TM 5-822-11/AFP 88-6, Chap. 7
specific temperature for application into a joint or
the sealant and the oil bath should be calibrated
crack. If the sealant is installed using an
and located where they can be easily read. The
application temperature that is too low, adequate
melter should be designed to circulate the sealant
bonding to the joint or crack face will not occur,
through the delivery hose and return to the inner
and in some cases, the sealant will not cure. This
kettle when not in use.
is particularly true for hot-applied sealants that are
(2) Liquid Hot-Applied Sealing Equipment.
liquids at room temperature. Some liquid sealants
The equipment used for heating and installing the
require heat to chemically change the sealant
liquid hot-applied joint sealant materials is
allowing it to cure. If the correct temperature is
equipped with a reservoir tank that is not main-
not achieved during application, the sealant will
tained at the application temperature. The sealant
have to be removed from the joint. If the sealant
is drawn from this tank and is pumped through
is installed using an application temperature that is
tubes in a heated oil bath which brings the sealant
too high, the sealant will be damaged and can lose
to the application temperature. Once at the appli-
its resiliency and bonding ability. Therefore, one
cation temperature, the sealant is inserted into the
of the most important characteristics of a melter is
joint. This type of equipment is not designed to
its ability to heat the sealant to the proper
recirculate the sealant.
temperature and maintain that application
b. Cold-Applied Sealing Equipment. The type of
equipment used to install cold-applied sealants will
(1) Solid Hot-Applied Sealing Equipment.
depend upon the type of sealant, two-component
The equipment used for heating and installing
or single component, hand mix or machine mix.
solid hot-applied joint sealant materials (fig 5-2)
All applicators should be equipped with nozzles
must be equipped with a double-boiler, agitator-
that are shaped to allow the sealant to seal the joint
type kettle to prevent localized overheating.
reservoir from the bottom to the top.
Thermometers for indicating the temperature of