Step 1: Remove the damaged area. Before you can start reconstruction, you have to remove the damaged sponson. For this type of repair, you can use almost any style of saw to cut away o the damage.

Step 2: Make replacement piece. In an accident, one sponson usually escapes unscathed, and you can use it as a template to make the replacement pieces. the most important part is the inside vertical section, which establishes the depth and length of the area being rebuilt. Make this vertical section out of 1/16- or 1/8-inch plywood. When you’ve made the part, double-check its shape against the intact sponson to ensure accuracy.

Step 3: Prepare the main hull and sponson. The hull I repaired for this article is wood over foam, so the main sponson was made exclusively of foam. You can choose another materials.

Step 4: Join the parts. When the epoxy has cured and the dowel is secure, attach the sponson to the hull. I highly recommend a slow-curing (at least 30-minute) epoxy. Slip the dowel into the mating hole in the hull and press the hull and sponson tightly together. Carefully align the sponson with the hull, and wipe off any excess epoxy; use masking tape to hold the parts together while the glue is drying. This is a critical step in the rebuilding process

Step 5. Painting. Keeping your construction is dry. Paint it slowly, slowly. I recommend a half of day. Don’t touch until it’s quite dry.

Good luck!