Before applying a new coat of sealant, take the "water test." Take 1/4 cup of water and pour it on the countertops. If the water stays "beaded" on top, your counters should not need sealant. However, if the water appears to seep into the surface or you notice a dark spot, you should seal the granite.
A properly sealed countertop repels water, causing it to bead up on the surface. But if it isn't sealed in a place where water is constantly used – like the kitchen and bathroom – water will penetrate the stone and leave behind water marks and a dirty appearance.
No, not all granite countertops need a sealant. Sometimes, granite comes sealed from the manufacturer. For instance, here at Atlantic Granite & Marble, we use a 15-year lifetime sealer. Granite is an igneous rock that contains various natural stone materials that can be prone to stains and scratches.
In a spray bottle, create a 50/50 mixture of water and alcohol, then spray the entire surface with the mixture and wait for 5 minutes, then with a soft cloth wipe everything off the counters and let it dry.
The acids contained in these cleaners will degrade the sealant and can leave unsightly stains on the countertop. That means those Clorox disinfecting wipes (which contain citric acid) that make cleanup so easy are actually quite bad for your granite's seal.
Since granite countertops have a sealant on them to keep them shiny and stain-resistant, you want to avoid using anything too acidic or basic on the granite. Frequent use of vinegar, Windex or bleach will dull the granite and weaken the sealant.
Apply sealant to countertops
Use a spray bottle, cloth, or brush to apply it. The entire surface should be damp, but not soaked. Give the sealant time to absorb into the stone. On average, it should take about 20 minutes, but take care to read the directions on the bottle of sealant for specifics.
The truth is that most (but not all) granite countertops need to be sealed. There is a simple test to see if you need to seal the countertop you're choosing and determine when your countertop needs to be resealed (typically every 5-7 years, depending on the sealant).
Granite is a Porous Material
Brand new granite counters often have a sealant applied during installation. However, this sealant wears off over time, which is why reapplication is so crucial.
The answer is yes, you can permanently seal your granite and that will give you a completely maintenance-free countertop.
Note: Some experts will recommend sealing granite countertops every “6-12 months” or “3-5 years”, but there is no hard and fast rule.
Granite is Heat Resistant
Placing a hot pan on a well-maintained granite slab will not cause it to crack or weaken. Just remember that repeatedly placing a very hot pan on the same spot may cause granite to discolor.
Sealed granite countertops are much less likely to absorb water, however if water is left on your countertop for long periods of time, it can cause a darker spot.
The fact is, the porous nature of granite can lead to absorption of water through tiny holes that are not visible to the naked eye. Just a small amount of water left to dry on your countertop may not cause a problem but if it is left for a very long period of time, it could cause the counter to darken in that one spot.
Wait 24 Hours Before Polishing
If you want to follow up sealing with polishing to bring out your granite's natural luster and color, make sure you wait at least 24 hours after sealing. Granite polish should only be applied once the seal has cured and the surface is dry and clean.
If it beads up, you have a secure seal. If after a few minutes the water has soaked into the granite, then it's time to reseal the stone. DON'T: Use harsh or abrasive cleaners and sponges. Windex; acidic cleaners, like vinegar, lemon, lime; or anything with ammonia or bleach should be avoided.
It's important to understand that an impregnating sealer should not alter the color or finish of the granite counter. It won't make a polished surface dull, or a matte counter shiny. It's invisible when dry.
Choosing the Right Sealant is Essential
For this reason, look for products in the class known as impregnating stone sealers. They are chosen by professional contractors for sealing granite, marble, and slate countertops. The top-rated product in this class is Tenax Hydrex Impregnating Stone Sealer.
You might need a polishing powder. Buy a polishing powder designed for natural stone countertops. You'll generally have to mix the powder with water to form a paste. Then “polish” problem areas with a soft cloth.
I found that the “drying oils” – hemp, tung, and walnut all held up well as countertop sealers. They work best on dark or warm tones stones since they can yellow light-colored stones. Walnut oil is very light in odor and in natural VOCs. They all repelled water perfectly.
You should not use Lysol on your granite countertops, backsplashes or vanity tops. The cleaner contains harsh ingredients that can cause your sealer to lose its effectiveness. In specific, scents such as lemon contain citric acid, so you need to keep away from those.
Don't use harsh chemicals, acidic cleaners, or abrasive scrubbing tools: Stick with warm water, mild dish soap, and a soft microfiber cloth. Steer clear of vinegar, which can dull the granite and weaken the sealant—though there are plenty of other ways to clean with vinegar around the house!
However, vinegar should never be used on your granite countertops. Vinegar is made up of acids that can severely harm your granite. Even if it is diluted, vinegar may still leave acids on your granite countertops. This can cause your natural stone countertops to etch.