Spray Deflector

By Jan Mundy

One practical application of StarBoard is spray deflectors. These produce a dramatic difference on "wet" runabouts and cruisers, deflecting the spray downwards, and off the deck. Essentially that's the purpose of a chine, but often it's too narrow and requires an add-on piece.

Strong and durable deflectors made of StarBoard won't require any maintenance or painting, and blend in nicely with the hull. They are mounted on or just above the chine of a hard-chined boat, or on a boat that doesn't have a chine placed at a height that deflects the spray. Length is normally one-third of the boat, measured at the chine. For example: 6' (1.8m) deflectors were installed on the 20' (6m) Raymond Hunt-designed '60s-something runabout shown above. These were milled from white, 1-1/4" (3cm) thick StarBoard, cut wide enough so they don't look out of place but not too narrow or they'll be ineffective.

Spray deflector made of King StarBoard mounted at the chine prevents water from spraying upwards onto the deck.

Make a pattern for each side of the hull; it's likely the hull contours are different. StarBoard is best cut with a table saw or radial saw operating at 1,275 rpm and using a carbide blade that has 50 to 70 teeth. Router the outside edges with a 1/2-round carbide bit. Lay deflectors in position and check the fit. Drill holes for 1/4" (6mm) screws from the inside hull if you have access; otherwise, predrill the StarBoard, drilling slightly oversized holes (in the StarBoard only) to allow for contraction and expansion and counterbore the heads for a StarBoard plug. Prep the mating surfaces, removing any wax from the hull with acetone.

You'll need to seal the fastener holes in the fiberglass. Some professional builders bed screws in 3M Marine 5200 polyurethane sealant, but its ability to adhere to StarBoard is uncertain. But it will stick to fiberglass and StarBoard doesn't absorb water, so use either a polyurethane or polysulfide sealant. We don't recommend gluing on deflectors with StarBond, in case you need to replace or reposition them.