Usually, oil or water-based sealers for granite are required to make the stone more durable and stain-resistant.
However, black granite is not easy to apply an impregnating granite sealer, especially for a honed finish.
If the sealer can’t work, the surface may gets white rings or hazy streaks which cannot be wrapped off.
You will have to try to re-polish the surface to remove the defects. Even tricky, if part of granite
color tone gets change, problem becomes much tougher because the sealer has impregnated into inside of the stone
and be integral of it.
To save troubles, if a sealer for a black granite is requested, for sure, it’s better to test prior to applications to all.
Basic steps for sealing black granite are:
1. Wash the entire surface till it’s clean and dry.
2. Brush or wrap the sealant evenly on the surface.
3. Allow the stone to absorb sealer for 2-5 minutes. Up to 10 minutes in some cases.
4. DO NOT let it dry.
5. Wipe off all excess and buff completely dry.
The most important thing is don’t let the sealer dry on the surface. Otherwise, it will lead to hazy residues.