Building 23' catamaran. Build updates

[stevemid]

For the last week or so, I've been doing what I call regression fairing. That involves going over the whole boat, inch by inch and bogging little flaws in the surface. The next day, sanding it off and marking newly discovered flaws to be bogged on the next round. On the first round the you use plenty of bog, but by round 4 or 5 I can go over the whole boat and use only 1 squirt of bog.

I also made the lids for the anchor lockers. The fore deck is curved from front to back and from side to side. First of all I cut out the 400mm square hatch openings in the deck. The cut outs will be the lids. Then I made a lip for the lid to sit on by taking a 500mm square piece of Duflex and cut a 380 mm square hole in it. This 'ring' was then glued up to the underside of the deck, but first the edges of the hatch opening, the lid and the ring had to be rebated 10mm, filled with bog and sanded flat. (This creates a hard wearing edge and seals the balsa core so water cant get at it.) Because the ring was relatively thin, it easily took the curvature of the deck. To get the lids to take the compound curve, I first kerfed them every 50mm on a fore and aft line to make them somewhat bendy. I then set them in the hatch and weighted down the sides to get them to take the curve, then filled the kerfs with bog. The next day I cut the kerfs on a side to side line, weighted down the front and back edges, and filled the kerfs with bog. Once this went off I had a hatch cover that curves from front to back and side to side. I then put a new layer of glass over the kerfs and the pictures show the result. I still have to fair over the lids and the surrounding deck to create a perfectly matched and faired surface.

IMG_0993.jpgIMG_0994.jpgIMG_0992.jpg

On Thursday I got the big front opening centre window in from Sailfish Marine in Qld. Once I had that fitted, and I could see the arc the window when it swings open. I was able to position the roof and get that glassed down. I got that done today. All the fairing is now done on the boat except for the 100mm around the roof joins inside and out. After I get that done the next step will be to spray on and sand down the high-build primer.
Edit 24-7-13
Here's the anchor locker lids that have now been faired back about 3-400mm in to the surface of the deck. Notice the lip on the fwd port side corner is now gone.
Anchor Lockers Faired.jpg

[weswilson]

Those hatch lids look great!

[stevemid]

Well, I got the roof glassed on, got the glassing faired inside and outside, and also coved on the inside.

Before fairing the cockpit side of the cabin bulkhead, I had to deal with the electrical wires that I had stubbed off in the cabin roof just aft of the bulkhead. I spent half a day playing around with various ways to get the wires into the conduit. I experimented with various pulling boxes which all looked too bulky and an eye sore to me; much like external plumbing on a new house. In the end I decided to cut out holes in the conduit itself which gave me enough room to pull the wires into the conduit, push them along, and then force the corner up into the conduit. This yielded a nicer finished look but forget ever running another wire through the conduit as the holes have to get bogged up and this will block the conduit.

Here's the pictures. The big set of wires hanging down on the port side are from the 200 watts of solar on the roof. This runs down the port side, through the cockpit seating into the settee in the cabin under which will sit the batteries and the solar regulator. The remainder of the wires are all from the ceiling lights, which all run individually down the starboard side, into the gas locker, through the bulkhead, behind the fridge and through the galley cabinet up to the helm station. I've fully sealed and bogged the conduit and the hole through the bulkhead, hoping the gas inspector won't have a problem with it. (I plan to put a drain tube out the side of the gas locker through the side of the hull to vent any gas fumes over board.)

As a final touch I faired in the conduit (which had been well roughed up) in with filleting compound. I decided against glassing in the conduit, thinking the fillets will be plenty strong to hold it in place. I plan on sanding this fair and painting it in to the corners hoping it will disappear.

I didn't fair above the door as I may have a bit of surgery to do on the opening once the door arrives from Sailfish Marine Windows.
Roof Electrical1.jpgRoof Electrica2.jpgRoof Electrica3.jpgRoof Electrica4.jpg

[Apollo]

She is coming up a treat Steve. Well done.

