Core Sound 20 Hull #102

[jaxsailr]

Wow thats a good deal and service.  The 3.5 is a nice engine.  Do they have any more left?  The PDF on the Suzuki 2.5 list the N-F.  Also I have checked it out at the dealer.  The web specs did not list it for some reason.

[wkisting]

jaxsailr... no, this was his last one in stock. Apparently, they neglected to renew their small motor license with Mercury, so he can't get any more this season. I would've thought he was making that up to pressure me into buying, but he mentioned it AFTER I bought the motor. Not sure why it was on closeout for so low. I asked him twice if it was a return or something and he said, "No, it's just been out there on the sales floor for awhile so we marked it down again. But it's definitely brand new."

I found a pic online of the Suzuki and saw that you're right... I could see a F-N shifter. Wish I had known that sooner, as I probably would've checked that one out too, but I don't think it matters much. I'll be glad to have the extra 1 hp and the 8lbs. difference is not too big a deal. But I am a fan of Suzuki engines, as they seem to have zero trouble (well, in motorcycles... never actually used one of their outboards). I don't think we have a local Suzuki dealer for outboards, so service might not have been readily available in this area, which probably would've pushed me back to the Merc anyway.

[Richard Whitney CS#70]

Wes

Had a look at the pictures of your boat - it is coming along nicely. You won't regret getting and outboard bigger than 2hp - I had a 2hp four stroke Honda on my CS17.  It went OK when it was calm - but I had a few experiences of going into a strong head wind with a steep chop where it was not up to the task.  I have changed up to a 4hp 4 stroke Yamaha and am much more comfortable.

I have been out paddling my Redfish King this afternoon.  We are still getting nice warm days even though autumn is coming on.

Hope you enjoy the process of building.

[wkisting]

Hi Richard,

Thanks for the compliment on the boat. I'm a perfectionist so I'm rarely satisfied with my work, but I've been generally very pleased with how this boat is coming out. This is my third build, and I learned so much on the previous two that I guess my skills at working with wood and epoxy are finally approaching a level of skill that can satisfy my obsessive-compulsive desire to get everything just right. Third time's a charm, eh?

Don't you love the Redfish King? I haven't had mine out since last year, but I think it's such a great kayak and it paddles so well. I have a fresh coat of varnish on mine (actually, a fresh 5 coats... I had to sand down to the fiberglass last year to do a repair) so I've been reluctant to get her all scratched up again. 

[wkisting]

By the way, here's the latest pics....

Today I installed the aft bulkhead stiffener, reinforced the transom for an outboard bracket, filleted and 'glassed the face seam of the cockpit sides, 'glassed the centerboard, and added a 1-1/2" wide strip of kevlar felt to the leading edge of the centerboard for abrasion protection.

Kevlar felt is VERY difficult to cut... had to use a pair of those emergency rescue scissors designed for cutting through heavy clothing, belts, etc. Wasn't able to cut my abrasion patch perfectly straight, but I'm going to fair the edges in with thickened epoxy anyway, so shouldn't matter. (There's no chance I'll be able to sand the kevlar... have to build and fair around it with epoxy.)

[Cricket]

For what its worth,

I have used stainless steel tubing let into the leading edge of both rudders and centerboards, then glassed (9oz or so biax) over that after fairing. Small diameter tubing or rod seems right for the shape of a leading edge small boat foil, like a 0012. It has worked very well in preserving the edges from gouges and dings, though eventually you'll need to re-glass.

Looks like you're moving right along with the boat. Wish I could work that fast!

Jim Luton

[wkisting]

Ray, kevlar felt is what some folks use as a rub strip on canoe stems or the centerlines of kayaks. Not sure how it compares to woven kevlar cloth or kevlar-stranded ropes, but once impregnated with epoxy, the kevlar felt becomes EXTREMELY abrasion resistant. In fact, it is impossible to sand it so you have to get it exactly right. Once it's epoxied in place, all other surfaces have to be faired into it. If you try to sand the kevlar, it can stop a sander cold. I think it's partly because the felt absorbs so much epoxy, and partly because the kevlar fibers are incredibly tear resistant (which is also why they will stop a bullet when utilized properly in bullet-proof vests). But you're right that if the fabric itself (without the epoxy) is abraded, then it is apparently less "abrasion-resistant" than nylon. With epoxy, I'm told it's a very different animal. (Try googling "kevlar skid plate" and you'll see they're very common.)

In terms of thickness, I'd say the kevlar felt added the same thickness that 4 or 5 layers of 6 oz. glass would've added... a bit thicker than I expected, since I thought it would flatten once saturated (nope!). So now the leading edge of my CB will be about 1/16" thicker than I wanted, but still acceptable.

