Vanadium and Manganese are naturally occurring minerals in certain seams of clay. Like soluble salts, they are released when an abundance of water must migrate through a masonry structure. In the case of NMD 80, the occurrence of stains has absolutely no relation to the cleaning process of a sound, well built wall.
The best way to keep these stains from occurring is to keep the brick covered before installation. Do not allow rain to enter the wall during construction. If these two practices are not or cannot be adhered to, allow the wall to dry thoroughly before cleaning. Any stains that occur during the drying process can be removed by NMD 80 in the normal cleaning process. Only one normal cleaning process is needed to resolve the issue. In the case of exceptionally heavy staining, a trigger sprayer or pump sprayer of OneRestore® can accompany the cleaner. During the rinsing process, any visible staining that is still visible can be immediately released with a small application of OneRestore®. Simply rinse and the regular cleaning process can continue. Troubleshooting during the cleaning has virtually no extra cost.
Regarding the issue of chemistry causing the stains, we have a simple test. Take a stained brick prior to installation and liberally pour undiluted NMD 80 on the surface. Allow the product to dry; the stains have been removed and no new staining has occurred. We have tested the scenario on a multitude of brick and have yet to see the product fail. The use of OneRestore® is not normally required when NMD 80 is used in the initial cleaning process. Over two decades of experience with the product informs us that it will remove all stains on a well dried wall. We have documented many large projects where a generally specified product is used and a large amount of staining occurs. When a wall is re-cleaned with NMD 80, the stains dissolve.
The recorded occurrences, observations and consistent test results have led us to the conclusions in this statement. The conclusions have been field tested over the past several years and have provided very accurate results.
The brick manufacturers do not put the minerals into the brick (unless added as a colorant) and are not responsible for the stains occurrence.
We have yet to experiment with moisture meters, and the industry is open to develop a standard for appropriate dryness of the wall before cleaning.