Epic day Saturday! 4 or 5 hours of drivin' the Stealth hard in 20 knots, two foot chop over a developing swell on Flathead Lake. I got this boat from Gary F early this spring, and I've been sailing it most every weekend for the last four months, and this was the first time I felt truly hooked up with it solo in big water. Can't seem to bury that lee bow! Hard to know whether it's the foiled rudders or the tall bows, but I sure like it!
Well, on a downwind run under spin, I hear this loud(and sickening)CRACK! I throttle back to investigate, and thirty seconds later another one just like it. I finally looked over the outside of the windward hull to see the daggerboard at a peculiar angle. Thought maybe the board snapped, and was concerned about saving the remains. But about then I noticed how low in the water the hull had become, so the focus quickly shifted to the shortest distance to shore. Which fortunately wasn't too far. Lucky, since I'd been as much as 3 or 4 miles offshore at times over the course of the afternoon. Hull was pretty full by the time I got to land.
Turns out the dagger tore aft thru the bottom of the boat, busting the daggerboard well too. So, gotta put it back together, hopefully with some input from you guys!
I'll post pics soon. The first question is where and how big of a hole to cut to allow me access to the daggerbd well. My thought is to carefully remove a 10" x 10" section of the inner wall of the hull, and flange it on the inside when the repair is done. Is that too big a hole? Can I make it bigger? Is this the least stressed section of hull to open up? Other spots to consider?
The daggerbd well actually broke quite cleanly, about midway down, and separated from the bottom of the hull cleanly as well. The upper section is intact and still attached to the deck. And all of the bottom of the hull, including the daggerbd exit profile is there still. So if I can get sufficient access, I think I can push/place all the bits back into place and sufficiently reinforce it all to ride another day.
So, thoughts on weights and types of cloth? I'm comfortable with West System products, and I have a vacuum pump if needed. Flight Risk has given me a fair amount of practice with these materials! I'm willing to spend $s on carbon if it's appropriate, but is S glass sufficient in this application? What weight cloth?
Anybody know the allen wrench size(mm?) of the bolts securing the beams to the hulls? I wanna buy the highest quality wrench I can find, 'cause this boat(2002) has seen a lot of salt water before coming to me, and I don't expect them to break free without a struggle. It doesn't appear that there's much chance of getting penetrant onto the threads. Any tips here?
I plan to run this by John Pierce(the builder), but all advice and encouragement is welcome. These's lots of season left and I'd like to float her again soon. Help me out boys! Thanks!

Dave

Yes you are on the right track make a window to see inside then glue it back in place with a layer of glass over it. Pound around to make sure you don't cut into bulkheads. Make the cut on the inside face of the hull not as bad to fix if you aren't good at faring and blending or want to rush. Use west system or other epoxies and don't use auto body filler it will pop with time. Ask the builder for their advise. You may have to make several windows and make them big enought to work through.

Get hold of John P at Stealth for advice. THere may be a better way as the boat is clamshell construction.

http://www.stealthmarine.co.uk/

I would phone first (yes a little expensive) and then follow up via email.

Might save a lot of hassle!

You could use voipbuster or a comparable service to get free calls. Getting up early is the worst part! Works great for me! I am not associated with them, I just use them to call around the globe for free. (I own a hardware internet phone, but in a pinch I have used my laptop as a phone too.

The manufacturer should always be your 1st point of call.

Skype. 2.4¢ / minute to the UK, incl VAT. Get a headset/microphone for your laptop and Bob's yer uncle.

Dave,

Go ahead and cut her open, thats the hardest part. Once she's opened up you should be able to figure out how to fix it pretty easily. Making her watertight is pretty easy and straight forward, making her look like she hasnt had major surgery is harder. I would fix it and sail her now, and worry about pretty this winter.

