Painting can be quite technical and there are many things that can go wrong. In this blog, we will cover a few of potential issues that can affect your paint job. Utilising a professional painting company like Painting Pros can prevent painting problems.
Efflorescence
Efflorescence (means to “to flower out” in French) is a technical painting term referring to the white mineral deposit found on concrete or masonry surfaces, particularly brick. It occurs when salts migrate to the surface of a porous material and forms a coating
Efflorescence (which means “to flower out” in French) is the migration of a salt to the surface of a porous material, where it forms a coating
Trained, experienced painters such as Painting Pros recognise situations where efflorescence may occur and can use a number of techniques to reduce the possibility. For example treating the surface to ensure it is clean, dry and does not have any traces of mould or algae. In addition, alkali-resistant sealer and specific topcoats can be used.
Typically, efflorescence occurs during initial construction. Therefore, curing the surface (waiting for approximately 30 days prior to painting (or 10 weeks in the case of fibrous or set plaster)
Surfactant leaching
Surfactant leaching is when blotchy, oily, or sometimes glossy, marks appear on painted surfaces, usually within the first few weeks of painting. The marks can vary in colour from clear, white, orange, tan or brownish in colour.
This phenomenon can occur with either external or interior painting and occurs when drying conditions are sub-optimal
Utilising experienced, trained painters, such as Painting Pros, can ensure issues like these do not occur.
Drying and Hardening of Water-Based Paints
Water-based paints go a two-phased drying process:
Phase 1: Evaporation
Phase 2: Coalescence
The final hardening of the paint is dependent on the final coalescence leaving the paint film which can take up to two weeks under optimal conditions (temperature of 20-25 degrees and humidity less than 50%). Longer under sub-optimal conditions. Precautions should be taken prior to complete drying, such as avoiding moisture, humidity, rain, cleaning of surfaces and resting objects on freshly painted surfaces.
Therefore despite the paint surface looking and feeling dry, the paint may not have hardened. Therefore experts such as Painting Pros can advise the best way to treat your newly painted surfaces.
Chalking – as defined in AS/NZS 2310:2002 – Glossary of paint and painting terms, is “The appearance of a loosely adherent fine powder on the surface of a paint film, arising from the degradation of one or more of its constituents”.
Chalking is due to the paint coating breaking down due to UV light. Some chalking is inevitable. However, the use of specific paints and techniques can reduce the time taken and the amount of chalking.
Painting Pros use specific products such as The Dulux® Weathershield® which guarantees premature blistering, flaking and peeling of the coating system.
Stay tuned for part two when we will investigate some more potential painting problems.