How do Salt Crystals Form?Salt is mostly sodium chloride (NaCl). You may also see it called halite. Salt crystals generally form a cubic shape.
One way that salt crystals form is from salt that has been dissolved in water forming a solution, a typical saltwater pool. When water begins evaporating from the solution, at some point there is simply not enough water left to keep the sodium and chlorine ions from joining together, so salt crystals begin to form. Rock fracture and cracking occurs as salt crystals grow and exert pressure.
Crystal growth is affected by four naturally occurring factors. It's important to understand what causes crystal growth in order to have an effective solution for preventing it. Here are the four basic reasons in order of significance:
Amount of dissolved salt
Amount of space
In a saltwater pool situation the salt crystal growth rate has an important influence on the pattern and intensity of rock damage. The growth rate is heavily determined by evaporation.
The RockSteel Solution
The rockSteel process will stabilize or eliminate the rock fracturing, cracking and breaking (“decay”) being caused by the growth of existing salt crystals in the stone. In most situations, rockSteel will:
RockSteel forms a barrier on the stone, it molecularly forms a bond with the stone; the barrier prevents further saltwater or air from reaching into or touching the rock surface…the surface is sealed.
Existing rock erosion can be in many stages; from extensive to just beginning. Damage is normally greater where the rock is very porous (weak) or has received more saltwater.
The steps in the Process are as follows:
What's Going On Beneath The Barrier?
Once the surface has been sealed, no additional saltwater can seep into the stone. Remaining, trapped underneath the barrier’s surface, is some volume of saltwater and salt crystals in various sizes and stages of growth. Crystal size will vary from small to large.
The barrier will dramatically minimize evaporation, slowing, delaying, and often eliminating immediate crystal growth. The barrier cannot eliminate evaporation. However, the evaporation process is now greatly impeded.
Evaporation is the key process in the formation and growth of salt crystals. It is the process by which water is converted into a vapor creating the formation of salt crystals. Impeding or eliminating evaporation reduces or eliminates salt crystal formulation and growth. Remembering our science class, water like all liquids, is held together by intermolecular forces. As the temperature is raised, the molecules in the water move more vigorously, and in increasingly high proportion have sufficient energy to escape from their neighbors. Evaporation is therefore slow at low temperatures but faster at higher temperatures. In an open area like a pool, the molecules escape from the vicinity of the water, and there is an on-going, positive flow of molecules from the water into the atmosphere. Water is turned into a vapor with the result being less water in the pool. In an area such as the interior of a rock evaporation also continues in the same manner.
The effect of rockSteel on evaporation
The barrier formed by rockSteel is similar to placing a cover on a pool. As we all know, the pool cover greatly reduces and minimizes evaporation. This same affect is created by rockSteel’s barrier – we have placed a cover over the rock.
Some growth can continue
Growth can continue, albeit much, much slower and then only for a period of time. It is important to realize that in some areas, the added growth will be “the straw that broke the camel’s back”, just enough to cause the rupture of a piece of stone. When this happens, the specific area needs to be cleaned, preferably pressure washed again, and rockSteel reapplied. This is most likely to occur where the erosion is extensive but can occur where the crystal growth has reached the size where its next increment of growth creates enough added pressure to break a piece of the stone.
Limited growth of crystals can continue after application of the barrier, however, crystal growth will dramatically be minimized and at some early point, stop because the level of energy needed for evaporation to continue will be too diminished to support evaporation.
With salt crystal growth minimized and/or eliminated, and no new saltwater entering the rock, the decay and erosion of the rock will have been stabilized.