Painting procedure complying to C5
Below procedures for coating Jotun’s special Marine paint for C5 Environment using wet
coating process.
The surface of the impeller is first cleaned with a hard bristled brush to clear away
any debris that is present.
Then it is cleaned with Zinc Chromate to remove any oily residue.
Then the surface is carried with light Sanding.
The parts are then thoroughly rinsed with water at pressures of 2000-5000 psi at a
flow of 4-14 gallons per minute and then dried.
Parts are then sprayed with high build Primer, Jotun Barrier 80.
Parts are then carried with light Sanding and smoothing of the surface.
Then an intermediate coat is sprayed with Jotun Penguard Express MIO.
Parts are then carried with light Sanding and smoothing of the surface.
Then the Top coat is sprayed with Jotun Hardtop XP.
Curing is done after every coat of primer/paint by allowing painted parts to air dry in
controlled and closed drying booth. This helps to achieve a uniform surface without
any blisters / air bubbles.
The overall process achieves a uniform coating thickness of around 250-300 micron, with
recommended hardness and toughness of the coat.
If a higher flake thickness is required, parts are again carried with light Sanding and
smoothing of the surface, following another Top coat of Jotun Hardtop XP.
Note:- In general parts like fan shafts, drives, motors, Belts, Misc. hardware and small
sized Radial wheels are not coated.
The performance of both the above processes meets specifications below
1. Gloss (DIN 67530) The minimum gloss level on delivery is 65% +/-5% when measured at 60
deg C incident light.
2. Adhesion (DIN 5315 1/ISO 240-2 MM) Cross Hatch rating GT 0 (100% adhesion).
3. Impact Resistance (ASTM 2794) More than 20in/Lb without film cracking.
4. Erichsen Cupping Test (DIN 53156/ISO 1520) Cylindrical Mandrel diameter.
5. Film Hardness (DIN 53153/ISO 2815) Indentation resistance acc. To Buchholz: 80 – 115.
6. Mortar Resistance (ATSTM c207) After 24 hours at specified conditions mortar is easily
removed from the coating resulting neither in loss of adhesion nor in surface marring.
(Note: Mortar should preferably be removed as soon as possible if spilled on coated
surfaces.)
7. Drilling Milling/Sawing Test: No flaking of coating.
8. Resistance to Humid atmosphere: Containing SO2 Test according to DIN 50018 and ISO
3231 – 1974 with 0.21202 per cycle. After 30 cycles – ie total of 720 hours of direct SO2
exposure – no blistering or loss of adhesion occurs. No noticeable change in colour or
gloss.
9. Resistance to Humid Atmosphere (DIN 50017) No blistering or loss adhesion after 2000 hrs
continuous exposure at 100% RH and 40 deg C.
10. Resistance to Water (ISO/R 1621-1971) No blistering or loss of adhesion after 100 hrs in
deionised (but not aerated water and at 40 deg C.
11. Weather Resistance (ISO 12944-1) No chalking and color stability after more than 2000
hours testing in sun test at 40 deg C.
12. UV Resistance (Xenon Test) Excellent color stability. Dry heat resistance 2 hours at 150
deg C.
