Sealer for Black Concrete

by Grant Thomas
(Sydney, Australia)

I have black concrete which has had oxide put into the pour to make it pitch black. However after it dried the colour intensity is nowhere near as black as it appeared it would be when it was wet. Add water to the surface and it's midnight black. Allow it to dry and the colour recedes. Can you tell me if there's a process whereby I can get the intensity to remain after the surface dries. If I was to add a black stain which contains 60% Diacetone Alcohol before I finish the surface with a Lithofin Stainstop oil repellant plus colour enhancing impregnator (contains aphtha hydrodesulphurized heavy reactive polymer / n-butyl acetate and auxillery agents) will I alter the cementious formula of my concrete. The concrete was poured 2 years ago.

A. You don't need to stain the concrete, all you need to do is seal the concrete with a film forming (topical) acrylic and solvent based concrete sealer. This will darken the concrete and give it the "wet look" you are looking for. Many companies sell this kind of sealer, some label it as a "wet look" sealer or "decorative concrete" sealer. There are water-based versions but the solvent based works best.

I buy my concrete sealers from elite crete systems. There is a distributor in Australia called elite crete australia. Check with them for the correct type of sealer to purchase.