Additive F is a miracle breakthrough in the production of epoxy surfboards. It does so many things it’s unbelievable. In laminating, it helps wet the cloth eliminating most air bubbles (especially around wings and boxes), reduces the amount of resin needed, and most of all eliminates blush. Blush is what causes the banana peel effect. In hot coats it eliminates blush, fish eyes, other surface blemishes, and increases Barcol hardness. This increase in Barcol makes the board sand easy and improves the bond and strength between layers. It also doesn’t interfere with recoating as wax solution in polyester does. That means no sanding between layers. 4oz bottle.