If you notice any bumps or damage after sanding the hull or deck, use one of SVB's many fillers. Fillers are used to compensate for unevenness that is left behind after grinding; but they can also be used for filling inholes (for example, osmotic blisters). The various fillers differ in their characteristics, such as their level of water resistance, curing time and grindability. In general, you should only use epoxyresinfillers for underwater jobs and on larger surfaces.