King StarBoard Plastics can be bent to form a large radius or a very tight radius.
How to Form a Large Radius
Bending StarBoard around a large radius takes a heat gun, and a lot of time and patience.
Begin by using a heat gun to apply heat evenly to the piece of StarBoard you want to bend. Don't hover too long in one place, and take care to keep the heat gun 8-12" away from the surface. If you get too close, the heat will scorch the surface. While heating the StarBoard, bend it slowly to shape it around a large radius. Because the StarBoard has a tendency to relax back to its original position, you may need to over-bend it slightly. Continue heating and bending until you form the desired radius. Clamp the piece in place until it cools. To avoid damaging the surface, use shims under the clamps.
(Photo: King Plastic Corporation)
How to Form a Tight Radius
To form a tight radius, you'll need to use a bending bar.
Start by cutting a 90° groove in the StarBoard at the desired bend location. Cut the groove to a depth that leaves .05" - .10" of material (less material means a tighter radius).
(Photo: King Plastic Corporation)
Next, use a heat gun to heat the bending bar to 300-350°F. Place the heated StarBoard on the bending bar and apply weight (10-15 lbs./ft. of StarBoard being bent) evenly across the surface. The weight is used to ensure the entire StarBoard surface is touching the bending bar. The amount of weight depends on the heat of the bending bar. Because StarBoard has a tendency to relax back to its original position, you may need to over-bend it slightly.
(Photo: King Plastic Corporation)
Leave your part on the bending bar for 1 to 3 minutes; remove the piece from the bending bar (it's common to see residue on the bar). To ensure that the radius holds, clamp the piece of StarBoard in place until it cools.