S2 7.9 Daggerboard Delamination

[dljschuster]

Hello All. I'm new to this board and am looking for some advice. We sail an S2 7.9 out of the York River on the Chesapeake Bay. We keep our boat in the water most of the year, hauling every couple of years for bottom paint and annually for inspection and cleaning prior to the club racing season. We had a cold winter on the Chesapeake this year and when we hauled, we found a crack in the trailing edge of the daggerboard fiberglass that started about a foot from the bottom of the keel and extended about 18" above that parallel to the trailing edge. The glass has popped off the substructure on the port side up to about 1/4 of the way back from the board leading edge (determined by tapping on the board). It does not appear that the glass has separated from the subtsructure on the starboard side. We suspect water may have leaked in between the glass and the substructure and frozen during the winter, popping the glass from the substructure and cracking the trailing edge. We've been sailing it, as we or others we consulted didn't feel the problem was structural. We pulled the boat this week as the boat hadn't been sailed in over a month and the growth was bad enough to warrant a pressure washing. The cracking appeared to be slightly worse, but not highly degraded. We're strategizing how to deal with this in the off-season. Repair vs. replace. We have a line on another keel from a scrap boat, but we don't even know what kind of price would be fair. Any thoughts on that subject would be greatly appreciated. The repair option has been suggested to grind the glass shell back until we hit areas where the glass hasn't popped from the substructure, then build up the glass bonded back to the substructure. Its a large area and we're concerned about the amount of work that would entail and the durability of such a repair. The yard where we keep the boat thinks it would be cheaper to replace than repair. Given the shortage of parts like this, I'm reluctant to trash what we have even if we do replace it. Suggestions on repair alternatives?

[dave]

Welcome for my part!

The problem you're having isn't rare to the 7.9. Mine delaminated completely, the skins came off both sides!!!!! Also, go easy on the prying away the skin to see what's attached and what's not. It AIN'T a strong bond and you could wind up peeling the whole thing off after all, the whole shebang is built from polyester and it hasn't stood the test of time on this specific application!The repair method you describe is sound, just make sure that you get everything DRY and use epoxy when going back in, not polyester.

[Craig_in_DC]

I have a similar problem on the bottom of my keel. Last weekend a did a surface patch with West Marine epoxy. I'm going to check out the durability of the fix this weekend. The damage area I have is only on the very bottom, so my main concern is water getting inside and causing more damage. I trailer sail, so it is not a critical repair.

Craig in DC

[dave]

Sorry Craig, but the seam runs all the way around the board.............fixing one spot still leaves the rest to let water in between the glass skins and the filler core. For whatever reason, the two are NOT bonded together all that well.

[dljschuster]

Thanks for the advice thus far. Our disbonded area is pretty large, encompassing a pretty big area on the port side of the board. I'm hesitant to call it a delamination because that really isn't what is is. By all acounts the fibergalss sheath around the lead is fine except for the big crack at the trailing edge. I'm wondering if we can do a local repair on the crack and then drill a series of holes in the acreage that encpmpasses the disbonded area, injecting epoxy into the holes and trying to get it to fill the gap between the disbonded glass and the substrate. Any thoughts on the effectiveness of this? I'd rather not cut away large areas of what is probably perfectly good fiberglass just because it has disbonded from the substrate. Getting the inside dry and knowing it is dry is probably the trickiest part.

Dave
S2 7.9 "Three S2ges"
Williamsburg, VA

[dave]

Dave, something to ponder on things like this, and an old saying fits the bill: "There's never enough time (and/or money) to do it right but there's ALWAYS enough time (and more money) to do it over"!!!!

The one main spot where most folks REALLY screw the pooch when doing fiberglass repair is in the prep work. They don't want to or are afraid to do some aggressive grinding to get into fiberglass that's still structurally intact, meaning not riddled with white fractured laminate and still bonded well to all of the layers in the laminate and/or any substrate/core. Then there's the itching issue!!! There's no GOOD way around doing proper and correct fiberglass repair. Hole drilling and injecting epoxy works for some things some times, but I would be extremely leery of doing so in this application. Remember, the fiberglass skins are releasing from the board core, for what ever reason. I wouldn't trust anything else including epoxy to stick WELL to the board core until I had the core exposed, abraded and cleaned with MEK first. Even if the injected epoxy sticks reasonably well to the core, you will never get it into the bonded/unbonded transition area where the skin is starting to release. If there's still unbonded skin your problem will only be kicked down the path, and maybe not very far!