of the boat, the various expansion coefficients of the materials and the climate conditions, such as wind and changes in temperature. The dimensions of the joints must be such that these stresses can be absorbed. The following guidelines apply to joint dimensions in yacht construction: - Width of the joint round the edge of the window (rebate) must be 10 mm minimum. - The minimum thickness of the glue layer is 4 mm. Use spacers to achieve this thickness (see section 3). - The thickness of the glue layer must be half the width of the joint (Thickness = 0.5 x Width).

3 Page 3 of 9 Info sheet 208 Gluing windows with SABA Glasstack 760, version EN Minimum dimensions of the glue layer Observations: - The size of screw holes for mechanical attachment of plastic windows must be sufficient to absorb action of the windows. - Width and thickness of joints must correspond to the dimensions of the window to absorb expansion of the various materials. 2.2 Protection of the glue layer from UV light UV light may affect the adhesion of the glue to the glass. Therefore, it is important to provide the glue extra protection against the effect of UV light. There are three methods to provide protection: - Method 1: a window equipped with a ceramic edge on the inside. - Method 2: priming the window with SABA Primer 760. This primer is impermeable to light. - Method 3: install a cover strip along the outside. Method 3, a cover strip along the outside, provides the best protection. The rule for this method is that the cover strip overlap must be at least 2 x the thickness of the glass. The three methods are shown in the drawings below.

4 Page 4 of 9 Info sheet 208 Gluing windows with SABA Glasstack 760, version EN Method 1: ceramic edge on the window Method 2: a layer of SABA Primer 760 on the window Method 3: cover strip (moulding) on the outside

5 Page 5 of 9 Info sheet 208 Gluing windows with SABA Glasstack 760, version EN 3. Steps in gluing General observations: - Wear (latex) gloves to prevent oil from the skin getting on the substrate. Use lint-free paper towels to remove the oil. - Protect your work from bright sunlight and rain during application. - Work in a draft and dust-free area. Application must be done in wind-free and frost-free conditions. - The window is usually sealed all round at the same time it is glued. However, it is also possible to seal the window later. Step 1: Cleaning and removing grease from the substrate Make sure the substrate and the window are dry, clean and dust-free and that any silicon residues have been removed thoroughly. Use SABA Cleaner 48 to remove grease. Allow the solvent to evaporate thoroughly (15 minutes minimum). Step 2: Taping You obtain a straight joint and prevent unnecessary cleaning by taping with masking tape. Remove the masking tape as soon as the sealant has been applied. Step 3: Priming the substrate or rebate Apply one layer of primer on the substrate or rebate, using a brush or a primer ball. Allow this to dry well. The primer table in the back of this info sheet specifies what SABA primer is suitable for what type of substrate. Observations: - All metal surfaces (stainless steel, thermally galvanised steel, anodised aluminium) must first be thoroughly degreased with SABA Cleaner 48 and primed with SABA Primer Anodised aluminium is the only exception and can be glued or sealed without primer (but must of course be degreased). - Thoroughly remove the mill scale, any rust and other contaminants from steel. - Then prime with SABA Primer Pretreatment of aluminium is very important: new aluminium has a greasy surface and must be properly degreased. Remove the oxidation layer of old aluminium by sanding lightly. Then prime with SABA Primer New polyester must be at least 4 weeks old before it can be glued. Wash the polyester thoroughly with water and liquid soap to remove all water soluble dirt. Next remove all waxy components, conforming to the recommendations from the polyester supplier. Degrease new polyester several times with SABA Cleaner 21. Allow the substrate to evaporate well (styrene free). Then prime with SABA Primer 9102.

