building log # 634

[Thomas]

I got a start, put a couple of weeks into ,who knows time fly's.
I zip tied the boat together but see some buckling in the front of the boat , frame F 18 and Frame 53.5 did not line up right . had to change the line up on the shine so the side hull sits on top of the bottom panel for 3 feet to make it work . I have a lot more zip ties to install , it all should work out soon when it gets more ridged.

[Mist]

It’s looking good. I found a few inconsistencies when installing the frames on mist too! The highs and lows in the building panels were slight. I felt it was more important to keep the hull panels fair and fill the gaps between the panel and frame. I think I added approximately 1/2” insert at frame 53. Keeping the the hull panels fair is key to minimize fairing later in the build. Have fun!

[admin]

Looks like a good start, Thomas!

If you look at my build log here:

http://www.nbayracing.com/i550buildPage3.htm

at 3.08.09 "Go Day" there's a shot and brief explanation of how I dealt with the issue, by sistering on another piece cut to fill the gap and fill out a fair curve. I guess it's as legit as any other method.

I can't remember, but I thought Timber or someone re-drew the plan set to address this (pretty minor) issue? Anyone remember?

[Warren Nethercote]

Good to see another build log. I was getting lonely ....

Where are you situated? Perhaps you could add a signature block to your profile settings.

[monsters inc]

My scarf line ended up at the front of the side panels. The later version of the plan set bulk heads were more of a fair curve in the 18 to 53.5 area. Regardless, take time , pull and adjust your zip ties as needed. A bit of fairing is ok , and the more bulkheads you can get in position , the easier it is to use a batten to adjust things . Looks scary at first, but I found it was cool to see the whole boat come into line. Tabbing things over the edge of the hull was awkward, but when you finally jump inside the hull it will go faster... Just be careful not to step on your forward hull bottom split. Throw down something to distribute the weight . Be prepared to be neat and there will be a lot less sanding for the taping. Good times...Mike

[Thomas]

I been busy at work so little time was spend ,but moving along .
No gluing yet , too cold still , race committee at the sailing club this weekend , so next week will be it .
I moved the 18" frame to 16 " slightly making narrower. Added another frame at 35 " and I have a very nice fair curve on both sides .

[admin]

Warren, Thomas is situated in Georgia USA (see thread in Welcome to), someplace where it's warmer than here, with cattle, seemingly of the beef variety.

[Thomas]

I have been busy gluing and working my way towards the middle from both ends of the boat , my arms are not long enough . now I got some strength I can step into
the hull with some plywood to support my weight . I built a rather sturdy mast step .

[Mist]

Boy! Thomas, you have been busy! Great job!

[Warren Nethercote]

Thomas, nice job on stiffening the frames. If I had done it that well my dimensional control would have been better.

[monsters inc]

Nice work! I hung from my rafters to get in the hull, to fit the bulkheads. You are so far past that now, no worries. Just as an aside, Mr Nethercote mentioned dimensional control. The Moore 24s were asymmetrical by 1/2 an inch. Still an awesome performer.... 550 should sail well, I know my boat is within a quarter inch over eighteen feet. I placed a drywall screw in the stem and measured off that. Most helpful as a confidence enhancement... Chain plate supports especially. Again , nice work!

[Thomas]

I did the unthinkable , a centerboard trunk , had to try it ,it's the only chance I get . I think if all goes wrong I will be able, at a later date to go to a dagger bulb keel.
The centerboard trunk will be open into the cockpit floor , I will seal the bottom with seal slot strip , Not sure what kind of board ,how much weight or design ,but in time
it all will happen . The Lightning class uses a 130 lb board so all option are open .Yes I am worried about the wood I added , more weight.
I also cut the cabin top out and started working on stringers .
I found a used bass boat trailer for $300 , aluminum, once I take all the unnecessary parts off and cut extra parts off it will be nice , 18 foot long , 6 foot inside the beams tows great ,lite .

[Warren Nethercote]

Thomas you might want to look at the Callaghan-designed Bluemotion 55, which has a ballasted centreboard with about 120lbs of lead in it.

http://www.bluelightning.co.uk/bluemoti ... ion01.shtm

One of the videos of the boat shows a self-righting test. A key safety note: make sure your centreboard includes a positive lock-down arrangement. If the boat capsizes beyond 90 degrees and the board retracts the boat will go turtle, and there will be no easy way to get it back. I have seen a Lightning stuck that way after a death roll when the crew didn't cleat the 'board down' pennant, and Leon (PhattAss in South Africa) had his i550 go turtle and flood after a knockdown when he hadn't locked the keel down and it retracted.

The Lightning centreboard is simply a stainless steel plate with faired leading and trailing edges. It is a pretty inefficient thing: not a problem with a one-design, but you could do better with a foil-shaped board. The width of your slot suggests that a foil is your intention.

The other question to ask would be how much lead went into the bulb-less keel on Meade Gougeon's i550. Doing something like Meade would be a good approach, but pivoting rather than as a dagger board.

Edit: Even better, an earlier Callaghan dayboat design with a ballasted board, with some study plans

http://www.bluelightning.co.uk/Highligh ... 0Plans.pdf

[Thomas]

Thank you Warren all info is appreciated. Yes I will make a profile foil with or without weight , even so my brother tells me I do not need weight in it .Like I said I have a lot of options .
I will glue a couple of guides into the centerboard trunk inside once I got a foil shape to keep it tight against the walls .
Thanks again

[Thomas]

progress , I turned the hull over suspending it from ropes ,bracing the hull with a couple of wood to stabilize it . Not too many low spots should be easy to fair out .

[Thomas]

Question please : What are the best dimensions for stainless steel flat bar for the chain plates ?

[Warren Nethercote]

There is probably no 'best' way but it would be hard to do better than Kevin's design .....

[Marino]

Thomas you may need this layout also, for the strut location.

[admin]

That drawing from Kevin was invaluable. I used it "to the T" and my rig is still standing. I mean when it's up....it's on a mast rack right now.

But when it's up, it stays there.

[Thomas]

Yes i have been sanding ,gluing ,laying up glass, sanding some more and painting the first 2 coats of primer ,feel worn out !!!
Also working on the foils ,rudder and centerboard blanks for now , the centerboard route I choose is tricky to say the least , trying to put the bolt through and holding the board from the top impossible alone . 43" by 17.5 " below the keel is what fits in the box , no ballast yet .
Spring is here finally and I been sailing my Hobie Cat every weekend ,just love the little catamaran with 320 lb of weight .

[Thomas]

What would be a good aluminum mast to use ?
How would I find a used Viper 640 mast ?
Does anyone have an mast for sale ?
Thanks

[Thomas]

I have been banned to grind and sand Sunday morning before 9.00 am.
Here is another pic ,board in the box .

[Marino]

Because I am purchasing new sails, I am going with a Dwyer DM5 mast. A number of owners are using the DM5. Originally I was going to use a viper mast and still have it. Took the inner sleeve out and convert it to a double spreader system. Check with the viper class site and post a note for anyone getting rid of one. Would sell my to you, if wanted, but I live in Toronto.

[Marino]

Most owners are using the DM4, not DM5. Typing mistake.

[ryderp]

I use a Dwyer DM4 mast and have been very happy with it. It has been very durable. I built my own composite spreaders and use stainless shrouds and fittings. I have a DM5 section for my boom.

Phil