Operation
12
313267W
Spray Technique
Always follow all safety procedures outlined in this man-
ual.
The standard .046 in. mixing chamber supplied with
your gun is adequate for all but the smallest and largest
applications.
To achieve the optimum spray pattern for other applica-
tions, appropriate mixing chambers are available from
Graco in seven round and six flat spray sizes. See
Kits
on page
NOTE:
Foam rise and cure times vary according to the
material and substrate temperature. Higher material or
substrate temperatures increase the rise and cure
times; lower material or substrate temperatures
decrease rise and cure times. Consult your chemical
manufacturer’s data specification sheets for their recom-
mended spray temperatures. Under most circum-
stances, both components are used at identical
temperatures.
Higher pressures and temperatures may be used to
increase material breakup, improve mixing, and speed
up rise times. With hose lengths over 50 ft (15.25 m), or
when material viscosities are high, higher material pump
pressures may be necessary.
The supply air switch assembly (D) must be opened
(pushed down towards the front of the gun) prior to
spraying to provide air for piston operation and purge air
when the piston is released.
When spraying, the gun piston may be activated contin-
uously or deactivated at the end of each stroke. A
smooth, even layer is best achieved by moving the gun
back and forth in a slow, even motion, overlapping the
previous pass by about 50 to 75 percent.
The ideal gun-to-surface distance is about 18 to 24
inches. Be sure to point the gun directly at the surface to
be sprayed. Spraying at an angle to the surface causes
the foam to be rough and generates over-spray.