Jim, my university is on Spring Break this week, so I don't have to work... I don't normally make quite this much progress otherwise.    I did consider using stainless to protect the CB edge, but I've had this kevlar felt since I built my kayak years ago. I chickened out of using it on the previous two boats because if you lay it wrong, you can never sand it off again. This time, I took the risk, but I think it's going to work. Only time will tell...

[wkisting]

Hmmm... not sure. I know a lot of whitewater canoeists and kayakers swear by kevlar felt skid plates. I figure that the centerboard is likely to encounter similar kinds of damage to what the stems of a canoe typically encounter, so it seemed like a logical choice.

I'll have to report back about how it holds up, but I feel pretty sure it should work. I've seen some pretty sorry-looking canoes that had nearly worn through their (fiberglass) hulls from abuse, but which still had nearly-new-looking kevlar skid plates on their stems.

Perhaps it's not actually the kevlar fibers, but the sheer amount of epoxy it drinks in that makes it so effective as a skid plate?

[wkisting]

Well, here's what I discovered about Kevlar felt now that I've (finally) had first-hand experience with it.

It is TOUGH to sand. I tried 40-grit on a small sanding pad (by hand, not ROS) and sanded hard for 10 minutes... I couldn't see any appreciable difference in the surface. It is VERY abrasion resistant... so much so that I was a bit scared that I had not cut the edge perfectly straight (which also may be impossible... I used a brand new surgical-grade scissors to cut the felt strip prior to wet-out and it was very difficult to cut). The sanding does produce a fine whitish powder, but the thickness of the felt does not diminish noticeably (not sure how that's possible to produce dust without reducing surface, but that really is what happens.)

However, I quickly discovered that kevlar block planes quite easily! Not sure why I've never heard this mentioned before in the kayak building circles, but it is actually fairly "workable" if you're skilled at using the depth adjustment on the block plane. I managed to fair the edges into the board almost entirely by block plane (still had to use some fairing putty/epoxy to finish up though).

So I wonder if both Ray's composites instructor AND conventional canoe/kayak wisdom are correct. Kevlar does appear to be relatively easy to slice (which may be why kevlar halyards need to be protected from abrasion on sharp corners, etc.), but the felt is VERY resistant to the kind of abrasion a centerboard would normally encounter (i.e., dragging on a sandy bottom, for example). Now, if you were sailing in the vicinity of some very sharp rocks, I would guess that the epoxy-soaked rope trick offers better protection, but for the kind of wear-and-tear I expect to encounter, I think the Kevlar is probably far more than adequate... and I suspect it is easier to fair into the board (if you are careful during the lay-up) than the epoxy-soaked rope... though to be fair, I've never actually tried the latter.

Of course, if you lay the kevlar wrong and don't get it in position correctly before the epoxy cures, it would still be a bear to fix. So I don't want to give anyone the false impression that it is entirely "easy" to work with. Much of the quality of the results will depend on how straight you cut the kevlar patch to begin with, and how well you epoxy it in place.

By the way, I now suspect that folks who have told me stories about kevlar "stopping a ROS cold" are actually people who didn't adequately wet out the kevlar (it drinks in a LOT of epoxy). I wet mine out very thoroughly, but I am confident that if a person were to inadvertently wet out only the top surface and then later sand through that, it would raise a mess of kevlar felt fibers that would snag the sandpaper on a ROS probably hard enough to stop the motor in some cases... but that's due to misapplication, I would guess. Properly epoxy-soaked, it shouldn't raise fibers, but it will hold off the sand paper for a LONG, LONG time. And as I speculated in my previous post, it probably has more to do with how much epoxy the fibers hold, rather than any strength inherent in the kevlar.

Thought you might like to hear those observations. It'll be a few months before I can tell how the kevlar protection fares in real-world application.

[wkisting]

Glued up the centerboard case today. Planning to install next weekend, but it'll take all week to attach the doublers for the pivot pin and then fill and re-drill the holes for the pin to create the bushing... etc., etc.

About the installation process... Do most folks recommend cutting the slot in the hull first, THEN installing the cb trunk? Or do you recommend glassing in the trunk first, THEN cutting the slot?

Either way, I'm guessing it would be wise to insert a temporary spacer block to make sure the sides of the case stay perfectly parallel with sufficient board clearance, no?

Thanks!

[Charlie Jones]

Use several spacer blocks in fact. I usually use minimum two, often three. Cheap insurance.

Personally I glue the trunk in place, with some locater holes drilled so I can find it from below. Then I use a router with a pattern bit ( bearing on the lower end) to cut the slot. I tape a strip of wood to the base so the router sits parallel to the sides of the slot, NOT the surface of the hull. Then I rasp the corners square, round the whole edge over and put on a layer of tape.

[wkisting]

Charlie, Ray... thanks so much. That's exactly how I was envisioning it... including Ray's suggestion for a full-length spacer.

I'll drill the locator holes before I epoxy it in, then cut from below with a flush cut bit on the router... then switch to 1/4" roundover and add tape.

