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).
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
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
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.