Failing to properly seal a project can result in excess bubbles in the final coat. More times than not, a seal coat is necessary. A thin seal coat helps to fill in and seal up porous areas of the project. A seal coat is especially necessary when pouring epoxy over wood, encapsulation projects, and other porous substrates. Although thin, this is additional epoxy that needs to be accounted for when calculating total epoxy necessary for a given project.