The simplest way to check if the surface is open enough is the water test:
- Pour a small amount of water (a few inches wide) on the concrete in several spots.
- If it soaks in immediately, the surface is porous and ready for coating.
- If it beads up or sits on top, the surface is too tight (common with hard-troweled concrete), and you'll need to diamond grind to open the pores.
Acid etching can work in some cases, but for best results we usually recommend light diamond grinding instead.
Etching only reacts with the surface paste, so it doesn't always open up dense or hard-troweled concrete evenly. A grinder with a diamond wheel gives you a more consistent profile for the
DeltaDye and
HD6600-MMA to soak in and bond properly.
If you prefer to etch, try our
HD357 Concrete Etch
The water test after etching will tell you if it worked and if the water absorbs right away, you're good to go.
