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Steve W

Core Sound 20 Mark III #3 "Jazz Hands"

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Chick, I'm learning from all these threads. My Dad has had failing health for some time and I've been traveling a bit for work, so progress is slow but steady. I have the stringers on and I will tape the panels together this weekend, hopefully to go 3-D next weekend. I am working on the centerboard and have it shaped nicely. I had a nice idea that worked well that made the job much quicker. I didn't take a picture during the operation, but this pic gives you the idea:

 

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I took the X-section Alan gave me and copied it and spray adhesived it to a wooden blank and cut it out as shown. I put a Dado blade in and angled it to match the proflie (its true you can only do this on one side, but even flat in steps worked well on the other side). I clamped a stop on my out-feed table and in short order put the profile on the board that equaled this shape. Once I had the shape on both sides I cut the "block" off the trailing edge with a band saw. Next, I cut the board off where the lead shoe goes and traced it's shape onto the end and made short work of the shape.with a hand plane where it tapers.

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Chick, when I was at B & B Alan cut me the mast plugs for the base. I watched that machine and wished I'd have brought a blank for the centerboard, because I think it would have taken him 5 minutes to shape it and whatever he charged would have been worth it. At the time, I thought the level 2 kit had a plywood foil. Back home, I thought there must be some way to automate part of this and this is what I came up with. It's no shop-bot though.

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Chuck, I was feeling a bit guilty about buying the kit. I built the Spindrift 11N as a practice for when I built a "real" boat. I really wanted to build it from scratch. Given the way my life has gone since February when I picked up the kit, I'm glad now the parts are cut out. But I really do enjoy woodwork and have built some neat stuff over the years. I'm having fun so far!

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Clever solution!  I used a router, and some fancy templates.  It got pretty complicated, and the results weren't perfect.  I think you're on to something.

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post-3770-0-81750200-1446769128_thumb.jpg

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Slow progress, but progress. This weekend I glued stringers. Around here Douglas Fir is really hard to find. I'm very worried about the wet environment of the water ballast tanks, so I wanted something better than just the pine they sell around here. Luckily, I found some really nice straight kiln dried untreated DF 4 X 4 posts at Lowes a while ago and bought a few for use. I've gone back a few times and sorted through the pile and you might find one out of the stack with minimal knots and slow growth rings. Anyway,  I set up the shop last week to rip stringers, and this weekend I glued. Not too exciting, but progress nonetheless. I keep talking about going 3D, but I can see this cockpit module is a bigger job than I thought. Alan had sent me an update to drill holes in the baffles in the water tank, so I got that done.

 

Now my question is to those pioneers before me.....once the module is made, you have the need to fiberglass the interior of it, which has a lot of complex surfaces. I assume the top underside is un-glassed, but I could be wrong. It seems that with the module upside down, but with the top inserted with plastic coating it to prevent it from sticking, the sides of the baffles and outside of the tank would be glassed. Did you glass over top the upper stringers or just up to them? At the bottom, did you just pinch the wet fabric together and then once it was dry reopen the drainage holes? I'm assuming that after all this you have to tab the module to the hull once it is in place.

 

Another question that may answer itself is does the heavy glass strip get done before or after the module is glued in? It seems it would be easier to do it first.

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Steve,

 

Top underside of cockpit sole. Yes glass it. I don't think you need the cockpit sole to be in place to do the glassing of the ballast tank if fact i think that would make the job more difficult on the outer bays because the stringers are on an angle. I would glass over the strigners but it's more important that there are no pinholes and that everything has a durable coat of epoxy. 

 

You see, the ballast tank doesn't really need fiberglass but the fiberglass forces there to be a certain amount of epoxy thickness on all the parts which is desirable. If the glass goes on with lots of air bubbles and voids then I think it would have been better if it was just epoxy coated with say 4 or 5 coats because i would be worried about water getting behind the glass in those voids. To further confuse you, I've also thought about glassing the module pieces both sides before even beginning the assembly of the module but it would require widening all the slots and things but maybe doable. 

 

On the limber holes, I cut the glass around the opening after it's green. Then epoxy coat the end grain with 3-4 coats before installing. I would be coating all end grain before putting the module in in case somehow there ends up a void with bare end grain.. 

 

We're all still working out the best ways to put these things together. Bottom line is that it has to be coated everywhere with a nice thick coat of epoxy.

 

Yes the module must be glassed to the hull. 

 

On Peter's boat (http://messing-about.com/forums/topic/9519-core-sound-20-mk-3-5-started/page-2) We glassed his keel and chines before he came and got his kit. This is the best way and the way the final version of the manual will show. Also he glassed the hull in the ballast tank area before installing the module. That seemed to work well also means that the only thing left is the glassing of the module to the hull. 

