hokeyhydro

The gudgeons I used had a 4 bolt array, although I used fat ss sheet metal screws instead of bolts - no access to the interior on the catamaran hulls.. Four bolts may seem like a lot but an empty hole would look weird and a boat the size of a CS-20 can generate a lot of twist and stress on the rudder assembly when you're hauling tail. Pivoting tiller handle will be nice. You might want to consider a hiking stick as well.

Do the mini-paws and Spindrift use 6mm ply? Might be able to shave weight with 4mm, or if you can find it 5 ply 5mm. I use to get 5 ply 5mm for my race boats from Harbor Sales when they had it, which was about a 50/50 shot.

But then we have the same problem as bolting a fitting on w/locknut & washer - how to get the rivet washer INSIDE the mast tube.

I was landlocked, but helped my daughter launch her standup paddle board and she zipped off with more'n a dozen kayaks and a couple canoes for the annual NY day paddle on the Trent & Neuse.

Well, if the stuff is invading fast than we need to BUILD MORE BOATS to stay ahead of it.

I have used 5 oz Kevler. Since it doesn't go transparent working the air out of the layup is a problem. I used fluted/ribbed rollers that are normally used to roll out chopper gun layups but I found the fluted/ribbed roller very handy to work ait out of fiberglass mat that I used to beef up production molds. And the roller did a fine job getting ait out of the kevlar layup as well. Keflar is good, but I think xynole (?) is better for abrasion resistance. Course both xynole and dynel (another abrasion resister) soak up resin like a sponge, so I would go with 3X or 4X cloth weight to estimate finish weight. Even with Kevlar and glass to get the surface filled and smooth the finish is closer to 2 1/2X cloth weight. Epoxy by itself is fairly hard. In your case I might go with 4oz or 6oz FG on the bottom, say up to the design waterline. That would give more damage resistance and save a bit of overall weight by skipping FG on the sides. My daughter's wood/epoxy beach catamaran just has FG tape on the keel seam and after a year of sticking it on sandbars and dragging her up on broken shell littered beaches I need to scuff sand the keel area and recoat with varnish, but the hull and glass tape are fine.

Like your 2paw rudder, Peter. The Gougeon Bros. had a dagger board style rudder on i550 they redesigned to run the Everglades Challenge so they could jack it up for the skinny water - had a lifting bulb keel as well.

Have not built *that* rudder, both both kick-up rudders on the catamaran I built my daughter have removable tillers. One bolt so the tiller can stay down when the rudder kicks up - remove bolt, tiller comes off.

I've used cedar or cypress. Or pine. Whatever turns up when I shuffle through my breasthook size scraps.

Yep, a brain fart. Word of warning, the BF per day increases with age. My fav &^%$#&( BF is when I mix a batch opof epoxy and then remember I forgot to: A) Cut the part shape the part C) attach a cleat or whatever is required to fit the part. And I have a pot of goo cooking off . . . YEEPS! Anyway, you caught it before glue so crisis avoided. Good job. Young uns helping is a big plus. They will never forget those shop days with dad - never.

Beautiful! Your trim tab pockets are truly a work of art. Trailing edge of the bottom appears fairly sharp as well - closer to cutting edge is faster. While epoxy/fiberglass is green on that edge I add epoxy thickened well with milled glass fiber to give that edge a crisp point. On normal frozen snot pulled-from-a-mold boats cleaning that edge up can add a few knots.

I built oars out of white ash. One could use these beasts to repel boarding pirates, but they are way too heavy for comfy rowing. Next set from spruce, just lumberyard stuff. Fairly light, nice looking, an strong enough = no way my skinny tail can haul them hard enough to bend or break them. Fir may be heavy - especially on a 10' oar. Heft a few pine/spruce boards and go with light. Assembly? I did the looms, glued on paddle parts - shaped. I did 8-side the looms above the paddle parts before attaching the extra pieces. Easier - ran it thru the router. For the paddle end a portable belt sander with mega-grit paper came in real handy. Also whacked parts that didn't look like an oar off with a drawknife.

