This paper concerns the many uses of these two polymers in conservation. Although this information is paper conservation oriented, it may very well be that it can be useful to conservators in other fields.

 

Methylcellulose (MC) and sodium carboxymethylcellulose (sod. CMC) have many other uses besides those in conservation. A brief rummage through your medicine cabinet may come up with such products as toothpaste, laxatives, or diet pills each of which may contain either MC or sod. CMC. Other products include ice cream, water-based paints, detergents and a variety of paper products to name but a few. Characteristics which make them useful are: high viscosity in low concentrations, defoaming abilities, surfactant, and bulking abilities. They are not toxic and do not promote allergic reactions in humans. At the end of this paper, I have given more technical information on the composition of the various MCs and sod. CMCs.

 

These cellulose polymers can be purchased in grades ranging from coarse to fine particles and in varying viscosities. In solution, Hercules CMC 7H and Culminal (MC from Talas) are quite clear while Cellofas B3500 from Conservation Materials is hazy.

 

The easiest way to make up any of the MCs or sod. CMCs is to measure out the desired quantity of the powder, fill a blender with the right amount of deionized or distilled water, turn on the blender to the lowest speed, and pour the powder in a steady stream into the vortex. As soon as all of the powder is in the water, turn off the blender. Over-blending can result in a loss of viscosity. No preservative is necessary as long as purified water is used and the storage container is airtight. After blending, it is best to leave the solution at least one hour before using.

 

Most conservators regard the MCs and sod. CMCs primarily as adhesives. We will see in fact that they have many other uses, but let's start with their adhesive applications. First may I say that neither MC or sod. CMC alone is really strong enough to be used as an adhesive when a great deal of stress on the bond is encountered such as in tear repairs or hinges.