Painting and recoring

[darkstar32170]

I've been promising to get photos of the work I've done on "Dark Star" posted for months. I've finally started. Its still a work in progress but anybody who wants to see the start can go to: http://web.me.com/dlstudios/Site/Dark_S ... _2009.html

Also I hear that at least one E32-2 was out racing this past weekend. Sounds like they're lucky the rig is still standing thought. At least they were going upwind when the backstay let go.

[Motorboat!!]

Looks like a lot of work!
Yeah, I think we are lucky to still have the rig. It was blowing about 20 on saturday when we eased out to round the windward mark, then I heard an explosion. At first I thought it was my boom, which is probably the next thing to break. Instead I looked up and saw the backstay missing and the mast wobbling back and fourth. As it turns out, the previous owners needed to bridge a 3" gap between the backstay and the mast crane, so they installed a shackle to the crane and hooked the backstay to it. The shackle ended up failing (britle fracture, I have never seen that happen before). So anyway, I am fixing it the right way this week, getting a proper length backstay and fitting.
Too bad the backstay had to break when we were in second place for the race.

[rocklobster]

Nice work. Thank you for the helpful images. One question... when "re-coring" do you cut away the entire deck, or just peel off the top layer and balsa core leaving the bottom layer. I have cracking around the lifeline stantions that I would like to repair.

Thanks,
Doug

[admin]

Wow, nice work, David. I always thought Dark Star was one of the best looking E 32-2s...now I know it is. Any chance you guys are doing Block Island this year?

[Pterobyte]

Nice work. Thank you for the helpful images. One question... when "re-coring" do you cut away the entire deck, or just peel off the top layer and balsa core leaving the bottom layer. I have cracking around the lifeline stantions that I would like to repair.

Thanks,
Doug

The deck transition from cored to non cored at the rail. The C&C make and abrupt transition. This means that the stanchions are usually on just glass. The is topic needs a thread all its own. Usually you don't have to re core these. If the stanchion base is over the core and causes leaks then you have to re core it.

We are putting some reinforcing knees in under each stanchion. I'll create a thread on the Stanchions and post what we are doing.

[rocklobster]

The cracks around my stanchions extend to the cored deck. Any help would be MUCH appreciated.

Thanks,

Doug

[Pterobyte]

I drilled 1" holes with a hole saw through the top but stopped before going through the bottom layer. I did this on about 2" centers until I came up with dry wood. It usually took 2 -3 holes. Then using an allen wrench in a drill bit i dug out all the wet material. Then I filled the hole san substrate with West System and 406 filler, then fared with 410 filler. This will add some weight but also a lot of strength.

If you have to create too many holes, turning the deck in to swiss cheese, cut back the top layer in a reasonable shape and fill the deck with a foam core and then layer glass, I would use several layers of 10.5# bidirectional mat, to replace the top layer.

Use epoxy resin on all your polyester. Epoxy has much more mechanical strength bonding then polyester and fore repairs all you have is mechanical bond to the original material.

I was lucky in that I never had to drill more then 4 1" holes. I also explored the deck using a 3/16 drill bit looking for wet areas.

[darkstar32170]

Some answers to questions asked above:

We probably won't do Block Island Race Week. I know that seems ridiculous since Block Island is only a 4 hour sail from my home port. If I had a crew good put together by mid May it might be a possibility Anybody interested?

To RockLobster: When re-coring the deck I cut through just the top layer of glass and then pried that off and removed the core. Even core that looks good can contain a lot of moisture. If you insert a chisel or flat head screw driver into the balsa and start to pry the balsa up you will notice liquid appear on the surface of the balsa. I would enlarge my area by about an inch at a time until I found dry core. I was surprised that moisture doesn't necessarily travel very far in end grain balsa, but if it does travel it does more downhill rather than uphill.

Pterobyte is correct that the core does not extend all the way to the edge of the deck, and the stanchions should be mounted in the area of the deck that has no core. From the underside of the deck you should be able to see where the core ends. The cutouts I made around my chainplates extend to the edge of my core (see photos - last page of most recent current website - I'll be adding more soon). The cracking you see around you stanchion bases my not extend deep enough to allow moisture to get to the core. Most cracking that you see is just in the gelcoat. Because the deck is so thin at the perimeter it flexes quite a bit if you push hard against the top of a stanchion.

