Description
Crommelin AquaBlock Waterproof Primer Undercoat is a water-based primer, sealer and stain-blocking undercoat made for damp-prone areas of the home, supplied here in a 1L tin that suits bathroom, laundry and small repaint jobs. It builds a water-resistant, paintable base over bare and previously painted surfaces, so water-based topcoats can go on over an even, sealed surface.
About the formula
AquaBlock is a high-cover, low-odour wall primer with a flat finish. Crommelin positions it as a sealer, primer, undercoat and stain blocker in one product. It grips both porous and non-porous surfaces, seals off stains and gives topcoats a uniform surface to bond to. The manufacturer also describes it as a mould-resistant undercoat, which makes it a sensible choice for bathrooms, kitchens and laundries. It is designed to be overcoated with water-based paints and cleans up with water.
Where to use it
Indoors: walls and ceilings in bathrooms, kitchens, laundries and hallways, especially where steam, condensation or past moisture damage has caused staining or peeling.
Outdoors: eaves and exterior walls and other masonry or timber surfaces that will be topcoated with a water-based paint.
Suitable surfaces include plasterboard, brick, concrete and concrete blocks, cement sheeting, render, masonry, timber, plywood, particleboard and suitably prepared steel.
How to use it
Make sure the surface is clean, dry, sound and free of dust, grease, loose paint and mould before you start. Stir the product well, then apply it with a brush or roller. Check the label for the recommended number of coats and the spread rate for your surface. Apply only when the temperature is at least 5°C. The retailer lists a recoat time of about 120 minutes. Clean brushes, rollers and tools with water straight after use, before the product dries.
Important notes
This product is not tintable and is supplied in white only. Crommelin advises it is not suitable over white set plaster and should not be used as a base before tiling. It is a primer and undercoat, not a decorative finish, so topcoat it with a water-based paint. Surface and weather conditions affect drying and performance, so test a small area first on unusual or heavily stained substrates. Check the label for full application details.
Specifications
| Brand |
Crommelin |
| Product |
AquaBlock Waterproof Primer Undercoat |
| Size |
1L tin |
| Colour |
White (not tintable) |
| Finish |
Flat |
| Base |
Water-based |
| Application |
Brush or roller |
| Coverage |
12 to 14 m² per litre (retailer figure; check the label) |
| Recoat time |
About 120 minutes |
| Minimum application temperature |
5°C |
| Clean up |
Water |
| Topcoat |
Water-based paints |
| Use |
Interior and exterior |
Safety
Even so, avoid contact with skin and eyes, wear suitable protective clothing and gloves, and use it in a well-ventilated area. Keep the lid on the tin when not in use, store it in a cool, dry place and protect it from freezing. Keep it out of reach of children. Do not tip leftover product or wash water into drains or waterways. Refer to the Safety Data Sheet (SDS) for full details.
