Drilling Holes

Drill Holes in intertidal rocks using a Chicago Pneumatic CP9A drill.  Drill a 5/8” diameter hole at least 7" deep.  Then widen the opening of the hole, as deep as the collar, using a 1 ¼” bit.  Center this second hole on the 5/8" hole and make sure it has the same orientation.

Pack marine epoxy around the collar and surrounding rock being careful not to glue the dynamometer in place. 

Use a turkey-baster to flush out the holes after drilling.  Screw a dynamometer into its collar and glue the dynamometer with collar into the hole using marine epoxy (see below left).  (Placing the dynamometer in the hole in this fashion will properly orient the collar). 

After you remove the dynamometer, keep the hole capped using a 1/2" threaded male plug (pictured above on the right) to prevent the hole from filling up with sand or intertidal animals.

Recording data from the Meters

            To read the meters take a measurement, with calipers, from the exposed bottom of the string guide to the rubber stopper.  Make a record of the number of the meter, the hole it was located in, and the measurement in mm.  Reading the meter is shown in the photograph below: