Check the Weather Before Painting Your Boat

Check the Weather Before Painting Your Boat

Before you embark on the outdoor painting process, it's crucial to check the weather forecast. This article is crafted to guide you in making informed decisions as you commence the maintenance cycle of repainting your boat.


Six General Rules:

  1. Spring, early autumn and summer months are the only time of the year you should be considering preparing and painting your boat outside. 
  2. Relative humidity; we recommend you only paint when the relative humidity is >80%. If the relative humidity is above this point, it will effect the drying time, finish and performance of the coating.
  3. Dew point: The substrate you're painting should always be 3 degrees above the dew point. 
  4. Air and substrate temperature; it is advised to ensure that the air temperature is a minimum of 10 degrees Celsius, and the surface temperature is maintained above 5 degrees Celsius, please bare in mind that lower temperatures increase overcoat and drying time. 
  5. Steer clear of extreme air temperatures and adverse weather conditions, encompassing both excessively hot and cold days.
  6. Do not paint in direct sunlight, or when the substrate itself is excessively warm; you will find the solvent evaporated off the paint too quickly, this can result in poor flow, blistering, rapid drying, cracking and loss of gloss. 

What is Humidity? 

Relative humidity (RH) is a measure of how much moisture the air holds compared to the maximum it could hold at a given temperature. It's expressed as a percentage. High RH means more moisture in the air, while low RH indicates drier conditions.

What is the Dew Point? 

Dew point is the temperature at which air becomes saturated with moisture, leading to dew formation (condensation). It's the point at which air is cooled to the temperature at which it can no longer hold all its water vapor, resulting in condensation.

Finally, here are five steps to remember when applying marine paints:

1. Apply your coating in the middle of the day, avoid late afternoons, evenings and early mornings when condensation is likely. 

2. Choose a dry, well ventilated, dust free area.

3. Gently sand and clean between paint coats to prevent contamination that may affect adhesion. Additionally, ensure that the surface being painted is thoroughly dry, any moisture that gets trapped with result in micro blistering. 

4. Keep good airflow, don't be tempted to cover the area you have just painted with tarpaulin, this can cause excessive moisture, and solvent entrapment. 

5. If in doubt contact our friendly experts on 01482 320194 or via our online chat, we are available Monday to Thursday 8:30am until 5pm or Friday 8:30am until Friday 3:45pm.


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