 

-Alan

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Hi Steve,  what Alan said!   After 4 full wet gooey coats of epoxy in the ballast tank we painted a full wet coat of Sherwin Williams Tile Clad epoxy paint.  It is BRIGHT white and if there were any pinholes I hope they would show up.   I taped our joints on the module before installation, but still had to tape the actual module to the hull.  That is the inverted ribbon toss I spoke of.  Understand it may be a Olympic event in Rio 2016.   

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I have a question about the pennant hole in the centerboard. After I got the board all together, I realize there is a lot of weight on the pennant, as evidence by the mechanical advantage built into the pennant design. My plans don't show details, but I would think at the very least the pennant hole should be filled and re-bored, and possibly sleeved to prevent the stopper knot from ever tearing it out. It seems that with the board up there is an awful amount of pressure on it. What does everyone think?

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Hi Steve, I filled mine with thickened epoxy and redrilled the hole. I also sanded and chamfered the hole that the pennant passes through. Not much mechanical advantage here and quite a lot of load on that area.

Quit messing with the Internet and get to work!

Jay

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Jay, all these posts are from work......when I'm home I'm actually working! I do worry about the load. A lot of weighted foils have the line attach further down, which of course adds drag. I assume our designers thought this through. I just want to make sure I build it properly. BTW.....wee need some video of Southern Express!

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I have contemplated a flexible stainless wire rope for the pennant, with a rope tail for handling from the cockpit. I am also worried about the small lever arm between pivot and pennant hole compared to the long lever arm and high load at the end of the centreboard. I would hate for the pennant to fail underway. Either that or a really strong plaited rope. What do others think?

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You know, I originally thought the board pennant under more load than it actually is. I can grab the block and lift the board with no mechanical advantage . With a muti part cascading tackle the board load is comparable to the other loads, sheet, snotter halyard, they are all very harmonious. I did take some effort to prevent chafe, but I guess that is pretty standard.

I mounted a ball mount for my Sony Action Cam on the mizzenmast. I hope to get some cool videos next time out! Presently on a work trip flying around in the Gulf.

You guys are going to love the way the boat performs, I am new to boats with this much sail area with a very easily driven hull. It is a heck of a lot of fun!

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Steve. I guess you're about to glass your module? I would definitely glass all of the plywood surfaces and epoxy coat everything as Alan says. Do it all outside of the boat. You can do the angled panels on the "bottom side" with the module upside down. I didn't glass over my glue blocks, but do resin coat them including end grain before installation. Be sure to "scuff" all of the resin coated surfaces that you will tape onto when you glass the module into the boat. To me, this module glassing was the mostest, un-favoritest part of the build. From here on, it's all fun and games!

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Drew,

I will be using 4mm Amsteel for the first stage of my c/b pennant.  At the board it will be secured by a knot/hole as is specified for the rudder.  Amsteel is the easiest thing to put an eyesplice in (a Brummel hitch).  There are plenty of videos on the process on YouTube.  I will be using a cascade system for the mechanical purchase needed.  Not sure right now, but it'll probably be 8:1.  The beauty with a cascade system is that this will only require three single blocks.  (Those darned double and triple blocks go up in cost astronomically!)  For the last stage, I'll switch to FSE Robline's "Dinghy Control Line", 4mm.  This does not splice worth a darn, but it is near zero stretch, is easy on the hands, and comes in pretty colors.  The downside to a cascade system is that it requires a lot of "throw".  I'm just going to let the system run alongside my c/b trunk, and damn the aesthetics.  I hope to have photos of this in a month or two (or three).

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This weekend I got down to doing some serious fiber-glassing. I glassed one side of my centerboard, and the inside of the C-board case, both halves.

 

I have some questions.

 

1. On the C-board, I followed Alan's C15 video and let the fiberglass drape down on the leaving edge and stick out on the trailing edge. At the top, I carefully wet it down. I'm happy with the shape, but I think I may wrap tape over the leading edge. It seems a bit vulnerable there. Anybody have any advice here.

 

2. I put a fillet in the c-board trunk and let it go green and then put in the glass. It shaped better and easier than I thought. This morning I gave it all a fill coat. My question is that at some point I'll have to glue the "cover" to it. Do I coat the mating surface to seal it? I assume so.

 

3. Did you guys leave the interior of the case unfinished or did you paint it?

 

4. When you mate the "cover" to the C-board case I'm assuming I use thickened Epoxy. How do you clean up the squeeze out on the interior seam?

 

5. I'm thinking of applying the glass cloth to the interior of the water tank ahead of assembly, and then once it's together filleting and taping the seems. Did any of you other builders do this or did you just work inside the assembled cockpit? I feel like gravity is going to work against me.

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My CS-17 case was completely sealed, without any board arm slot in the case cap, but essentially it was similar.

