I'm Experiencing Pinholing When Spraying Tikkurila Paints
Pinholes tend to appear when too low a film build is applied to the substrate. If the spray film is too low due to lack of pressure, wrong tip selection or over thinning then the atomised product does not flow correctly over the substrate and gaps appear (pinholes). Pinholes are most common when applying black and white as visually it is very difficult to distinguish between a first coat and a second. When using these colours the natural propensity is to apply a lower film build by sweeping over the surface faster in order to avoid runs and sags. Pinholes very rarely occur when first coating over primer as the shade differentiation is such that the sprayer can easily see the volume of paint being applied and is more confident that the film is as it should be.
Issue: Pinholes in sprayed film
Cause: Low film build
Solution: Apply more product.
This can be achieved as follows:
- Adjust pressure
- Change tip size
- Slow down sweep over substrate