NOTE: Components must be stored at 12 C (min) for at least 24 hours prior to use.

Transcription

1 PUB. NO LEADERS IN CORROSION PREVENTION THE PROTECTION OF STRUCTURAL STEEL AND PIPEWORK USING THE DENSO STEELCOAT 400 SYSTEM INSTRUCTIONS FOR USE Due to the wide variety of structures, access conditions etc, this document has been designed to provide general guidance only. Please contact your nearest Denso Company or Agent/Distributor for any additional information requirements. APPLICATION TO STRUCTURAL STEELWORK: MAIN COMPONENTS: Denso Penetrating Primer Denso Profiling Mastic Denso Conforming Tape (used for difficult shapes/profiles) Denso Ultraseal Tape Denso Acrylic Topcoat OPTIONAL COMPONENTS: Denso D5 Scrim (Where extra service life or reinforcement is required) Denso Urethane Topcoat (low temperatures) NOTE: Components must be stored at 12 C (min) for at least 24 hours prior to use. MINIMUM EQUIPMENT LIST Clean water / scrubbing brush / heavy chipping hammer / power wire brush and spare pads / paint brush / brush cleaning solvent / empty tins / utility knife / fluted roller / cutting board / tape measure / hard hat / safety goggles / overall / gloves / cleaning cloth / hand cleaner / barrier cream / safety boots / Safety belt if necessary / scaffolding where required. SURFACE PREPARATION: Remove all dirt and salt water deposits by hand fresh water washing or hydrojetting.allow to dry and remove heavy rust or scale with chipping hammers. Power wire brush to achieve St2 standard (ISO ).Where millscale is present, abrasive sweep blasting only is required to remove all millscale. PRIMING THE STEEL SURFACES After surface preparation and removel of all dust, brush apply a uniform coating of Penetrating 6m 2 /litre average over the entire steel surface to be protected.allow solvent to evaporate or until tacky to the touch. SEALING POTENTIAL VOIDS AND AWKWARD SHAPES Internal Corners: Strips of 50mm wide Conforming Tape are first applied into all internal corner sections (see Fig 1&2).After positioning, overwork with the handle of a utility knife or blocking tool to ensure there is no bridging of the tape. Joins should be butt jointed and not overlapped. Remove interleaving backing before application of Ultraseal Tape. Back to Back Angles, Rivets Bolts etc. Inspect all steelwork junctions and apply sufficient Profiling Mastic to fill any voids that may be formed there by the irregularity of the steel members. Profiling Mastic should also be applied around rivets, nuts, bolts etc to mould and form a suitable profile before the subsequent application of Conforming Tape. Pre-cut strips of Conforming Tape from the roll to suit the particular requirements of the awkward shape. Ensure that the interleaving is removed from the compound side (inner side) of the roll before application. Once applied, overwork with finger pressure to ensure full contact to primed steel and/or sealing mastic. Remove protective film from the backing to expose adhesive/glass mesh reinforcement before application of the next strip of Conforming Tape, Ensure overlap to self a minimum of 50% to achieve double thickness. At rivet heads, nuts and bolts etc make two cuts in the Conforming Tape in the form of a cross over the rivet or bolt. Press the tape down thoroughly around the head and apply a small patch of tape to cover the rivet or bolt with at least 25mm overlap all round and press down. For optimum maintenance free service life, D5 Scrim must also be applied in strip form and fully saturated with Denso Acrylic Topcoat or Denso Urethane Topcoat. 1

2 APPLICATION OF ULTRASEAL TAPE INTRODUCTION Denso Ultraseal Tape should be applied to the primed surface within two hours to ensure that an instant bond between tape compound and primer is avoided. This enables the Ultraseal Tape to be repositioned if incorrectly applied. Re-prime if Primer cannot be coated with Ultraseal Tape within two hours. Ultraseal Tape is applied in lengths or strips of one metre maximum.the size of tape to be applied is measured in accordance with the size of steelwork member and cut accordingly (see Fig 3.). GLASS MESH REINFORCEMENT SIDE (WITH INTERLEAVING) Fig 1. COMPOUND SIDE (WITH INTERLEAVING) APPLIED TO SURFACES DENSO CONFORMING TAPE (-CUT OFF STRIPS) Fig 2. PRIMED SURFACE FIRST APPLY A STRIP OF CONFORMING TAPE INTO EACH INTERNAL ANGLE SIZE CUT DEPENDS ON SIZE OF STEELWORK MEMBER 1 METRE STRIP Always choose widths of tape that permit overlaps of at least 25mm and ensure overlaps are applied in a weatherboard fashion. Avoid overlapping the tape on the underside of horizontal surfaces.the following illustrations show the correct way to apply Ultraseal Tape to form overlaps on various structural steel members. Fig 3. Roll of Denso Ultraseal Tape. TAPE INTERLEAVING LAYER IMPORTANT! CUT THROUGH INTERLEAVING LAYER ONLY TAPE INTERLEAVING FIRST TWO CUTS 10mm APART CENTRE OR MIDDLE OF TAPE WIDTH TAPE COMPOUND & ACRYLIC BACKING LAYER Fig 4. Fig 5. THIRD & FOURTH CUTS CENTRED BETWEEN FIRST TWO CUTS AND TAPE EDGES 2

