Now that the subwoofer box is assembled, it is time to fiberglass the subwoofer box for reinforcement. Start by laying the fleece over the face of the box, covering the ring you made in the last stage, leaving and excessive amount to cover the sides and the back of the subwoofer box for later. Staple fleece to the outer edge of the speaker ring. As you go along, spray adhesive to the face of the box, stretching the fleece and adhere it to the box. Make sure to staple the fleece around all the edges of the sides once the fleece is adhered.
Take your mixed fiberglass resin and paintbrush and apply fiberglass soakingly to the fleeced areas. once fiberglass is hardened and cured, remove the back, making sure to remove the 2x4 from it. Reinstall the back piece of the box and finish applying the fleece to the box, covering the sides and back. Staple to the back and remove excess fleece. Apply second layer of fiberglass resin over the box. Sand down fiberglass as smooth and flesh as possible.
