The sketch shows grouting of a hole in progress until thickening of the grout becomes necessary.

To commence the thickening process measure the quantity of grout remaining in the agitator

Thickening of the grout which is already in the lines and machinery is a frequent operation during grouting of a hole, whenever a change to thicker grout is needed as part of the grouting technique, or leaks are being attended to or rock movement is being handled.