3 REMOVE TAPE INTERLEAVING BETWEEN FIRST TWO CUTS CENTRALISE TAPE AND PRESS DOWN EXPOSED SECTION OF COMPOUND ONTO THE PRIMED SUBSTRATE TO FORM A BOND TAPE INTERLEAVING Fig 6. EXPOSED ADHESIVE COMPOUND Fig 7. SMOOTH TAPE OUTWARDS TOP REMOVE REMAINING TWO SECTIONS OF INTERLEAVING SMOOTHING DOWN FROM THE CENTRE, OUTWARDS, TO EXPEL ALL AIR DENSO CONFORMING TAPE DENSO ULTRASEAL TAPE Fig 8. DENSO PENETRATING PRIMER AN EXAMPLE OF THE CORRECT APPLICATION OF DENSO ULTRASEAL TAPE TO AN RSJ: 25mm Step 1: Step 2: Step 3: Step 4: Step 5: View Fig 9. for correct sequence of tape pieces.always working from the bottom upwards, measure and cut tape piece 1. The tape should run 25mm up the vertical surface (see Fig 9.). Cut the correct width from the roll as shown in Fig 3. Cut interleaving layer as follows in Figs 4&5. The first two cuts should be 5mm each side of the middle or dead centre of the tape width and 10mm apart.the next two cuts should be made between the first cuts and the edge of the tape (see Fig 5). Remove the 10mm wide paper interleave between the first two cuts, leaving an exposed section of adhesive compound down the middle of the tape (see Fig 6). Carefully place and centralise the piece of tape on the section of steel. Once in place, smooth down the back of the tape to form bond with steel section (see Fig 7) With both hands now free the sections of interleaving paper can now be removed from either side of the bonded adhesive compound.the tape is then smoothed down onto the steel section by hand without Fig 9: STEEL RSJ MEMBERS The diagram shows the correct tape configuration for RSJ s with Conforming Tape first applied to internal angles and Ultraseal Tape overlaps forming a weatherboard feature. Step 6: Step 7: Step 8: overstretching by using a downward and outward motion from the centre to expel all air and form an intimate bond (see Fig 8). The tape should be smoothed in to the corner section to ensure full bond to the Conforming Tape. Overwork tape with fluted roller to ensure there are no trapped air pockets. Now measure up and cut tape piece 2.The end of the tape should overlap onto tape piece 1 by 25mm.All overlaps must be thoroughly overworked with a fluted roller to ensure a waterproof seal is achieved. Steps For application of tape pieces 2,3 and 4 follow 9-11: the same procedure as for tape piece 1. 3

4 TOP TOP Fig 10. Fig 11. TOP TOP Fig 12. Fig 13. Fig 10: STEEL CHANNELS The correct tape configuration for steel channels. Fig 11 & 12: STEEL ANGLE MEMBERS The correct tape configuration for steel angle beams. Fig 13: STEEL TEE MEMBERS The correct tape configuration for steel tee beams. OVERCOATING: Once the structure is taped it must be overcoated with a brush or roller application of either Denso Acrylic Topcoat or Denso Urethane Topcoat at a coverage rate of 3m 2 per litre. ADDITIONAL REINFORCEMENT FOR STEELWORK MEMBER APPLICATIONS: For areas where extra mechanical protection or optimum maintenance free service life is required, Denso D5 Scrim is fully saturated with the selected top coat. First apply a thick layer of the top coat to the Ultraseal Tape and then wet in the scrim.the D5 Scrim is applied in pre-cut lengths, similar in size to the Ultraseal Tape application. D5 Scrim absorbs a minimum of 1 /2 litre per m 2 of top coat. 4

