All the relevant product data sheets are to be read for additional information like pot life, mixing instructions, surface preparation, ventilation, temperature application limitations, etc.
Surface Coating
The surface coating shall be dura.cote WB water based pigmented elastomeric acrylic topcoat having excellent crack-accommodation available in a range of colours. Use in conjunction with dura.cote WB primer penetrating, hydrophobic, silane-siloxane/acrylic primer.
Uses
For application to prepared backgrounds of atmospherically exposed reinforced and precast concrete and masonry where it is required to minimise ingress of carbon dioxide, chlorides and water, whilst permitting moisture vapour transmission from the structure.
Survey
Areas recently prepared overall with dura.rep FC in accordance with a.b.e.®’s specification will present a surface suitable to directly receive a coating system. See method statement for dura.rep FC.
Areas, where the previous works have not taken account of the need to prepare the overall surface to receive a coating (small patch repairs with little or no fairing e.g.), shall be the subject of an inspection identifying the background character, nature and surface presentation. Information shall be provided to the Contract Administrator detailing the areas for surface coating and the degree of preparation proposed together with techniques to be employed. The technical approval of the Contract Administrator shall be obtained prior to commencement.
Where required by the Contract Administrator trial areas not exposed in the finished work shall first be treated using selected materials. These trial areas shall be noted on the drawings and shall be carried out using the type of materials, mixing procedures, and application techniques that will be used in the contract and shall be approved by the Contract Administrator before the contractor commences the general work. Each colour and finish is to be agreed upon by the Contract Administrator.
Surface Preparation
All surfaces shall be sound, clean and free from dust, plaster, oil, paint, grease, corrosion deposits, laitance, organic growth and any other deleterious substance.
Surfaces shall be cleaned by mechanical means, steam, pressure-washing with clean water, grit blasting, or a combination to satisfy. Any remaining dust or loose material should be removed by blowing with oil-free clean compressed air.
Blowholes, cracks, imperfections and areas of pitting shall be made good with dura.rep FC in accordance with current product information for use. Split water content with dura.latex 50:50 for better adhesion and overall performance.
In hot, humid, coastal situations and in heavy industrial areas ensure that the interval between successive coatings is kept to a minimum. This is to prevent possible contamination of the surface of the preceding coating with air-borne contaminants, resulting in possible inter-coat adhesion failure and reduced coating performance. In the event that delays are unavoidable, wash down the surface thoroughly with clean water before proceeding with the following coating.
Application
Only the specified areas shall be coated; where protection/ masking is required, dependent upon the nature of the coating and its method of application, it shall be provided and installed to the approval of the Contract Administrator. During application, walkways, plants, joint sealants, asphalt and bitumen painted areas and glass shall be masked and shielding shall be provided to prevent animal contact and to prevent airborne coating materials leaving the immediate area of application.
Thoroughly mix all materials in their original containers and progressively intermix containers of the same colours as the job proceeds.
Surface coating materials shall not be applied in rain or when rain is likely within 6 hours of application. The primer shall not be applied when ambient and/or background temperatures are below 5°C or 5°C and falling. The topcoat shall not be applied when the ambient and/or background temperatures are below 5°C or 5°C and falling. Protect all surface coatings materials from frost whilst drying.
Primer
Special care shall be taken to ensure that the recommended application rate of 0.4L/m2 is achieved and two or more applications may be necessary until the dried surface presents a uniform sheen. The primer shall be allowed to dry for not less than 2 hours at 20°C, longer when cooler.
Topcoat
Two coats of dura.cote WB shall be applied. Each coat shall be applied at a minimum wet film thickness of 400 microns. The drying time between coats shall be minimum 16 hours at 20°C and over-coating shall not take place until this period has elapsed and the prior coat is dry. Under poor drying conditions at low temperature it is permissible to apply three coats each of 270 microns wet film thickness.
The finished coating shall be continuous, pin-hole free and have a minimum dry film thickness of 400 microns.
Batch to batch colour variation may occur. Ensure that materials for that application are always drawn from the same batch.
See data sheets for additional information.
Products Required
- dura.cote WB
- dura.cote WB primer
- dura.rep FC
- dura.latex
Equipment Needed
- 150 mm paint brush
- Paint roller – short nap
- Heavy duty Festo mixer with helical mixing head
- Suitable 25 litre mixing bucket
Important Note
This data sheet is issued as a guide to the use of the product(s) concerned. Whilst a.b.e.® Construction Chemicals endeavors to ensure that any advice, recommendation, specification or information is accurate and correct, the company cannot – because a.b.e.® has no direct or continuous control over where and how a.b.e.® products are applied – accept any liability either directly or indirectly arising from the use of a.b.e.® products, whether or not in accordance with any advice, specification, recommendation, or information given by the company.
Further Information
Where other products are to be used in conjunction with this material, the relevant technical data sheets should be consulted to determine total requirements.