Graco VPM 12, Instructions Manual

Page: 8 / 88

A (Red) and B (Blue) Components
8 313875J
Moisture Sensitivity of
Isocyanates
Isocyanates (ISO) are catalysts used in two component
foam and polyurea coatings. ISO will react with moisture
(such as humidity) to form small, hard, abrasive crystals,
which become suspended in the fluid. Eventually a film
will form on the surface and the ISO will begin to gel,
increasing in viscosity. If used, this partially cured ISO
will reduce performance and the life of all wetted parts.
NOTE: The amount of film formation and rate of crystal-
lization varies depending on the blend of ISO, the
humidity, and the temperature.
To prevent exposing ISO to moisture:
• Always use a sealed container with a desiccant
dryer in the vent, or a nitrogen atmosphere.
Never
store ISO in an open container.
• Keep the pump wet cups filled with IsoGuard
Select
®
, part 24F516. The lubricant creates a bar-
rier between the ISO and the atmosphere.
• Use moisture-proof hoses specifically designed for
ISO, such as those supplied with your system.
• Never use reclaimed solvents, which may contain
moisture. Always keep solvent containers closed
when not in use.
• Never use solvent on one side if it has been contam-
inated from the other side.
• Always lubricate threaded parts with ISO pump oil
or grease when reassembling.
Changing Materials
• When changing materials, flush the equipment mul-
tiple times to ensure it is thoroughly clean.
• Check with your material manufacturer for chemical
compatibility.
• Most materials use ISO on the A (Red) side, but
some use ISO on the B (Blue) side. See the follow-
ing section.
A (Red) and B (Blue) Components
IMPORTANT!
Material suppliers can vary in how they refer to plural
component materials.
Be aware that when standing in front of the manifold on
proportioner:
• Component A (Red) is on the left side.
• Component B (Blue) is on the right side.
For all machines:
• The A (Red) side is intended for ISO, hardeners,
and catalysts.
• The B (Blue) side is intended for polyols, resins, and
bases.
NOTE: For machines with material volume ratios other
than 1:1, the higher volume side is typically the B (Blue)
side.