• Why do bubbles appear in the varnish during application?

    Bubbles in a product such as varnish, lacquer, paint, etc. can be caused by :

    – mixing too quickly. Air enters the product at this point. This air comes out after application as long as the product is not dry. The air may even be trapped before it reaches the surface.

    – mixing a product that is too cold. If, for example, a 5kg pot of varnish is cold, the viscosity is different and it will be more difficult for the bubbles to rise to the surface. This can also happen even if the mixing is done slowly. There will always be bubbles.

    When applying a varnish at the right temperature to a substrate that is too cold, the same phenomenon will occur. The viscosity of a liquid increases as the temperature drops. So the lower the temperature, the thicker the product.
    Bubbles can be trapped in the varnish if it is not fresh enough. (if the potlife is exceeded).

    Note: a 5 kg package of varnish needs several hours to reach the temperature of the room and of the to-be-applied surface.
    The same rule applies to the temperature of the substrate.
    Sometimes, at the end of a job, we go and fetch the pot of varnish that was left in the van outside (colder temperature) and think that in a few minutes or an hour the liquid mass of varnish will reach the right temperature. This is not the case!

    An ideal temperature for varnishes to be applied properly is between 12 and 25°C for most clear varnishes and sometimes between 10 and 30°C.
    It also depends on the ambient humidity.
    The higher the temperature, the greater the fluidity.

    These rules are supposed to be known by professionals in the sector.


Beal International installs cookies to analyse the use of its website, to improve your browsing experience and to better tailor the content and the advertisements on its website to your interests. Partners with whom Beal International collaborates can also install advertising cookies via the Beal International website in order to show you advertisements that may be relevant to you on other websites and social media. Click on "I accept all cookies" to accept the cookies and go directly to the website or click on “Change settings” to change your cookie preferences. Please note that if you block certain cookies, this may hinder the correct functioning of the website.

Change settings I accept all cookies
Edit Cookies.
  • Some cookies are essential for the functioning of the site and are automatically active (eg session ID) You can’t disable these cookies. Beal International’ first party analytical cookies make it possible to analyse traffic on Beal International website. These cookies are purely statistical. They enable Beal International to analyse the use of its website by, for example, quantifying visits to the site, determining whether there are perfomance issues or bottlenecks, etc. This information helps us to provide the best service and performance.

  • We use Google Analytics to study the browsing behaviour of visitors to this site. This is a website analytics service provided by Google Inc. Google Analytics collects information on an anonymous basis, such as the number of visitors to this site, their country, region and city of origin, the type of browser and operating system they are using, the date, time and duration of visits, the pages consulted, and what other websites they visited prior to coming to this site. Our use of Google Analytics includes the Demographics and Interest Reporting component.

  • These cookies may be set through this site by our advertising partners. They may be used by those companies to build a profile of your interests and show you relevant adverts on other sites. They do not store directly personal information, but are based on uniquely identifying your browser and internet device. If you do not allow these cookies, you will experience less targeted advertising.