Trowel and Knife Application

Some mortars or putties or mastics may be applied in thick coatings or blobs or zones, on rough substrates with a trowel or knife (Fig. 3). This is frequently used in construction and civil engineering. 

The mortar or putties must be very thick, at least 500,000 mPas to avoid sagging on walls (in fact, for such thick products, viscosity is no longer significant, and instead penetration or sag resistance are measured). 

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