If epoxy was squeezed out you had plenty. You did fine - I know I wouldn't get all fussy about a perfect bevel. I would plane some, decide it was close enough and go for the gobs of spooge method to lock it down. After reviewing a couple B&B plans I figure there's a large margin of error AKA safety factor in the design and scantlings. Take a breath and move on with confidence

I dig the cool rollover frame. Better than my usual system, just flip the bugger. Usually by myself, or maybe Milady lending hand which costs me kitchen pass points. Beautiful hull. Pretty work. Only 20' so your boat rollover pals will have to draw straws for first voyage crew :-)

I'm confused. Transom angle to me is the angle of the transom with respect true a vertical plane, as in how much the transom tilts aft. Bevel on the underside of the keel batten should match the angle of the bottom panels AKA deadrise. Are you saying the deadrise at the transom is 8 or 9 degrees? I'd have to check my plans but I thought the transom station deadrise was around 12 deg. As for center temp bulkhead being off 1/4" - eyeball the hull and if you can't see any obvious flaws in the fairness of the chines, then no problem. I doubt a1/4" affected anything. Just hurry along so you rip out the temp bulkhead - once gone not even you will notice the tiny error. :-)

I need to make a SUP paddle for my daughter too Would really appreciated details on the one you made - if you would be so kind to share detailed dimensions and construction picures if possible. Thanks TomH PS did you build the board as well? If so, what plans did you decide to use? Built the SUP - a Kaholo from CLC plans (Chesapeake Light Craft). Board came out heavier than CLCs advertised weight of 32 lbs, and many other builders had the same result = about 40 lbs. For the SUP paddle I made a teardrop shaped blade from two layers of 1/4" balsa wood. I used C grain balsa available from Sig Manufacturing, but I don't think C grain is absolutely necessary. Blade sheathed in 4oz fiberglass. Shaft was 7mm X 14mm western red cedar blanks with BM groove cut in one side and then I planed a taper on the handle end. I get some pics up soon, and you can email me wjhuson43@gmail.com for more details.

I like that idea, Peter. Two piece for ease of transportation and storage & 1/2 wood to save a few AL $.

On my plans for smaller CS boats Graham has details for all-aluminum masts and wood as well. Be interesting to have the actual weight of finished aluminum masts for a CS boat. Birdsmouth wood can be fairly light. The catamaran mast I built runs about a pound a foot with all attachments, and built a couple BM shafts for paddles my daughter uses on the stand up paddleboard I built. The pro at the SUP shop in town was amazed at how light the paddles were. The slightly over 6' paddle my daughter uses weighs 22.5 oz which is only a couple ounces heavier than a commercial graphite paddle that cost about $400.

I used cypress for a 21' mast on a catamaran. Built the mast hollow using the birdsmouth method. 8 staves 7mm X 14mm. My birdsmouth mast had several scarfs (splices) since boards were only 16' long. 8:1 scarf ratio is fine, and I staggered the joints so no two joints among the 8 staves lined up. I think a solid mast on a CS-20 would be far too heavy. Especially in doug fir. Even in spruce or lighter but expensive sitka spruce I think a solid mast would be a tonner. If you have a table saw or router you do a birdsmouth build.

Stitch & glue panels are normally edge-rounded where panels are stitched together. This allows the panels to get squeezed tight by the wire stitches without one sliding off and causing a lopsided joint. The round-off is sort of like a bevel on the edge except rounded, of course. Viewed from the end an imaginary centerline on each panel edge (center ply is a good reference) should intersect at the middle of the joint, just like they would if you beveled them. The rounded edge allows the panels to be shifted a tad as you "massage" the joints fair. And after you wind the hull to level her out you may have to tweak a few joint areas again before locking the panels down with epoxy.

Might switch this topic to B&B Yachts Forum.

What is your preference for handling lines, such as sheeting lines etc? On the wood/epoxy catamaran I built for my daughter I used line from West Marine, double braided line claimed to be sheet line. It tends to curl up when running through a block or an eye. Annoying. Halyard lines are the same same stuff, same problem. It is also rather slippery which means one has to wear cloves or just squeeze and tough it out when the line is under a load, and lemme tell you, a sloop rigged cat in a breeze can be a handful = pun. What line would you choose for: Sheets: Halyards: Vang AKA Kicking strap: Other sail adjustment lines: Target = CS-15 future build

Scott, opportunity knocks! Get your wife a nice quality spiky wheel and make her a believer in fine tools! Next time you haul a $$$ fine tool home she'll understand and approve instead of .... *shriek*

An engine bracket moves the engine weight aft, so check with Graham about balance etc before going that way. I like the bracket on my frozen snot boat because of the full transom. Harder to swamp the boat with a rear entry rouge wave when you have full transom. At least once a season on the Carolina coast a boat gets pooped with wave coming through the notched transom.

Your trim tab pockets are a work of art! At first I hated the trim tabs on my Parker because early on I fat fingered the control buttons and dropped one down but not both. I quickly discovered they work like ailerons on an airplane = instant bank into a turn!. But now I use them quite often to make incremental adjustments in ride attitude. Production boats with those large engines are probably fiberglass and heavy. The Okracoke is wood and lighter, so do not be surprised if the 115 cranks it faster than 40 MPH. I'm not sure about the newer 115 Yamis but my vintage series was underrated by Yamaha which is where the extra horsepower came from. Now that she's old with a gazzillion hours on her she's probably close to the 115 number.