5 APPLICATION TO PIPEWORK FLANGES AND FITTINGS: DENSO ULTRASEAL SYSTEM TAPE APPLICATION: Main Components: Denso Penetrating Primer, Denso Ultraseal Tape, Denso Acrylic Topcoat or Denso Urethane Topcoat Optional: Denso D5 Scrim (extra mechanical strength and optimum maintenance free service life). Pipe diameter sizes Recommended tape width 50mm to 75mm - Spiral wrap 50mm 100mm to 150mm - Spiral wrap 100mm 150 mm to 300mm - Spiral wrap 150mm 300mm upwards - Butt Wrap 450mm (Butt wrap method - see below) SPIRAL WRAPPING PIPEWORK UP TO 300mm DIAMETER: Select appropriate tape width from above table e.g. 100mm wide for 100mm diameter pipe. Peel back about 0.5m of interleaving and apply the adhesive side of the tape firmly to the pipe(see Fig 14). Unroll the tape about 0.5m, peel back the interleaving and wrap the tape spirally ensuring correct alignment. Do not overstretch the tape but apply sufficient tension to ensure the tape conforms to the pipe surface. Overlap each turn by a minimum of 25mm (see Fig. 15). Start new roll by overlapping the end of the applied roll by 50mm (see Fig 16.). OVERLAP APPLIED TAPE WITH NEW ROLL BY A MINIMUM OVERLAP OF 50mm Fig 14. Fig 15. Fig 16. Starting the first roll of tape. Diagram showing the correct application procedure for wrapping tape. Starting a new roll of tape. BUTT WRAP METHOD - For all pipes with a diameter greater than 300mm utilise 450mm wide tape widths: Wherever possible the end overlaps of each 450mm wide strips of tape should face away from the general viewing area (see Fig 17.). Utilise minimum 25mm overlaps and apply tape vertically at 90 angle (see Fig 18). Overwork each butt wrap and all overlaps with a fluted roller. WALL TAPE DIRECTION NOTE: MINIMUM OVERLAP OF 25mm PIPE VIEWING AREA OVERLAPS AT 9 O'CLOCK Fig 17. Fig 18. DO NOT OVERSTRETCH TAPE 5

6 OVERCOATING The Ultraseal Tape is overcoated with either Denso Acrylic Topcoat or Denso Urethane Topcoat in the required colour by means of a brush or roller.apply a thick coat at the coverage of 3m 2 per litre (see Fig 19) OR Fig 19. Optional Reinforcement When increased mechanical protection or optimum maintenance free service life is required, Denso D5 Scrim is applied in conjunction with the selected top coat. First apply a thick layer of either Denso Acrylic Topcoat or Denso Urethane Topcoat to the Ultraseal Tape.Wrap in Scrim of appropriate width (select the same size as the tape used in wrapping) in similar fashion to the Ultraseal Tape application. Stagger the Scrim overlaps so that they do not coincide with the inner Ultraseal Tape overlaps.thoroughly saturate the scrim with a suitable brush or roller.absorbtion rate of the topcoat into the D5 Scrim should not be less than 1 /2 litre per m 2 of Denso Acrylic or Denso Urethane Topcoat. APPLICATION OF THE STEELCOAT 400 SYSTEM TO FLANGES AND COUPLINGS: COMPONENTS FOR THE FULL SYSTEM: Denso Penetrating Primer, Denso Profiling Mastic, 150mm wide Denso Conforming Tape, 75mm wide Denso D5 Scrim, Denso Acrylic Topcoat. Alternatives: Denso Urethane Topcoat (low temperatures). IMPORTANT NOTE: AT ALL TIMES PRIOR TO APPLICATION, ALL DENSO PRODUCTS MUST HAVE BEEN STORED AT TEMPERATURES OF NOT LESS THAN 12 C FOR AT LEAST 24 HOURS PRIOR TO USE Surface Preparation: Surfaces must first be thoroughly washed down with fresh water by hand scrubbing or hydrojetting to remove all loose dirt and salt/chloride deposits. Power wire brush to remove all scale, rust and old flake coatings.remove all dust before priming. See Fig Apply Denso Penetrating Primer to all areas to be protected at the average spread rate of 6m 2 per litre. Allow solvent to evaporate or until tacky to the touch. 3. Profile with mastic to cover all bolt heads, nuts etc. See Fig Cut appropriate lengths of 150mm wide Denso Conforming Tape so their length is the distance longitudinally along the pipe, across the profiled coupling, plus mm on each side of the coupling. See Fig 21 and Fig Starting at the underside of the coupling, remove the tape compound interleaving (see Fig 23.) as you proceed and apply the first length of tape longitudinally, along the pipe across the profiled coupling. Apply sufficient finger pressure to the back of the tape to ensure the tape makes full contact with the mastic and the primed pipe surface. Remove plastic backing from the back of the Fig 20. Surface preparation Fig 21. PIECE OF TAPE mm MASTIC Cross section of coupling showing mastic infill and length of tape pieces.

