Removing Salts from Stone Using the Poultice Rendering Process
By Frederick M. Hueston, stoneforensics.com
When it comes to preserving and restoring marble, granite and other stone surfaces, removing salts from stone is a common challenge. Salts can accumulate within the stone over time, causing damage and decay. If salts are trapped in the pores of the stone, a condition known as sub florescence, this can cause pitting and spalling. For this reason it may be necessary to attempt to remove the salts from the stone. One effective method of removing salts from stone is through poultice rendering.
Poultice Rendering involves the application of an absorbent powder to the surface of the stone. The poultice can draw out the excess salts within the stone as it dries. A poultice can consist of any absorbent powder such as diatomaceous earth, attapulgite clays, talc and even flour.
The process of rendering to remove salts from stone typically involves several steps. First, the surface of the stone is cleaned to remove any loose debris or dirt. Next, a mixture of absorbent powder and distilled water is prepared to create a paste. The paste is then applied to the surface of the stone using a trowel, creating a layer that is typically several millimeters thick.
After the paste has been applied, it is left to dry for several days. During this time, the poultice dry’s, the distilled water dilutes the salts which is absorbed into the power as it dries. Lime powders have also be used which will help to neutralize any salts within the stone, preventing further damage and decay.
While rendering can be an effective method for removing salts from stone, it is important to note that it is not suitable for all types of stone. Some types of stone, such as sandstone, can be too porous to effectively hold the poultice. In these cases, alternative methods may need to be used to remove salts.
In addition, the use of rendering to remove salts from stone should only be undertaken by professionals with experience in historic preservation. Improper application of the poultice can result in further damage to the stone, which can be costly and difficult to repair.
Overall, rendering can be a highly effective method for removing salts from stone.
Removing Salts from Stone Using the Poultice Rendering Process
Removing Salts from Stone Using the Poultice Rendering Process
By Frederick M. Hueston, stoneforensics.com
When it comes to preserving and restoring marble, granite and other stone surfaces, removing salts from stone is a common challenge. Salts can accumulate within the stone over time, causing damage and decay. If salts are trapped in the pores of the stone, a condition known as sub florescence, this can cause pitting and spalling. For this reason it may be necessary to attempt to remove the salts from the stone. One effective method of removing salts from stone is through poultice rendering.
Poultice Rendering involves the application of an absorbent powder to the surface of the stone. The poultice can draw out the excess salts within the stone as it dries. A poultice can consist of any absorbent powder such as diatomaceous earth, attapulgite clays, talc and even flour.
The process of rendering to remove salts from stone typically involves several steps. First, the surface of the stone is cleaned to remove any loose debris or dirt. Next, a mixture of absorbent powder and distilled water is prepared to create a paste. The paste is then applied to the surface of the stone using a trowel, creating a layer that is typically several millimeters thick.
After the paste has been applied, it is left to dry for several days. During this time, the poultice dry’s, the distilled water dilutes the salts which is absorbed into the power as it dries. Lime powders have also be used which will help to neutralize any salts within the stone, preventing further damage and decay.
While rendering can be an effective method for removing salts from stone, it is important to note that it is not suitable for all types of stone. Some types of stone, such as sandstone, can be too porous to effectively hold the poultice. In these cases, alternative methods may need to be used to remove salts.
In addition, the use of rendering to remove salts from stone should only be undertaken by professionals with experience in historic preservation. Improper application of the poultice can result in further damage to the stone, which can be costly and difficult to repair.
Overall, rendering can be a highly effective method for removing salts from stone.
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