In any paint or coating job or contract there are three golden rules to follow before the actual application of the correctly chosen product.
These are: preparation, preparation and preparation.

Another important point to remember is that any paint or coating is only as good as the substrate onto which it is applied.
ANOTHER THING – Take due care when washing anything with acid.

Metal substrates (Excluding galvanized steel)

These must be cleaned thoroughly by removing all old paint, grease dirt, rust and any foreign material.
Use whatever means are available to you, such as -sand paper, sanding machines, (Belt sander, orbital sander etc.) sand blasting, wire brushes, high pressure sprayers, paint strippers, etc.

If rust is removed and there is a  possibility that small amounts are left behind  apply a rust converter to any suspect areas.
Once this has been done and the rust converter has had a chance to act, apply a single coat of Dead-End or Primero or Dead-End AND Primero

Once the primer or undercoat has dried now apply your final coat of chosen paint. Kling-On or Body-Guard are  excellent choices.

Galvanized steel
Remove all old paint, dirt etc. by chemical or mechanical means as described above.
Thoroughly clean the surface with a high pressure spray or other means at your disposal.
Remove  ALL visible rust by mechanical means, apply a rust convertor if necessary to suspect areas.
Coat the surface with Dead-End or Primero.

Allow to dry then apply the final chosen coating such as Therma-MastaAqua-Thermkling-OnRoof-MastaBody-Guard etc.

Wooden substrates
All old paint, dirt, grime etc. must be removed by mechanical means or with paint strippers etc.
The surface must be sanded smooth and the subsequent “dust” removed with a cloth, brush etc.
Apply a primer such as Fibre-Guard.
Allow to dry. Apply the final coat of choice which could be a second coat of Fibre-Guard.

Plaster substrates
If the plaster is new, clean and stable, apply a primer or undercoat such as Con-Seal or Water-Proof.
If the plaster is old make sure it is clean, dry and stable, remove old paint, dirt, grime etc. before applying Con-Seal or Water-Proof.
Wait for the primer to dry before applying the final coating of choice such as Kling-On

Asbestos fibre substrates
The entire roof should be repaired first, by repalcing loose or missing roofbolts (This also applies to galvanized steel roofs) patch any leaks and do general repairs.

Now you can high pressure clean the entire roof.
If no pressure cleaner is available, scrub the entire roof with a scrubbing brush, then wash with water.
All old paint, dirt, grime etc. must also be removed.

Now you can apply a primer or undercoat such as PrimeroDead-End etc.
Once this is dry apply the final coat of choice such as Roof-MastaKling-OnTherma-Masta etc.

Painted walls
Sand down with sand paper, orbital sander, belt sander etc.
Remove all dust, dirt, grime, old paint etc. Apply a primer/bonder such as Con-Seal.
Allow to dry. Apply final coat – Kling-On is a good choice.