Form-release agents or form oils cost but a small fraction of the cost of the formwork itself, but they have a big influence on the quality and success of the concrete surface. Today, contractors can choose from among hundreds of form-release products, and new ones are still being developed. But with the myriad products available, it can be difficult to select the best one for a particular application. Fundamental questions to ask include:
- What form surfaces can it be used on?
- Will it provide clean, easy release without damage to either the concrete or the form?
- Will it produce a stain- and blemish-free concrete surface?
- Is it compatible with admixtures in the fresh concrete and with surface coatings that may be applied later to the hardened concrete?
- Is it ready for use without site mixing, and is it easy to apply at anticipated jobsite temperatures?
- Is it compliant with environmental regulations?
A table answers some of these questions by summarizing the characteristics and applications of more than 50 products.