Download PDF version (187.8k) Log In or Register to view the full article as a PDF document.
Mixing Grout Grout is stronger when mixed slowly by hand, but power mixing can be done with a paddle chucked into a slow-speed (300 rpm max.) drill (Figure 3). Figure 3. Grout is best mixed slowly by hand. For larger quantities, mix at slow speed with a paddle mixer chucked into a 1/2-inch drill. As the grout is applied, remix every five or ten minutes to keep the grout workable.Figure 4. To ensure a precise liquid-to-powder ratio, the author recommends using a balance-beam scale for dry powder and large-scale measuring cups for the liquid. For larger quantities, he uses an "idiot bucket" — a plastic pail with a hole drilled in the side through which excess water can drain.Figure 5. The consistency of the grout mix should be stiff enough to hold its shape, but fluid enough to fill joints when pressed into place with a rubber trowel. Mix subsequent batches in a clean bucket to keep the old grout from causing the fresh batch to set up too fast. If the grout is too wet or dry, add and mix ingredients as needed. As the grout is being applied to the tiles, remix the grout in the bucket about every five or ten minutes. Like the rotating drum of a transit-mixed concrete truck, frequent mixing keeps the grout soft, workable, and ready to use. For subsequent batches, use a clean bucket so that old grout does not force the fresh batch to set up prematurely.