The Granite Shield process on calcite based stones will not prevent surface etching but will reduce it about 80%.Granite Shield does have a repair kit that should etching happen if sealed with Granite Shield sealers remove etching in minutes on polished or honed surfaces. Acidic liquids, alcohol and vinegar can etch marble, travertine, limestone and quartzite if left unattended on your stone surface. Water with a lower pH level lower than 7 is considered acidic.
pH Values
Stomach acid 1 to 3
Lime Juice - 1.8 to 2
Lemon Juice - 2.3
Coca Cola - 2.5
Soft Drinks - 2.5 to 3.0
Vinegar - 2.4 to 3.4
Apple Juice - 3
Orange Juice - 3.5
White wine - 3.0 to 3.3
Red wine - 3.3 to 3.5
Drinking alcohol such as gin, rum and vodka - 3 to 6 adding Orange or Lime juice will lower pH
Tomato & Tomato Juice - 4.2
Beer - 4.5
Coffee - 5.5
Normal rain - 5.7
Milk - 6.2
Saliva - 6.3 - 6.6
Dog urine - healthy is 6.2 to 6.5
Drinking water - 6.5 to 8
Water - Under 7 is considered acidic
There is currently no penetrating sealer that can stop etching on calcite based stones. On Absolute Black granite etching causes gray rings and spots on the surface. A topical sealer is not recommended for natural stone because it blocks the pores of the natural stone then can't breathe and the top coating can scratch easy. So what happens to natural stone that can't breathe? Moisture gets trapped and can cause a chemical and mineralogical change within the stone. This action of decay in natural stone may take form of pitting, spalling, flaking and oxidation. You want your natural stone to breathe or it will disintegrate. ***Please note if quartzite was sealed we don't warranty Quartzite. Better to seal and protect the best you can. Basically anything can leave marks on Quartzite. Quartzite is a problem stone for most we have encountered. We seal it but we don't warranty it. In most cases to fix the stain or etch on Quartzite it has to be machine polished by a stone restoration company. The authorized applicator may warranty it.***
***Other than a polished granite Windex can not be used to clean the countertop, Windex will strip the sealers. On polished granite when Granite Shield sealers are applied one of the sealers is Crystasheen. Crystasheen is a permanent sealer. Kleen N Shine is the last step and makes the countertop shinier. Kleen N Shine is not permanent and needs to be reapplied if you want the countertop to be as shiny as the day it was sealed. Crystasheen is not applied to honed, leathered or calcite based stones such as marble. On calcite based stones the type of cleaners used is very important. The goal is to protect the sealant as much as possible to not etch or dull the stone. When in doubt use a neutral pH7 stone cleaner such as Granite Shield's Nustone Kleen. To refresh and reduce the chance of etching Granite Shield's Kleen N Shield should be used at least once a month and when a heavy duty cleaner is needed.***
