by wefalck » Fri Oct 16, 2020 2:30 am
Poor edge coverage means that the too much paint of a too high surface tension relative to the painted surface was used. The surface tension tries to pull together the paint, so that the 'blob' has an as low surface area as possible.
Glossy paints normally have a higher surface tension than matt paints due to high content of 'medium'.
Many plastic surfaces have slightly hydrophobic properties, which aggravates the problem, when using water-based acrylics.
There are several strategies to overcome the problem and some of them have already been mentioned, namely:
- roughing the surfaces by sanding it lightly and/or rubbing it with steel-wool
- careful degreasing (when using acrylics)
- spraying thin layers that dry up immediately - a thin film has less tendency to 'pull together'.
- first spraying on something matt (matt paint or primer - in fact on of the purposes of priming is to create a surface on which paint does not 'pull together').
Poor edge coverage means that the too much paint of a too high surface tension relative to the painted surface was used. The surface tension tries to pull together the paint, so that the 'blob' has an as low surface area as possible.
Glossy paints normally have a higher surface tension than matt paints due to high content of 'medium'.
Many plastic surfaces have slightly hydrophobic properties, which aggravates the problem, when using water-based acrylics.
There are several strategies to overcome the problem and some of them have already been mentioned, namely:
- roughing the surfaces by sanding it lightly and/or rubbing it with steel-wool
- careful degreasing (when using acrylics)
- spraying thin layers that dry up immediately - a thin film has less tendency to 'pull together'.
- first spraying on something matt (matt paint or primer - in fact on of the purposes of priming is to create a surface on which paint does not 'pull together').