Protection of Strain Gages Installed on a Crank Shaft
Strain gages mounted on the end of a crank shaft should be protected from oil splash; but the type of protection recommended depends on how hot the shaft might get. If under 200°F, a fully cured layer of M-Coat C with M-Coat B as a secondary coating is an excellent choice. Used by itself, M-Coat C will swell with oil absorption. And M-Coat B is slightly conductive to ground, so it must be insulated from the gage. The combination is perfect.
For applications over 200°F, GA-61 can be used with a layer of embedded FGC-1 Woven Fiberglass cloth to provide stabilization of the GA-61 over the broad temperature range. This GA-61/FGC-1 combination can also be used inside gear boxes and water passages of heads, where hot oil or coolant might be encountered.