Pre-coated roof sheets

Many new developments feature homes with pre-coated roof sheets. In some instances the colour of these roof sheets fades within a short space of time, and home-owners need to re-paint. Acrylic roof paints, provided that they are formulated on "adhesion promoted" pure acrylic binders, can be applied directly to these roof sheets without a primer. The use of an anti-corrosive primer, when it is not in direct contact with metal, is a pointless exercise - and simply adds to the cost of the job.
If the coating on the roof sheets is chalking, wiping down with Mineral Turps prior to re-coating is essential. Sanding down of any rusted areas to a bright metal finish, and spot priming only these areas with an Etch Primer, completes the surface preparation procedure.
Before using an acrylic roof paint on pre-coated roof sheets, check with your supplier whether the binder is "adhesion promoted."

Coating of rat cages

This is one of the more unusual applications we have been asked to advise on. At the end of it all, it is all about the type of substrate to be coated, and the requirements of the dry paint film, just as in any other case. Rat cages are supplied with a thin powder coated layer, with limited resistance to rat urine. After a short period of time, the powder coating is broken down and the exposed metal begins to rust.
To re-coat it is necessary to sand the substrate down to bright metal where rusted, and to an even matt finish where the powder coated layer is still intact, before applying two coats of Chlorinated Rubber Enamel at 4 hr intervals.
Chlorinated Rubber Enamels are self priming on metal surfaces due to the very good adhesion to the substrate and very low moisture and oxygen permeability. They are resistant to both acids and alkalis, and non-toxic in the dry state. To ensure that the coating has dried sufficiently before the cage is re-used, it should be left for 24 hrs after application of the second coat.

Aluminium Roof Paints

Many roofs on rural buildings are still coated with Aluminium Roof Paints. This is a tradition that goes back many decades and is still very much alive. Problems occur when roofs are coated in both very cold and very hot weather. During winter months, day-time temperatures seldom rise above 15 degrees celcius with below zero overnight temperatures being the norm. This is compounded by dew-fall on most nights. It is best to only paint between the hours of 10 am and 3 pm at this time of year. Should the coating become wet - via rain or dew - before all the solvent has evaporated and the leafing of the aluminium flakes has taken place, an uneven or patchy appearance will result.
In summer months, day-time temperatures are often above 40 degrees celcius. Application of Aluminium Roof Paints in temperatures above 30 degrees celcius result in rapid sovent flash off giving the same uneven, patchy appearance as mentioned above. Early mornings or late afternoons, provided dew is not expected, are the best times to apply these coatings in summer months.