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RTV Silicone Rubber Coatings
 



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Many materials can be used to protect strain gage installations. Perhaps none is more versatile for short-term applications than room-temperature vulcanizing (RTV) silicone rubber. The list of this material's capabilities is indeed impressive:
  Available as an easy-to-apply single-component coating with uncured consistencies ranging from a low-viscosity brush-on material for thin coats, to a medium viscosity self-leveling form for use on level surfaces, to a high-viscosity no-run paste for vertical and overhead applications.

  Cures at room temperature, yet is usable over a temperature range of -75 deg to +550 deg F (-60 deg to +290 deg C).

  Has a low modulus of elasticity that is ideal for thin or flexible structures for which coating reinforcement effects may become significant.

  Provides the installation with good protection from mechanical abuse. (Also works well for anchoring leadwires to the surface of the specimen, for most applications.)

  Provides good short-term protection from water; resists many chemicals; and can be used in radiation and vacuum environments.
In order to cure, most single-component silicone-rubber materials must absorb a small amount of moisture from the surrounding atmosphere. This moisture reacts with the material during polymerization to produce condensation by-products, commonly acetic acid or methyl alcohol. Those producing the acetic acid by-products smell like vinegar and SHOULD NOT BE USED AS A PROTECTIVE COATING for strain gages.

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