I have cast some large glass and epoxy "washers" that I was going to trim and then install under the deck to spread the load of the stanchion. I cast them in polyethylene coffee can lids. I've seen the knees the Pterobyte is installing and they should work too but I think my "washers" will be easier to install (and remove if they don't work) and should be nearly as effective. Like Pterobyte suggested cutting a couple 1 inch holes is enough to check for moisture. I'd do this check at the area with the most cracks first. If you find no moisture then you can skip the rest. I know it sound silly but if I didn't see any moisture my final moisture test was to put the bottom surface of the balsa to my lips. You can actually feel the moisture this way even if you feel it in you hands.

I have seen photos of deck re-coring jobs where the top skin is removed in one piece as that it can be replaced and the repair is completed by glassing over the perimeter (after beveling both edges), but you can't really be sure that you've gotten past the extent of the moisture.

I'll have some more photos posted on the site over the weekend.

[rocklobster]

Thank you David (Dark Star) and Pterobyte. I'll check out the pictures and see if I can muster the guts to cut into my otherwise perfect deck!

Doug

[peter ross]

David, I still can't get over all the work you did with the rig standing, great job.

There are a couple of things to look for regarding the bad core. The most dangerous is the loss of the inner skins at the bevel. Wet core around the stantion bases really weakens the laminates inside and out. The worst damage seems to be where the bulk of the crew sits when on the rail. Getting off the rail, the stantions are torqued hard. In the case of my (late) 25 deck, I was able to pull the midship stantions all the way to the cabin, with little effort. The inside skins were fine though, but the rotted core had weakened the laminate so much it was totally flexible. On Ursa Minor it was different, the inner skin had broken at the bevel. This means the inner skin is no longer doing it's job, the problems too many to list.

On GFornal's boat, I chose to tape the hull and deck, waxed the surface and layed up knees in place. When cured they were removed and cleaned up a bit before stantion installation. This method allowed the knees to be removed for any reason, including rebedding he flange. Made certain the knees were large enough to act as backing plates for the stantions. Ursa Minor need the added strength of the knees bonded to the hull, so I glassed them in place. That was much easier but the option to rebed the flange is challenged a bit.

Really inspect that bevel fore and aft, look for the tell tale black mold. A simple fix and not a bad idea at all if you can, glass a tape or two over that bevel, it can only help. I would also suggest using vinylester resin, not epoxy for that fix, I kinda think thermal expansion is more important in that area than the use of epoxy, plus the vinylester can be gelcoated easier. The epoxy/carbon traveller beam on GF's 25 was gelcoated, but the process is a pain, wipe with water is all it takes for midcoat adhesion. ( I do NOT suggest anyone do this)

[darkstar32170]

Peter: I don't seem to have any real deck problems at my stanchion bases and the bottom layer of glass at the bevel seems to be undamaged. But now I'll go back and look it over again. I have noticed that the deck is slightly dished at the edge as if this area is sinking. I was going to look at this more closely but there does not seem to be any significant related cracking of gelcoat or glass around the perimeter of the deck and only some minor stress fractures at a couple of the stanchions.

Doug: I would examine the areas around the stanchions closely before I cut any holes. Once you cut them to finish the job you may end up having to refinish the entire deck. Its better done as part of a wholesale renovation of the deck repairing any and all deck deterioration. Pictures that I will be posting this weekend will include the beginnings of refinishing the deck. So far I only have a coat of epoxy primer on the deck and I'm waiting for warm spring weather before I restart that project. Spring doesn't happen quickly since we are so close to the open ocean and its temperature keeps us cooler in the spring that nearby inland areas (in the fall its reversed with the warm water keeping us warmer than inland areas).

[Pterobyte]

Peter: I don't seem to have any real deck problems at my stanchion bases and the bottom layer of glass at the bevel seems to be undamaged. But now I'll go back and look it over again. I have noticed that the deck is slightly dished at the edge as if this area is sinking. I was going to look at this more closely but there does not seem to be any significant related cracking of gelcoat or glass around the perimeter of the deck and only some minor stress fractures at a couple of the stanchions.

I had some 'minor cracks' only to find that water was getting to core at the bevel.

I heard that C&C boats cut the core at sharper angle then Performance did and that created a bigger problem.