When sealing flat, wood surfaces with epoxy (MirrorCoat, Clear Coat, Silvertip, or General Purpose), it is important to seal the entire piece in a single application to help prevent warping. A secondary function of the seal coat is to prevent air bubbles from forming in subsequent epoxy coats.
We have found the best way to apply the seal coat is with a 1/8 Nap Foam Roller. It applies the epoxy in a thin uniform manner. Apply the epoxy at 1/2 fluid ounces per square foot. Avoid thick applications as bubbles will form in the seal coat.
Seal the bottom first, then carefully flip the workpiece over onto a four-point support system. Small wood blocks with a padded surface positioned at the four outside corners work great. Next, seal the top, followed by the edges. Any excess epoxy can be wiped away to prevent drips. Allow the epoxy to cure overnight and then inspect the wood. The surfaces should have a uniform appearance. If the surface is blotchy, apply another thin seal coat.