Dekro Paints Project Focus - Dekro Paints

Dekro Paints Project Focus

Dekro Paints were requested to provide assistance to coat the metal silos at Feedpark, Phisantekraal. The existing coating not only deteriorated beyond functionality but also did not provide any corrosion protection on the visible corrosion on the structure. Due to the various layers of coatings and adhesion issues we provided a remedial redecoration specification to Reno Roofs for treatment of these silos.

Preparation and Coating Requirements:

Remove all loose and friable paint by mechanical means to expose ferrous oxide. Mechanically clean to St.2. preferably using pneumatic descaler where required.

Feather all edges and build up removed corroded mild steel by applying Dekster Epoxy Putty Lite (A lightweight, non-slumping epoxy / polyamide of paste consistency designed to adhere to damp surfaces and can be smoothed with water.

Apply a stripe coat of Tuffcoat at 150µ on all rusted affected areas cleaned to St2 (Swedish Standards)

Apply first coat of Hydrolock Primer at and allow 2 hours drying time (Max 3 days)

Apply second coat of Tuffcoat at 150µ and allow 12 hours drying time (Max 3 days)

Apply two coats of Unymarine at 30 – 50µ and allow 4 hours drying time between coats

As far as preparatory work is concerned, it has been shown that the effective life of a paint coating of perfectly clean steel, free from rust and scales, may be up to five times longer than that of the same coating applied to imperfectly cleaned steel. The traditional manual methods of preparing new and old steelwork for painting by chipping, scraping and wirebrushing are far from ideal, as they cannot remove lightly-adherent scale nor deal effectively with rust on pitted or rough surfaces. Alternative methods such as pickling, grit blasting, flame cleaning and chemical derusting are either not practical on erected steel, or may be considered too expensive. It should be realised that the higher initial cost would be more than offset by a reduction in maintenance costs by the longer life of the paint coatings.

For general use on iron and steel, primers incorporating rust-inhibitive pigments must be used, for example, zinc phosphate, metallic zinc, etc., in various binders such as the conventional linseed oil, or alkyd resins, or epoxy resins, etc. Too often cheap and inferior primers are used containing less than the minimum quantities of anti-corrosive pigments to be effective. Such paints do more harm than good as they must first be removed before a systematic and effective painting operation can be carried out.