6 Page 6 of 9 Info sheet 208 Gluing windows with SABA Glasstack 760, version EN Step 4: Priming the window The priming process for glass windows is different from that for plastic ones. Glass windows The following applies to glass windows: - Glass windows with a (black) ceramic edge do not have to be primed. Degreasing with SABA Cleaner 48 suffices in this situation. - Glass windows which will have a cover strip on the outside do not have to be primed. Degreasing with SABA Cleaner 48 suffices in this situation. - In all other cases, the glass window must be pretreated by first degreasing it with SABA Cleaner 48 and then priming with SABA Primer 760. The primer protects the glue layer from UV light. Plastic windows The following applies to plastic windows: - There are many different types of plastic windows available on the market. Whether SABA Primer 760 should be used depends on the specific type of plastic. SABA recommends subjecting the plastic window to be glued to adhesion tests in advance. In case of doubt, ask SABA for advice. - Plastic windows that do not have a light-impermeable edge or for which no cover profile is being used should always be pretreated with SABA Primer 760 in order to protect the glue layer from UV light. - Degrease plastic windows with SABA Cleaner 48. Attention: be careful when cleaning the windows with solvents due to the risk of damaging the material. SABA recommends first always testing the tolerance of the material to the solvent on a left-over piece! Applying Primer Thoroughly remove any solvents left from production from the windows using SABA Cleaner 48, or water in case the solvent is water soluble. Use lint-free paper towels only when cleaning. After degreasing, allow the solvent to evaporate thoroughly before applying the primer. Apply one layer of primer to the window, using a brush or a primer ball. Allow this to dry well. Attention: SABA Primer 760 is sensitive to moisture in the air. Therefore, close the packaging immediately after use! After the package has been opened, SABA Primer 760 has a limited shelf life. Step 5: Placing spacers Place 4 mm spacers between the glass sheet and rebate, in order to prevent the sealant from being pushed out and to guarantee a minimum glue layer of 4 mm. Also place spacers under the window to prevent the window from sliding down.

7 Page 7 of 9 Info sheet 208 Gluing windows with SABA Glasstack 760, version EN Spacers between glass sheet and rebate Step 6: Applying SABA Glasstack 760 Apply SABA Glasstack 760 within the "open time" of the primers used. Apply SABA Glasstack 760 using a suitable manual or compressed air sprayer. Prevent air bubbles from getting trapped by applying SABA Glasstack 760 evenly. Use the v-nozzle included with the delivery to obtain a triangular SABA Glasstack 760 glue groove. When installing the window, the triangular joint is compressed into a square joint. Make sure that the temperatures of the sealant, the substrate, the window and the ambient temperature are not significantly different from each other. The air temperature must be between +5 C and +35 C. See also info sheet 003 Measuring moisture and dew point. Step 7: Installing, securing and finishing the window Install the window within 10 minutes (= open time) after the glue has been applied. Set the window in the right place the first time. Attention: the open time is shorter at a higher temperature and high humidity. Secure the window mechanically or with tape until the sealant has hardened. The speed of hardening depends on temperature and humidity. Smooth out the excess sealant immediately after installing the window, and wipe it with a spatula dipped in soapy water (neutral and acid-free soap, approx. 5% solution in water).

8 Page 8 of 9 Info sheet 208 Gluing windows with SABA Glasstack 760, version EN 4. Repairs and maintenance Remove any bad or damaged joints completely. Next start gluing or sealing again from the base up. Attention: be careful when cleaning the windows with solvents due to the risk of damaging the material. SABA recommends first always testing the tolerance of the material to the solvent on a left-over piece! 5. Primer tables 5.1 Primer table for SABA Glasstack 760 The table below shows what primers should be used when priming the substrate: Substrate Primer to be used Aluminium SABA Primer 9102 Anodised aluminium SABA Cleaner 48 Stainless steel SABA Primer 9102 Polyester SABA Primer 9102 Epoxy resin SABA Primer 9102 Steel SABA Primer 9102 Thermally galvanised steel SABA Primer 9102 Ask SABA for advice if the substrate you want to glue is not in the table above. 5.2 Open times for SABA Primers and Cleaners Primer or Cleaner Open time minimum maximum SABA Cleaner minutes not applicable SABA Cleaner minutes not applicable SABA Primer minutes 24 hours SABA Primer minutes 30 minutes 6. References - SABA Glasstack 760 safety information sheet - SABA Glasstack 760 product sheet - SABA Primer 760 safety information sheet - SABA Primer 760 product sheet - SABA Primer 9102 safety information sheet - SABA Primer 9102 product sheet

9 Page 9 of 9 Info sheet 208 Gluing windows with SABA Glasstack 760, version EN - SABA Cleaner 21 safety information sheet - SABA Cleaner 21 product sheet - SABA Cleaner 48 safety information sheet - SABA Cleaner 48 product sheet - Info sheet 201 SABA products for boat construction - Info sheet 003 Measuring moisture and dew point