Surface Preparation
New Concrete
Approximately ten days after laying, new concrete can generally be primed with Watco Surface DPM to seal in residual construction moisture before overcoating with Watco Epoxy Matt Coat. Please refer to the
Watco Surface DPM datasheet for details.
Concrete at least 4 weeks old
Concrete to be treated must be completely dry and free of surface laitance (a weak dusty layer on concrete), contaminants and any previous poorly bonded coatings. All traces of grease or oil should be removed with
Watco Bio D (or a similar degreasant) and the area thoroughly washed off and allowed to dry. Very smooth concrete or concrete with surface laitance should be etched with
Watco Cemtetch to ensure adequate adhesion. The concrete should be thoroughly washed down and allowed to dry after treatment with Watco Cemtetch.
Watco Powerfloat Primer is available for highly polished or power floated surfaces.
Painted surfaces
Previously painted surfaces should be thoroughly abraded by sanding or wire brushing (eg with a scarifying machine) to improve adhesion and to remove any weak or loose material. A trial area should be completed to test adhesion to previous coatings.
Mixing
Remove the two inner tins from the tall outer tin. Stir the contents of each tin thoroughly and pour all of the contents into the outer tin (scrape around the inside of the tins to remove any residue). Mix the components together thoroughly using a spatula or similar wide bladed tool (a piece of wooden batten is ideal). Continue mixing until an even colour and consistency are obtained. Do not mix more than one pack at a time. If a paint stirrer fitted to an electric drill is used, also use the spatula to blend in any unmixed material from the sides and bottom of the tin.
Application
Best results are obtained in warm (minimum 15°C), dry conditions with a good through draught. In very high temperatures (30°C and above) it is recommended that bare concrete is lightly dampened first with water. In exceptional temperature conditions advice should be obtained from Watco’s Technical Department.
Apply by simulated sheepskin roller, working well into the surface of the concrete. Do not exceed the maximum coverage of 30m² per 5 litre pack, per coat. Some colours may darken slightly as curing commences and it should not be over rollered. The second coat can be applied as soon as the first coat is dry (generally next day) and should be applied within 5 days. If more than 5 days elapse, the first coat should be lightly abraded before the second coat is applied.