[Horse]

Its all coming together now Steve. Great thread

[stevemid]

Way back in June 2012 we had a nice discussion http://www.ausfish.com.au/vforum/sho...=1#post1396751 about rigging a pennant to the bow eye in the event you every needed to be towed. It has been playing on my mind ever since how to fabricate and reinforce the bow eye so that it would take those kind of loads. A few days ago the light bulb finally came on. And since I'm very sick of sanding I went straight into build mode. My anchor lockers have a centre web and my idea was glass two fibreglass plates to either side of the web and to cut 2 slots in the bridgedeck so that the bottom corner of the plates would extend out the front of the boat. I'd drill a hole through this and attach a shackle to it. I also wanted to make the plates long enough to extend back to the bulkhead at the back end of the lockers so that I could also glass to this.

To make up the fibreglass plates I decided on a size of 350mm long by 100mm wide by about 8mm thick. For the layup I used 6 metres of 100mm wide DB tape alternating with 6 metres of 100mm uni, both 450 gsm. After wetting out all the glass, I left the DB intact and cut the uni into 700mm lengths. I then layered the DB back and forth on itself and layed in a piece of uni on each layer. At the end I had a stack 700mm long which I clamped consolidate the glass and squeeze out any excess resin. The next day I trimmed the edges and cut it in half to give me my two pieces.

Cutting the slots in my finished bridgedeck gave me a bit of butt pucker but drilled a couple of 8mm holes and put the renovator to work. (I would have to say this has been a very handy tool for this project.) I fiddled with slots so the plates would sit horizontal in the anchor locker, then I smeared everything with cabosil bog, positioned the plates and held them in place with a couple 3/4" SS screws. I used the remaining cabosil to create coves around the plates and then glassed them into place using 100mm DB tape on the top and bottom of each plate extending about 100mm onto the bridgedeck and the bulkhead at the rear. I also glassed the tongues to the outside of the prepared bridgedeck. Shouldn't go anywhere.

Out the front I now had two tongues sticking out about 3" and I stuffed the space in the middle full of wetted out chopped glass. This stuff is crap to work with but once pressed together it makes up a nice solid chunk of reinforced fibreglass so I included a picture of it. Before I came home tonight, I bogged it all up and will fair it tomorrow and will include a finished picture then.
Port Plate.jpgBow Eye.jpgPort Glassed.jpgStarboard Glassed.jpgBow Eye filled.jpgChopped fibreglass.jpg

[Chimo]

Hi Steve

Looks nice and solid, should hold a treat. Almost has the look of the beginnings of a wave breaker for the hulls?

Did you consider doing something similar in each hull and then setting up a bridle that you could use for towing if required but more commonly for anchoring to avoid the annoying at anchor behavior that cats tend to demonstrate especially when your trying to sleep?

Didn't see you at Straddie?

Cheers
Chimo

[stevemid]

Straddie? Too cold up there for a while! Speaking of which, I've got bloody roses blooming in my garden in the middle of winter!

Actually I thought a lot about the bridle; I may still do that however it' be a long reach through an access port into the floatation chambers - and it wouldn't work if I get a trailer. (Speaking of which I found a good, low key welder, the guy who is making my jack plates, so.....)

But what I have been toying with is to have a SS "cup" made up to fit over the tip of each bow. This would be fitted with a cleat which could be the attachment point for a bridle. The cup would protect the tips from bumps and chafe from lines, etc
Steve

[gofishin]

She's coming along nicely Steve, well done!

... but more commonly for anchoring to avoid the annoying at anchor behavior that cats tend to demonstrate especially when your trying to sleep?...

Chimo has a good point there Steve - this 'tacking' trait can be annoying in a cat at anchor.

A good (easy) remedy is to have a deck cleat at each bow corner that you use an anchor bridal for (springer cleats will be too far aft). If you're planning on having/using a lot of chain (windlass??), an SS chain/Clevis Grab hook on the bridal works a treat (and stops the dreaded chain clank thru the bow roller at anchor etc)! A bit of rope sock on the 'rubbing' ends of the bridle will help protect your pride and joy too!

