Form Release and How it Works

Ever wonder how form releases work and why they are better for concrete than regular oil?

All form releases are VOC compliant. Diesel fuel and motor oil or burnt oil work and are still used by some people but they are not VOC compliant. They also have the problem of staining concrete. Even though all form oils are VOC compliant, most still have a highly refined fuel oil in them.

There are different types of form releases but the one I will focus on is the dual reactive form release. Dual reactive form releases work by providing an oily slick film on the surface with fatty acids mixed into it to create a chemical reaction. I know I stated oil. Since the amount of fuel oil had to be reduced to make the form oils meet the VOC specifications they had to replace it with another type of oil. So they have added more natural oils. For the sake of this article, I will call them vegetable oils. There are many types that are used but vegetable oil is a term that is understood by all. The vegetable oils cost more per gallon than the fuel oils. So, the more expensive the form release, chances are the higher the concentration of a vegetable type oil. The oils create a slippery surface on the form which prevents the concrete from sticking.

The second part of the dual reactive form release is the chemical reaction, which is adding fatty acids to react with the calcium in the concrete. Concrete has a high Ph. When the fatty acids react with the calcium it creates something like a soapy film. The soapy film helps prevent the concrete from sticking to the form also.

When applying the dual reactive form release, more does not mean better. Pay attention to the coverage chart for the form oil that is used. Typically, the smoother or more dense the form, the less you will use per square foot. When you apply too much form release you will have too many fatty acids in that area which may create bugholes in the concrete. When you put way too much on the form you can or may prevent any reaction that could happen, which means prying the forms off by force and making a nice repair situation. When that happens feel free to call your local sales rep and they will be happy to sell you another product to fix the problem.

Solely water based form releases work with only a chemical reaction. There is water and fatty acids in the mix. Coverage is much thinner and you will never think you have put enough down so you will over apply, which creates the problems above. The water based ones work when properly applied with no rain in the forecast but must be reapplied after rain has washed it away. The other problem with the water based ones is that there is no back up activity to help break the forms away if the chemical reaction fails.