Watco Etch & Clean is a highly effective hydrochloric acid based etchant which removes surface laitance (a weak, cementitious dusty layer) from new, bare concrete prior to painting. Failure to remove laitance prevents paint bonding to the concrete and can lead to it peeling off the when the floor is put into use.
This unique dual action formula saves time since it both etches (provides a key) and cleans bare concrete ready for painting in one simple application. Etch & Clean reduces the alkalinity in new concrete.
High alkaline levels in new concrete can soften newly applied paint, especially single pack alkyd based paints such as Watco Concrete Floor Paint. Etch & Clean is easy to use. Unlike other floor etchants it has a thick, gel like consistency which allows greater control when applying the product to the floor. This results in a more evenly etched finish and so promotes more effective paint adhesion.
To help with application, the product has an added pH indicator, which changes from pink to clear once the surface has been prepared effectively.
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Features & Benefits
- Prepares any bare concrete prior to painting
- Use on old and new concrete, inside or outside
- Etches bare concrete to promote adhesion of paint finishes
- Removes dirt and light oil deposits
- Removes cement deposits from new concrete to ensure good paint adhesion
- Reduces alkalinity of new concrete – essential prior to application of single pack paints such as Watco Concrete Floor Paint
- Easy to use – unique gel formulation allows even etching
- Colour change system – when the pink liquid turns clear you know the job is done
Heavily contaminated Concrete – Heavy grease deposits should be removed using Watco Concroff, flushed with clean water and left to dry prior to etching.
Particularly porous surfaces – should be dampened slightly with water prior to applying Etch & Clean.
As a guide, new concrete should be left for four weeks to dry in the summer and six in the winter if you are intending to apply a waterbased coating after etching, and eight weeks for a polypaspartic or high build coating (contact us for advice if you are unsure).
Bare Concrete surfaces – Apply Etch & Clean to a maximum area of 20m2 (see section headed Coverage) per 5 litres in conjunction with harsh scrubbing by stiff broom or machine and leave for 15 minutes until all frothing stops and the formulation has changed from pink to white/clear. Once the colour change has occurred the surface alkalinity has been fully neutralised. Flush the area with generous amounts of water to remove all traces of Etch & Clean and allow the area to dry thoroughly before painting. Brush and vacuum the surface to remove loosened particles of laitance.
How to tell if the surface laitance has been completely removed - after treatment with Watco Etch & Clean the surface should be inspected to ensure that all deposits of laitance have been removed. Test the surface by scraping it with the edge of coin. If a fine powdery film can still be easily removed from the surface etching with Watco Etch & Clean will need to be repeated.
Do not apply to bare metal which is prone to rusting such as mild steel. Protect machinery or other objects to prevent corrosive attack from spillage or fumes.
Do not apply on painted or sealed surfaces; this product is suitable only for bare, porous concrete.
Etch & Clean is unsuitable for sand and cement screed floors and self-levelling compounds.
Where decorative surfaces are being treated it is advisable to test a small area first to ensure that there are no harmful effects to the material to be cleaned or to the surrounding surfaces.