Bubble-shaped irregular swellings.

BUBBLES
- Due to corrosion.
- Due to drying.
- Due to air trapping.

Due to corrosion:
1. Mechanical damage on the painted surface with subsequent humidity infiltration.
2. Insufficient preliminary substrate pre-treatment or incomplete anti-rust treatment.
3. Rust formation on sanded or damaged surfaces.
4. Insufficient panel sealing.

Due to drying:
1. High film thickness.
2. Too fast hardeners and/or thinners.
3. Too short flash-off.
4. Too high IR temperature.
5. Too short flash-off in wet-on-wet process.

Due to air trapping:
1. Insufficient putty or priming coat application.
2. Insufficient flash off time between primer and topcoat.
3. Air pockets in the priming coat due to unsuitable thinner.
4. Too high drying temperature

Sand until underlying layers by removing bubbles and/or rust. If necessary, apply an anticorrosive primer as soon as possible in order to avoid further corrosion phenomena.

- Repair the damaged points immediately and apply an anticorrosive primer in order to avoid corrosion.
- Apply the recommended paint layers, use hardeners and thinners as indicated on the technical data sheet, follow the drying times, in order to avoid drying bubbles.