When you close the hulls back up, that repair should mirror the original construction as closely as possible, so if the boat was made with S glass and vinylester, use that in the repair of the hull when you close it back up. Epoxy will stick to vinyl, but not the other way around, so its better in the long run to stick with what the builder used. Vinyl is more toxic so follow the directions and dont breathe it or smoke around it. Most boats these days are made with Vinyl, its cheaper than epoxy. You also dont want to create a hard spot in the hulls, or a spot that doesnt flex the same way the rest of the boat does, so use the same material as the rest of the hulls if you can.

If you add carbon to the daggerboard wells, I would add it to the whole part. Again, you dont want to create a hard spot, or a spot that doesnt flex like the rest of the part. So adding carbon just at the break might transfer the load to the spot on the daggerboard well with no carbon on it.

I'm curious why the daggerboard well broke in the middle, was the top of the board half way down the trunk? Or do you think you flexed the hulls top to bottom?

Bill

Talk to John P first.

Yeah Mike, that's what I had in mind for cutting the window. And I can see inside pretty well from below, so I know where the bulkheads are.
Bill, I will talk to John about vinylester vs epoxy for the repair. And I understand about wanting to avoid creating hard spots. I'm still curious about how the failure occurred, I didn't feel an impact, although there is some debris on the lake. There was no visible damage to the daggerbd itself, but it's pretty stout. It seems like the daggerbd may have dropped deep into the well, but I'm not sure how that would have happened. But as is visible in the 3rd pic, the upper half of the daggerbd well is still intact. Hit a big fish?
Thanks for the great response guys. Thoughts on cloth weights and number of layers? I'll keep you all posted as the repair progresses.
A few more shots:
1st one shows the remaining intact upper section of the dggrbd well,
viewed from below.
3rd one shows the lower section of the dggrbd well, it's just loose inside the hull now.

Dave

Either 1 or more of the following happened:
1. The board slide down to far in the trunk (best case and most likely)
2. You ran over something (doesnt look like that happened)
3. The trunk/hull failed under the stress of sailing on a windy day (worst case)

It looks like the board slid down to far and the loads on the daggerboard increased and the trunk didnt have enough structure to hold the top of the board in the middle of the trunk, and it sheared off the trunk and then the second crack was the bottom part of the trunk tearing away from the hull.

Or you ran over something, which pulled the board aft, and the trunk sheared in the middle and then delaminated off the hull. I doubt this happened because the top of the trunk would most likely be damaged as well, and the board would be banged up too. Most of the time when you run over something the board takes most of the abuse, followed by the trailing edge of the trunk/hull. The impact usually james the trailing edge of the board backwards into the hull like a knife. It doesnt look like that happened.

I'm betting the board slide down to far, you didnt notice it and the loads from the board being to deep sheared off the bottom of the trunk.


If thats the case its good news, just glue it all back together and make sure the board cant fall below the deck in the trunk.

If the board didnt slide down into the trunk, and you didnt run over something, I would be really worried. If thats the case it means the trunk failed under normal sailing conditions. Thats a pretty serious design/build issue.

How did it happen? Too much pressure on the board?
Do you have a pic of the board as well?
Good luck with the repairs.

Looks to me like its time for a new hull.

Good luck with that.

Just a couple of lessons I've learned over the years ...

1) It's easier to work through a bigger hole then a too small hole

2) It's just as easy to repair a larger hole then a smaller hole cut for access.

3) Cut a access hole like you do when carving a "pumpkin" .... at a angle. I set my Bosch jig saw to a angle of 15degrees.

4) I mask off the area to be cut out w/ masking tape and draw lay-out lines to follow while cutting. This prevents chips and sloppy wiggly cuts. Use a new sharp blade!!!!

5) I drill two holes at opposite corners diagnally from each other just big enough for the jig saw's blade to fit into ...

6) Check w/ the builder BEFORE cutting and obtain any advise you can ...


From the pics' I think you will need two access holes ... one forward of the trunk and one aft as you need to be able to work on both sides of the trunk .....

