| METAL
SURFACE PREPARATION 
The structural steel portions of all MARCO Products except as noted
below are passed through an eight wheel WHEELABRATOR Chamber prior to painting. The
resulting steel shotblasting produces a perfect surface for paint adhesion. Following
abrading, metal surface will meet Steel Structures Painting Council (SSPC) Specification
No. SSPC-5P6-63 - Commercial
Blast Cleaning.
(Products not abraded include Idler Rolls with Bearings, Power
Transmission Components, Electric Motors. Conveyor Belt. etc. Further. plated or
galvanized components such as Handrail. Walkway Decking, Housing and Fasteners are not
abraded.)
URETHANE PAINT SYSTEM
After abrading to "Commercial
Blast Cleaning" specifications, a two-component urethane coating is applied by
electrostatic-airless spray equipment to ensure maximum coverage at a 2.5 to 3.0 mil
dry film thickness with minimal runs or sags. Two-component urethane paints are recognized
as the finest protective coatings available for equipment subjected to physically and
chemically aggressive environments. Additionally, a rust inhibitive pigment has been
incorporated into the paint, thereby minimizing corrosion.
DETAILED DESCRIPTION -
SURFACE PREPARATION SPECIFICATIONS
The following is a quotation from Steel Structures Painting
Council Manual. Volume 2.
"SURFACE PREPARATION
SPECIFICATIONS"
SSPC-SP 6, COMMERCIAL BLAST
CLEANING
Blast cleaning until at least two-thirds of each
element of surface area is free of all visible residues. ( For rather severe conditions of
exposure.)"
FURTHER GENERAL COMMENTS
TAKEN FROM SSPC MANUAL, VOL. 2.
"SSPC-SP 6. COMMERCIAL BLAST
CLEANING"
Commercial blast cleaning is used as a method of
surface preparation when it is felt that blast cleaning is necessary but the high cost of
blast cleaning to White Metal or even to Near-White rules out their use. (cont.) |
|
(continued)
This method of surface preparation will result in a high degree of cleaning that will lead
to long life of practically any paint system. It is believed that commercial blast
cleaning will suffice for the majority of cases where blast cleaning is believed to be
necessary. When conditions of exposure will be rather severe. commercial blast cleaning is
recommended as the method of surface preparation..
AMOUNT OF PROFILE
"Depth of Profile" or
"Depth of Etch"- the dimension in mils from top of "peak" to bottom of
"valley". Under standard procedures a profile of approximately 1.5 to 3.0 mils
is developed while producing "Commercial Blast Cleaning Specifications."
CODE COMPLIANCE
MARCO Products comply with the following Codes:
1. Steel Structures Painting
Council-Specification No. SSPC-5P6-63. "Commercial Blast Cleaning:'
2. American National Standards
Institute-Specification No. ANSI A59. 1-1972.
3. National Association of Corrosion
Engineers Specification No. 5.1.3 NACE No.3.
DESCRIPTION
OF WHEELABRATOR EQUIPMENT
1. Chamber size - 12' -
6" wide x 15' - 9" high x 29' - 7" long.
2. Throat Opening - 4' - 4" x 8' - 0'
(Maximum material "pass through" is 3' - 0" x 6' - 0"). This allows
all products (except Hoppers and wide 601 terminals) to "pass through" after
welding-thus cleaning all welds. Components of weldments too large for 3' - 0" x 6' -
0" throat are abraded prior to welding.
3. Centrifugal Wheels-(8) wheels with 20 HP
each (total 160 HP). Where all (8) wheels are in operation, they will throw 256,000 lbs.
of steel shot per hour.
4. Wheelabrator location - located
immediately ahead of Paint Line. Material is, therefore, painted immediately after being
abraded. |
