On the reliability of the yields reported on the packages.
This is a subject that can undoubtedly generate more controversy, and without wishing to go too deeply into this matter, it is worthwhile to take some factors into account:
- The yields are calculated using a mathematical formula that does not take into account factors such as the state of the surface to be painted, something that can significantly influence the performance. However, in Pinturas Jafep we always report the performance of our products providing a range between two values where the higher is the result of this mathematical formula, and the lower is the estimate made by our technical department taking into account the most common characteristics that we can find in the surfaces to be painted. It is important to emphasize that some manufacturers ONLY report the performance resulting from the mathematical formula and that it rarely agrees with reality.
- Nobody gives away pennies for pennies (or euros for pennies): It is evident that when we find a paint that offers a similar theoretical performance to another paint for a price that can sometimes be up to 5 times cheaper, something does not agree. It should be noted that when calculating the performance, values such as the thickness of the layer or the evaporation of the paint are taken into account. These values are applied at the free will of the manufacturer and are often manipulated to obtain more generous performance values that rarely reflect reality.
Is there a standard for performance calculation by manufacturers ?
Today a , the most widely accepted formula for calculating yield is as follows :
Theoretical Yield (m²/l) = CVS (%) * 10 / Dry Thickness (microns)
Where CVS is the solid compounds by volume that an undiluted paint can have, or what is the same, what remains once the undiluted paint is completely dry. P.E. 65 %.
The dry thickness in microns is the coverage we want to achieve, the “layers” or “coats” of paint.
Unfortunately, there is no standardized way to calculate these values, so we can only rely on the good faith of the manufacturers when making these calculations.
In the technical department of Pinturas Jafep our staff calculates the performance using the values as realistically as possible and taking into account that the surfaces to be painted are not always in the most suitable conditions to achieve the best performance.