Charlie... how far in do you insert the tape? Just enough to cover the rounded edges? Doesn't the tape thickness consume some of the blade clearance, or is it too little to matter?

[Ken_Potts]

  Wes,

  You're already convinced but I'm going to chime in anyway.  I didn't use spacer blocks to make sure the sides of the centerboard trunk were parallel.  I ended up sanding and sanding to get the centerboard to fit.  In the end things worked out well but you will save a lot of work by using spacers.

[Charlie Jones]

I run it over about an inch, maybe a tad less. Enough to be sure it covers the edge and has a good lap onto the inside of the trunk. I scrape the edge with a hooked scraper, sand the edge then by hand, then add resin to make it smooth. Adds maybe a 32nd of an inch- not enough to matter.

I also coat the inside of the trunk ( before I put it together) AND the board with graphite filled epoxy by the way- helps things slide a bit better.

[wkisting]

Well, I did think to coat the case interior with fiberglass and three coats of epoxy before gluing it up, but I didn't think of the graphite trick. I have some graphite powder on hand, so I may still coat the board. Thanks for the suggestion, Charlie.

Do you screw (or fiberglass) the cb sides to the king posts, or just glue them? I have the case epoxied together, but I'm wondering if I should also fiberglass tape the seams or insert screws. I suppose most of the lateral force on the board is probably transferred to the hull panels rather than the case sides anyway, no?

Ken, I installed two daggerboard slots on my last boat, but they were built from solid wood with very little flex so I thought I didn't need the spacers--but even then I ended up sanding as you did. As soon as I handled this CB case, I could see that flex might be a problem when installing. I agree spacer blocks should save quite a bit of labor... wish I had thought to do it last time, but that's what's so great about building boats AFTER you've already built a couple of boats... you learn from past mistakes 

[Doug Cameron]

On the centerboard:

After the Everglades Challenge (which is several years of wear and tear because of oysters and beating in shallow water after sleep deprivation), I found the forward corner of the centerboard and the rudder were worn, though not badly.  I put a thin 10 oz epoxy and fiberglass abrasion pad on these corners and sanded the upper edge of these "patches" until fair with the rest of the board.

[wkisting]

Placed an order for all the hardware, rigging, sails, etc. from Graham and Carla. Not only are they incredibly patient and helpful, but you were right about their prices too... some of their hardware is spec'd at prices up to 50% less than West Marine! (Granted, WM is always overpriced, but I still couldn't believe how reasonable the B&B prices are... and of course I'm delighted to support Graham and Carla.)

What size/style of trailer do you recommend for towing the CS20? Probably better start looking into that now, as used trailers (in good condition) appear harder to come by down here in GA than they were in the Midwest.

[Ken_Potts]

   Hopefully Paul Stewart will chime in.  He recently bought a trailer for CS20 #103 here in NC (Greensboro, I think) just before the Everglades Challenge.

   I agree with Ray about buying a trailer that's not intended for a heavy boat.  My trailer was new-surplus (thanks to a tip from Oyster) and if I remember correctly it was originally intended for an 11-14 ft power skiff - I bought it for the weight rating, not the length.  I moved everything forward (especially the axle since I don't have a 30HP motor hanging on the transom).

   When I started looking for a trailer I was calling people and telling them I was looking for a sailboat trailer - Mistake.  When you say "sailboat" to a trailer salesman she will hear "Keelboat" and think you have 6 foot draft and need an extendable trailer tongue etc. and all communication gets really difficult.  When you talk to somebody about trailers remember to tell them that you've got a 20 foot skiff with a 4hp (or whatever) outboard.  You'll do fine with a trailer built for a 15' or even smaller powerboat.

   But once again - You might want to send Paul Stewart a message since he bought his trailer so recently and you're in the same general region.

  I also agree with Ray about buying new.  My new trailer cost $800 which is a lot of money but I know I won't have to replace it.  Ever.

[wkisting]

Thanks guys... I asked for a price quote on trailers that meet the criteria you mentioned, so hopefully the nearby marine dealer will know of trailers available. I'll definitely opt for rollers, Ray, as I had them (and loved them) on the last boat trailer.

About the centerboard... do most of you paint it, or is it preferable to leave the lower 2/3 unpainted for inspection purposes? (Obviously, I'll paint the top 1/3 so that it doesn't look odd and "unfinished" where the lever arm sticks up out of the CB case. I'm just wondering if it would be easier to maintenance the board if I leave it bare epoxy. Then, when I notice dings or deep scratches, I can just rough it quickly with sandpaper and dab it with epoxy. (Good idea, or no?)

[Ken_Potts]

The part of my centerboard that sticks up in the cockpit is painted.  Everything below that is epoxy-coated (with graphite filler).  I didn't see a need to paint a part that would get virtually no exposure to the sun.  Plus the epoxy/graphite is more slippery than the paint I used.