Catalyst-cured sealants have an advantage over
drying sealants because they are transformed from a
fluid or semifluid state into a solid by chemical
reaction rather than by evaporation of a solvent. A
chemical catalyst or accelerator is added and mixed
just prior to sealant applications. Heat may be
employed to speed up the curing process. When you
use a catalyst, you should accurately measure and
thoroughly mix the two components to ensure a
complete and even cure.
APPLICATION OF SEALANTS
Figure 14-43.Spray gun nozzle.
The application of sealants varies according to
time, tools required, and the application method.
Figure 14-42.Sectional view of typical spray gun.