Repairing an EPS board

I backed my 4,500 pound boat into my Shred Stixx Jamako! This board is NOT the Poly U core and Polyester resin model. Using a polyester resin based repair can cause further damage. In this repair I'm going to show my procedure for working with epoxy and glass.

The project:

It's a little hard to see, but I actually broke the stringer. The deck of the board remained intact, but the bottom was severly cracked exposing the blank and as I indicated above the stringer was broken.

If this were a more minor repair without any delamination or structural damage some epoxy with microballoons would, no doubt, have been sufficient. I wanted to add some structural integrity to ensure I didn't snap the nose off in use.

I opted to epoxy a e-glass fiberglass patch over the offending area.

The first step is to prepare the area. Much like body work, I carefully pulled the dented out as close as possible to it's original shape. Including twisting the nose back into alignment. Then I sanded the entire area to give the epoxy and patch a good grip. Finally wiping the surface down with a tack rag to remove any dust. It's not a good picture, but the prepped board.

The supplies for the epoxy. My favorite for mixing is a paper plate Toss it when done. I also mix with a tongue depressor. I also split one depressor in to a tool I could use to force epoxy into the gap in the stringer and under the sections of the break that had delaminated from the core.

I had a scrap of e-glass left over from a project, but it is easy to acquire at places like Tap Plastics. This piece was 3.7 oz and will be adequate for a patch. I prefer to leave the existing board intact and merely overlay, rather than cutting back the damaged glass. Personally I am all thumbs, so I do more damage when trying to cut back and fill in

When working with fiberglass...gloves will save you from itching later and sharp pinking sheers will leave a smooth edge for laminating.

I cut a patch big enough to cover the entire area, including wrapping around the rails.

It seems I didn't get a picture, but I mixed the 1 hour epoxy and then worked carefully under the cracked existing fiberglass, as well as down into the split in the stringer. To ensure that I wouldn't have any water seeping into the crack, I ran a bead of epoxy along the cracks before laying down my patch. I spread a very thin layer of epoxy down on the surface.

Here I have laid down the patch and started wetting it and working the epoxy into the glass and removing excess.

All laminated and curing. After the epoxy is fully cured I'll sand it smooth and then polish it as best I can.