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SERVICE MANUAL
Repair Kit KK-4058-1
I M P O RTA N T: B e f o r e u s i n g t h i s
equipment, read all safety precautions and
instructions. Keep for future reference.
DESCRIPTION
The MBC-ZINC-W spray gun is intended
for use with the new waterborne, zinc rich
protective coatings. MBC-ZINC-S is used
for solvent based zinc coatings.
The MBC-ZINC-W has all the features
of the standard MBC-510 and consists
of spray gun body and removable
sprayhead. MBC-ZINC-W differs in the
following components.
Leather packings
Heavy duty needle spring
Acetal copolymer construction air cap
Fluid tip with composition insert
The MBC-ZINC-S is set up for solvent
based ZINC and has the same features as
the MBC-510. The MBC-ZINC-S includes:
Leather Packings
Heavy Duty Needle Spring
MB-4039-64HD Air Cap
Standard Fluid tip and needle
T h e s e c o m p o n e n t s h a v e p r o v e n
very effective in handling the unique
characteristics of waterborne zinc rich
coatings. By using these components,
the user will insure the longest and most
reliable operation before major repair is
required.
HANDLING OF ZINC COATING
Some zinc rich formulations can require
up to 20 lbs. of dry zinc per gallon of
liquid. Care must be taken when adding
the zinc to insure complete suspension
into the liquid. Mechanical agitation
must be used when mixing, and during
application, to prevent agglomeration and
settling of the zinc particles. These larger
clumps will interfere with needle seating
and cause premature wear and leakage to
the tip or needle.
Zinc rich formulations have limited pot
life. Once the zinc is added, the liquid
slurry begins to increase in viscosity.
Material should be used within 3-4 hours
after mixing. If material is applied out-
of-doors, viscosity will increase faster
as a result of heat buildup caused by
environmental conditions.
Zinc solution – Follow manufacturers
directions for mixing zinc powder into
solution. Make sure adequate mechanical
mixing is observed during and after zinc
is mixed into liquid.
These instructions are found on both
container label and Technical Data Sheets.
In addition to specific recommendations
on handling the zinc, suppliers also have
recommendations concerning operating
pressures, air and fluid hose length
and size.
GUN OPERATION
The MBC-ZINC guns are supplied with
a D (.086”) size fluid tip. Extensive field
testing of the various zinc formulations
conclude that the use of smaller tip sizes
require elevated fluid pressures, which in
turn, increase the tendency of needle seat
interference. These higher fluid pressures
also cause the liquid material to pack out
when the gun is triggered off. Lower fluid
pressures help minimize both conditions.
After first mixing, a fluid pressure of
approximately 15 psi should provide
satisfactory flow rates for normal
production speeds. A reduction in flow
output will be experienced as the viscosity
increases and fluid pressures will have
to be increased. Under most application
conditions, atomizing air in the range of
50 psi will be satisfactory.
Packing operation – The packing set
consists of 3, pre-lubricated leather
packings. Packing tension on needle is
factory set. Lubricate packings twice daily
by adding a few drops of •SSL-10 gun lube
to the needle shaft. Retain proper packing
tension to allow smooth needle travel.
This will insure minimal needle shaft and
packing wear.
CLEANING
The fluid hose interior and gun fluid
passages should be cleaned immediately
after each zinc batch is used. Exterior
metal surfaces of the gun body and
head should be wiped clean before
any accumulation is allowed to dry.
Waterborne zinc in its dried state will be
extremely difficult to remove from any
metal surface.
MBC - ZINC SPRAY GUN
The DeVilbiss air cap GTI-1-100L, is
constructed of Acetal copolymer. The
zinc will not adhere to its surface. If
zinc is allowed to dry, the film can be
simply removed with a fiber brush or by
soaking the cap in water. When the cap
is removed, always wipe off the fluid tip
exterior surfaces to prevent any zinc build
up from drying.
PREVENTIVE MAINTENANCE
The MBC-ZINC spray gun is designed
to provide the user trouble free service
applying this unique protective coat ing,
with only minimal care and maintenance.
There are certain steps the user can take
to insure trouble-free service.
1.Never immerse or soak the entire spray
gun in any liquid. These liquids are
generally contaminated and can foul
interior components and passages.
Immer sion over long periods can also
dilute and remove lubricants necessary
for smooth operation. Lubri cate gun
components daily as indicated.
2. Mix dry zinc into solution using a
mechanical agitator. Maintain agitation
during application.
3. Mix only the amount to be used in 4
hours or less.
4. Refrain from using excessive fluid
pressures. A range of 15-30 psi should
be satisfactory during the 4 hour
period of application.
5. Avoid longer than 25 ft. lengths of fluid
and air supply hoses to the gun. Air
hoses should be 5/16” I.D. minimum.
6. Do not allow zinc to dry on any interior,
metal fluid passage in the gun or hose
fittings. An appropriate cleaning agent
should be used to purge the system as
soon as a batch is used up.
7. Use a cleaning brush (see Accessories)
to clean the air cap. Do not use a wire
brush. Also avoid using metal objects
such as drill bits to clean air hole jets.
•Safety Data Sheet available upon request.
MBC-ZINC-W
(FOR WATERBASED INORGANIC ZINC)
MBC-ZINC-S
(FOR SOLVENTBORNE ORGANIC ZINC)
