The document discusses paint composition and the painting system used for Indian Railways coaches. It notes that paint is composed of pigments, additives, binders, and solvents. The painting system for LHB coaches uses an epoxy-polyester-polyurethane system for its durability and resistance to corrosion. The painting procedure involves surface preparation, primer application, putty application and rub-down on joints, and a final polyurethane primer application.

1. LHB PAINTING

2. WHAT IS A PAINT…
Physically, paint is a mixture of four
important elements:
Pigments, Additives, Binders and
Solvents.
Pigments render color and opacity to
the paint.
Additives endow the paint with special
properties such as resistance to fungus,
rust etc.

3. WHAT IS A PAINT…
Binders: hold the paint together
and also bind it to the surface being
painted, thus promoting durability.
Solvents:- give a paint its flowing
property, enabling brushing/rolling
on a surface.

4. PURPOSE OF PAINTING…
 Different paints have specific
properties that prevent, or at least
delay the rusting and corrosion by
forming a protective layer around
the substrate.
 Different colour schemes provide
asthetic look to materials.

5. PAINTING SYSTEM IN INDIAN
RAILWAYS…
 Alkyd- Alkyd- Alkyd system
(Earlier Followed in ICF).
 Epoxy-Epoxy- Alkyd system
(Earlier in RCF for ICF type coaches)
 Epoxy- Epoxy- Polyurethane system
(Earlier in RCF for ICF type coaches)
 Epoxy-Polyester- Polyurethane
system
(In RCF for ICF & LHB coaches)

6. WHY PU PAINTING…
Alkyd painting system is:
 Less durable.
Low Gloss & Colour retention.
Less resistance to salty atmosphere.
Less resistance to ultra-violet rays.
Require frequent re-painting.
Increases effective cost of painting.

7. LHB PAINTING PROCEDURE…
(Epoxy-Polyester- Polyurethane system)
1. Surface Preparation.
2. Primer Application.
3. Putty Application on joints.
4. First & Second Coat Putty application.
5. Putty Rub-down.
6. Fine Putty Application.
7. Fine Putty Rub-down.
8. PU Primer Application.