Harry

Yeah Bill, I'm also thinking the most likely scenario is that the top of the board somehow dropped below the deck level. The daggerbd well is very lightly constructed, just designed to keep water out of the hulls., I imagine. The deck and bottom of the hull were certainly designed to carry the loads. The board did slice aft maybe 5 or 6 inches, but I'm inclined to think that was collateral damage. When I first saw the board it was canted outboard, as would be expected for the windward hull if the board did indeed drop too far. I'll have to look closely at the boards, but I think the only thing preventing them from decending below deck level is the rope handles. Some sort of positive stop is certainly to be developed.
Thanks to all for the input. I've emailed John P, and I'll try the various Inet phone options suggested. Keep it coming, I won't start til I've heard from Stealth.

Dave

Vonage gets free calls to the UK.

I'm no expert on this but my Fox looked very similar when the hull blew up on it. On the Fox I was able to remove the top cap and get inside for the repair. I purchased a new topcap and dagger well and replaced them. My dagger had broken in the hull and sheared up at the break point. It would appear that the diagnosis of the board slipping into the well is the most likely cause of this damage if the board didn't snap. Does the Stealth have a topcap that could be removed instead of cutting a hole in the hull?

Thats absolutely fix-able.

Dave,
How about making a collar for the daggerboard trunk. Can you get the bottom half out of the hull? If you can get the bottom half out, make a sleeve and then slide it back up onto the top half. Then glue the bottom part of the trunk back down to the hull.

The only tricky part is going to be getting some reinforcement on the inside of the bottom of the hull.

Think about using wire to pull everthing back into shape once its glued. And creating some internal backing structure that you can sandwich some glass in between the broken parts and the solid parts on the inside.

I'm trying to figure out if you could pull it all back together without cutting lots of big holes in the boat.

Bill

I always like to think I hit something....even if I did not. From the repairs I've done a few holes big enough to put two hands in work well or space the holes one for each hand.

Big job repair work is harder then building a new boat just less work.

I agree with Bill here. From the pictures, it looks like the board slid way down in the trunk. These trunks typically have very thin walls. Once it was down there, the board probably punched through the trunk and that was the first crack you heard. At that point, the board was probably not aligned well with the direction of travel and fighting the rest of the boat/rudders/boards with a ton of lift which caused the failure of the exterior/bottom of the hull - i.e., the second crack you heard.

5oz glass would be a good medium weight to work with. Epoxy is easy and very strong and bonds well with cured plastics. Vinylester resins approach the mechanical properties of epoxy but don't bond quite as well to cured plastics. polyester is very low cost, doesn't bond well, and has the least strong properties. If you intend to finish with gelcoat, use vinylester. you can gelcoat over epoxy but it's tricky to get a decent bond.

I'm not sure if you should cut the hole in the deck of the side...though I'm thinking the side may be the way to go. Mike showed a good trick to replace the 'window; you cut out by glueing plates of fiberglass to the inside of the hull - and that should work well. I have also use a similar technique by bonding popsickle sticks to the inside of the hull and clamping until they cure. Then glue the window back in place. Then using a dremel, I grind through the entire perimeter of the seam to the inside glass. I glass in a few layers of 5oz on the inside layer, then I fill with Ultimate Bondo (yes, bondo - I've had it work very well...just ask Tad...but use the ultimate version), sand a nice taper on the outside glass layer, and put a layer of glass again on the oustide...fair to finish with ultimate bondo, and gelcoat to finish.

With mike's fiberglass plates, if you get them all the way around the hole, you may be able to save the step of grinding to the interior layer of glass.

I did a similar thing last summer with my new Blade. I hit a submerged rock with my daggerboard. It barely slowed me down even though I was on a broad reach in only 10 knots of breeze.It twisted in the trunk and caused the hull to fill with water. A good friend helped me repair the dammage. We ground off the deck plate to make it easier to get inside for the repair. There are a lot of guys on this forum with a lot more experience with fiberglass than me. My only suggestion is that you make sure you glass in the new daggerboard trunk correctly. A small error may make a big difference in the orientation of a high aspect daggerboard.