Observation

(a)        -           Red lead primer;
-           Calcium plumbate primer;
-           Zinc chromate primer

-           Metallic lead primer;
-           Red oxide primer;
-           Zinc rich primer

-           Alkyd-based aluminium primer;
-           Acrylic primer;
-           Pink wood primer

-           Aluminium wood primer;
-           Lead free or leadless primer;
-           Etch primer;
-           Lead based primer;
-           Alkaline resisting primer;
-           All purpose, universal/multi-surface primer;
-           Quick-drying acrylic metal primer;
-           Preservative primer;
-           Stabilising/solution primer.

(b)        (i)         Pre-treatment
It is a method of coating metal before painting to improve the durability of paint by ensuring better adhesion and resisting corrosion.

(ii)        Galvanizing
A zinc coating applied on iron or steel to protect it from corrosion.

(iii)       Mill scale       

• A thin skin layer of iron oxide which covers the surface of steel when it leaves the rolling mill.
• A form of iron oxide which adheres tightly to the new metal in a laminated structure in course of time it gets loose and flakes providing an unstable basis for a paint system.

                       
(iv)       Acid pickling
-           A method of treating iron or steel by immersion in diluted acids thus protecting it from corrosion.
-           A process of removing rust from steel by immersing it in a bath containing acid solution.