Selecting Granite Counters - Stain resistance, sealing and etching
Granite, a nearly impregnable material, but is it? Homeowners worry about selecting the best granite counter that will
resist damage from spills and stains or question whether and when to seal the granite countertops.
The following common granite counter questions are addressed in this article:
How do I pick the best, most stain resistant granite?
How do I know if the granite I like will require sealing or resist acidic spills & etching?
How do I know when to re-seal my granite?
With the test below you can determine which granite will best resist staining and etcing, benefit from a seal or when to re-seal your counters.
You will need the following materials to test your granite counter:
Water – no permanent harm or stain will evaporate
Mineral Oil – no permanent harm or stain will evaporate
Lemon Juice – use only on a sample throw-away as it may etch the stone.
Soft absorbent cloth or sponge
How to test your granite counter:
samples of the granite you wish to use as a countertop material
the samples on a flat surface with the polished side up
a drop of lemon juice, water and mineral oil on each sample.
10 minutes wipe each granite sample dry with an absorbent cloth
the granite samples
How to read the results of the granite counter test:
finish is dull or damaged (etching) by the lemon juice, then your ‘granite’ has
calcite and no sealer can protect it. read more
water leaves a dark area, your granite is absorbent and a sealer
can help to protect it.
mineral oil leaves a dark area, your granite is susceptible to oil and
a sealer can help to protect it.
If no darkening or etching occurs, your granite will not take a sealer, and will be nearly impregnable.
Granite etching: If you are concerned regarding
etching, a permanent damage to your stone, then you want a stone without
calcite. Calcite etches when exposed to acids. Sealers do not protect against
etching. That means orange juice, lemon juice, grape juice, soda, etc... Any
acidic spill on calcite will immediately begin to degrade whether it is sealed or not, because of the chemical reaction between calcite and acid. If you’ve heard
about etching on a countertop, this is the result of a acid and calcite reaction. Not all stone has calcite in it. Testing a sample of your prospective granite countertop purchase with lemon juice will reveal whether this selection will resist these spills. Test only a sample as this may damage countertop finish.