7 tape before applying the next adjacent strip. See Fig 24. Apply the next length of tape overlapping the first. Repeat this process working from the bottom up to the crown of the pipe until half the coupling is covered with tape (tape session 1). Starting from the bottom again, repeat the whole process on the other side of the pipe (tape session 2). See Fig 25 and 26. GLASS MESH REINFORCEMENT SIDE (WITH INTERLEAVING) Fig mm WIDE CONFORMING TAPE REMOVE INTERLEAVING FROM TAPE COMPOUND SIDE BEFORE APPLICATION COMPOUND SIDE (WITH INTERLEAVING) APPLIED TO SURFACES Fig 22. DENSO CONFORMING TAPE (-CUT OFF STRIPS) Fig 25. 'WEATHERBOARD' TYPE APPLICATION OF TAPE STRIPS CROWN Fig 24. REMOVE TOP INTERLEAVING AFTER APPLICATION WORK TOWARDS CROWN KEY TAPE SESSION 1 TAPE SESSION 2 WORK TOWARDS CROWN 6. The tie-in pieces are applied circumferentially around the pipe (see Fig 27.) overlapping onto the edges of the longitudinally applied strips by at least 50mm. During application of the vertical tie in pieces remove the plastic backing from the back of the tape prior to overlapping the tape onto itself (overlaps to self should also not be less than 50mm). 7. The applied Denso Conforming Tape is now reinforced with 75mm wide Denso D5 Scrim. Commencing in the middle or centre of the coupling first applying one complete circumferential turn to lock the D5 Scrim into the adhesive Denso Conforming Tape. Spirally wrap the D5 Scrim working 'TIE IN' PIECES Fig 26. FIRST PIECE OF TAPE down towards the pipe, applying 25mm overlaps (see Fig 28.). On terminating ensure that the D5 Scrim is locked down and pulled into the tacky surface of the Denso Conforming Tape. Repeat application of D5 Scrim to the other half of the coupling.work in the opposite direction from the centre of the coupling, repeating a reverse process back towards the pipe. Finally apply a thick coat of either Denso Acrylic or Denso Urethane Topcoat, ensuring that the D5 Scrim is fully saturated.the D5 Scrim will absorb not less than 1 2 litre of topcoat per square metre of D5 Scrim. SPIRAL APPLICATION OF D5 SCRIM Fig 27. APPLIED VERTICALLY Fig 28. 7

8 REPAIR PROCEDURE FOR ANY FUTURE DAMAGE TO PIPEWORK OR STEELWORK: Fig 29. Fig 30. Damaged pipe coating. Remove loose or damaged area then clean thoroughly. 25mm Fig 31. Fig 32. Prime exposed metal and 25mm each side of the patch. Repair damaged area with a patch of tape overlapping at least 25mm. Overcoat with selected Denso Topcoat. 1. Cut away and remove loose coating from damaged area with a utility knife and smooth or chamfer edges. 2. Clean area thoroughly to remove all flaking material, dust and debris. 3. Prime the exposed metal, extending the Primer onto the sound tape around the damaged area by at least 25mm and allow to dry. 4. Repair the damaged area with a patch of tape cut to a size that overlaps onto the sound tape area by at least 25mm (see Fig 32). 5. Position the tape patch over the prepared area and press down firmly into position.thoroughly work over the patch with a fluted roller to remove all trapped air pockets and ensure optimum contact with the primed substrate. 6. Overcoat the patch and overlap onto the sound coating with either Denso Acrylic or Urethane Topcoat at the coverage of 3m 2 per litre. Denso D5 Scrim 25mm wider than the patch of Ultraseal Tape can also be applied as an option.the Scrim will absorb a minimum of 1 2 litre per square metre of Denso Topcoat. LEADERS IN CORROSION PREVENTION WINN & COALES (DENSO) LTD, DENSO HOUSE, CHAPEL ROAD, LONDON SE27 0TR TEL: FAX: WEBSITE: mail@denso.net Certificate No. FM BS EN ISO A MEMBER OF WINN & COALES INTERNATIONAL 8