Obviously these won't be any good for bridle towing, but will be easy to manage if/when you are on those nice long voyages with lots of nights at sea!
Cheers
Brendon

[stevemid]

She's coming along nicely Steve, well done!

Chimo has a good point there Steve - this 'tacking' trait can be annoying in a cat at anchor.

A good (easy) remedy is to have a deck cleat at each bow corner that you use an anchor bridal for (springer cleats will be too far aft). If you're planning on having/using a lot of chain (windlass??), an SS chain/Clevis Grab hook on the bridal works a treat (and stops the dreaded chain clank thru the bow roller at anchor etc)! A bit of rope sock on the 'rubbing' ends of the bridle will help protect your pride and joy too!

Obviously these won't be any good for bridle towing, but will be easy to manage if/when you are on those nice long voyages with lots of nights at sea!
Cheers
Brendon

Yep I've always used a long nylon rope snubber on the anchor chain to eliminate noise and provide extra shock absorption and take the load off the windlass. Funny, when you're lying there trying to sleep with the mast swinging through 60 degrees, cans rolling in the lockers all you can think of is : I wish I had a catamaran.

On this boat I'm planning on a drum winch with mainly rope rode in one anchor locker and an easy lift ring and float system in the other. Once the anchor is set, I wonder how you would you attach a bridle to the anchor rope?
Steve

[gofishin]

... Once the anchor is set, I wonder how you would you attach a bridle to the anchor rope?
Steve

Split rope bowline Steve. Anchor rode tied off to one cleat, bowline loop in the rode, separate tag line to other cleat & finish off the bowline with this.
Cheers
Brendon

[stevemid]

Split rope bowline Steve. Anchor rode tied off to one cleat, bowline loop in the rode, separate tag line to other cleat & finish off the bowline with this.
Cheers
Brendon

So is that a bowline on a bight? I've never heard of a split rope bowline. So in practice, there'd be a load on the rode, so would you start by cleating off, then tie one of the bowlines knots inboard of the cleat? Then what?
Steve

[Chimo]

Gooday Steve

If it was me I"d set up my anchor bridal with a bowline on a bight in its centre and when anchoring set the anchor as normal then tie a bowline on a bight in it at the spot you would normally make it fast but then secure the two bowlines on the bight with a suitable "dee" that you can lock off. The loose end / continuation of the anchor warp is then tied off to your normal cleat with lots of slack and it becomes the fail safe / just in case to assist long sound sleeping. I love boring boating without unplanned night time activity.

http://www.animatedknots.com/bowlinebight/

Cheers
Chimo

PS the anchor bridal lives on board in a locker and eats very little!

[gofishin]

So is that a bowline on a bight? ...

No Steve. To imagine it, get a crappy long piece of rope/chord & tie a big bowline loop one end. Imagine the other end of the rope is tied to an anchor . Then snip the loop in the middle. Voila, split rope bowline. One knot, 2 pieces of rope (one long ie anchor rode, other short ie rope for other half of the bridle). I think I usually tie a couple of half hitches in the tag end just to be safe. This knot is safe under tremendous load, as i have been using it for towing on occasion for ~30+ years, & my pops a lot before that. Had to use it ~3yrs ago for this purpose (swamped boat in a bar), but probably that has been the only time for me in the last 24yrs. Maybe it was 'his' knot he named for himself! Have never searched for it, maybe it has another name too.

So in practice, there'd be a load on the rode, so would you start by cleating off, then tie

the split rope bowline inboard of the cleat (in slack rode), secure/tie off the short rope (bridle) to one cleat, untie temp cleat where the rode is loaded, and then adjust/centre the bridle and tie off the rode to the other cleat.

Have never used the bowline on a bight for this purpose, but it sounds like Chimo has with good success too.
Cheers
Brendon

[Chimo]

http://www.youtube.com/watch?v=EAyDS1NuK_A



A nice knot tying vid
http://www.youtube.com/watch?v=jbaXAqnyPe0