 

I used the saturated rope trick on the board's leading edge, after sheathing it with fabric. Once the line had cured, it was faired in with thickened epoxy and painted. I never waste epoxy will "fill coats" unless it's going to be a bright finish. It's faster and more economical to use a thickened mixture to fill the weave. For your build, I'd surely overlap the sheathing from one side to the other, just for more protection. Some like to use metal along the leading edge. I've used a number of things over the years and stone dust (yeah stoe and decomposed granite is a favorite) formed into a rock hard (literally) leading edge. You can bash pretty much whatever you like.

 

I'm not sure I understand the coating mating surfaces question, but I made the case a bit differently then the plans. The hard part is completely sheathing the inside of the case. I sheathed both sides before they were married to the king posts, then used a 4" tape to seal the ends, connecting the sides and king post sheathings. Yes, you'll want to scuff up (or work green) any previous sheathings or epoxied areas, before subsequent sheathing/coatings.

 

You can paint the inside if you like, though it's not going to stay in there long, with the board sliding up and down. Making it smooth is more important.

 

The case cap I bedded down and used screws on fairly close centers to insure it would stay down, but could be removed for service. If you epoxy it down, you'll tear things up trying to get in there for some reason (like a bent pivot pin). My pivot pin was purely internal and didn't penetrate the case sides, so it couldn't leak. The pin was welded to a length of stainless bar stock and fit in a hole on a reciprocal length of bar stock fitted on the other side. The board and the two pieces of pin/bracket assembly were lowered into the case as a unit and screwed to the case stiffeners along the top of the case. This is a trick I blatantly stole from one of Phil Bolger's designs (years ago) and it's too cool to not use. On board hoists I use a setup I stole from Phillip Rhodes. These guys were a lot more clever than I.

 

In a nutshell, there's lots of ways to skin this kitty, probably with no clear winner. Just use your head, maybe some common sense and you'll be fine. Lastly try to keep in mind future needs, like repairs or replacement of stuff. This is the reason I bedded the case cap. My hoisting system is inclosed in the case (mostly), so a turning block, lanyard and other things will need replacement at some point.

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You may want to check-out my building thread on Summer Breeze about these questions. http://messing-about.com/forums/topic/9480-core-sound-17-mk-3-summer-breeze/page-2

 

Meanwhile, I'll throw in my "two cents worth". 

 

1. Wrap the leading edge as you do each side. You may want to consider the "rope trick" that Alan suggests.

2. Look at how I did it. Not sure what you mean about "mating surfaces". I think you mean the "flange" around the edge that the other side of the trunk mates to. I     actually glassed over these at the same time as i covered the trunk sides. Give everything a couple of extra coats of epoxy.

3. I didn't paint it, just plenty of epoxy.

4. Yes, thickened epoxy. I used a 1' paint brush on a stick to reach into the interior seam.

5. Once again, check out my thread. It's MUCH easier to glass the module outside of the boat. Didn't we talk about this earlier in your thread? It would be helpful     to go back and read over it again.

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Thank You.

 

1. I decided against the rope trick. I have a sea pearl with lead shoes just like this. They even weigh about the same. They've bounced off quite a lot of rocks, bottoms, etc and the only thing I've had to do is fair them with thickened epoxy and re-coat since there is no water intrusion into lead. I can imagine on a solid wooden centerboard like the CS15 that this rope would be desirable. I also found the section so fine in the lead casting I would have removed a lot of lead to fit even a small rope. Did you do add the rope Chick?

 

2. I didn't notice the taper you had put in your centerboard framing. I wish I had noticed that. That is clever. So mine are just like the plans in that the glass is trimmed off the inside face (that would be the top as the trunk is laying down). The top of the framing (laying down) is the mating surface I speak of. I think I'll seal it super good and then let if fully cure and then sand it before mating the other half. I like the paintbrush idea for cleanup. I think I'll have to mostly use screws to clamp now that I think of this and I'll be able to clean it out good.

 

3. Par, you used thickened epoxy to fill the weave? Did you then just squeegee it out? On my 11N I honestly don't remember glassing the inside of the trunk, although I know I did.......getting older I guess. 

 

4. As for the module.....I guess what I meant was to pre-coat all the faces with glass flat on the bench before final assembly. Alan sent me a addendum that has big holes in the baffles of the tank to add (I assume these are to facilitate drying) and I already added them. Yours might have been factory cut as  see they are there. In cutting out the fabric for facing I realize gravity will be working against me big time now. So my current thinking is to preface all surfaces of the tank and then carefully trim the glass at the green stage so the joints can slip together. Then I would fillet the joints and then add tape to the seams after the module was assmbled. I could also wrap the glass up around the stringer easier this way, all the while working neater.

 

5. I will add that while it seems I'm not doing much, I am managing my space. I did get the hatch flanges mostly glued and I'm also working on the rudder.

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