How to Make a Plug Mold to Make a Fiberglass Piece
- 1). Design and sketch the shape of the plug. It should be the same size and shape as the original you are trying to reproduce. Determine how you will need to alter the foam block to recreate the shape.
- 2). Carve the foam into the shape. Cut off large chunks of the foam with a hand saw or large knife. Shape the block with smaller knives, picks or screwdrivers. Work slowly. You can always remove more foam, but adding foam back is difficult.
- 3). Spray a coat of acrylic sealant onto the foam. This prevents the resin from being absorbed by the foam. Allow it to dry until it is no longer tacky.
- 4). Mist the plug with a thin coat of mold-release spray. Allow it to dry. Apply four more coats in the same manner. Allow it to dry to the touch before applying the fiberglass to the plug.
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