Blackrock 24 (Build)

Discussion in 'Wooden Boat Building and Restoration' started by LP, Mar 12, 2013.

  1. LP
    Joined: Jul 2005
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    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    The sails have arrived!

    I've hoisted both the mizzen and the main independently, now. I've only got pics of the main hoisted. The mizzen really extends beyond the stern so I've got some work to do with controlling it and maybe some modification to the plan will be necessary. The main hoist is looking good. I don't have the mast set to its permanent location, so at the moment, it has too much rake and the boom is riding lower than it should above the cabin. I'm thinking I'll get another foot of loft at the clew once I get the rake set properly.

    I've got four control lines coming off of the main mast that will get routed to the cockpit along the rails. Main halyard and topping lift will go stbd and tack reef 1 and tack reef 2 will go to port. The main boom will have outhaul, clew reef 1 and clew reef 2 at the aft end of the boom. The main outhaul will have a 3-1 tackle. The main sheet will have a 4-1 tackle to begin with, but may be reduced if found unnecessary.

    The mizzen will have all of the same lines, but they will all be routed forward and cleated on the mizzen mast. The mizzen outhaul will have a 2-1 tackle as will all of the reef lines.

    I've color coded the control lines for the most part. Sheets, halyards and topping lifts are white. Outhaul are black, reef 1 lines are blue and reef 2 lines are red. "REEF RED" may be a scary day.

    I'll say it again. Things are getting exciting launch day is getting close.
     

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  2. LP
    Joined: Jul 2005
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    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    I'm doing a myriad of small tasks that seem to take an inordinate amounts of time, but shows little progress. A lot of it revolves around planning and implementing the running rigging and also all of the ancillary items that go along with a sailboat. I've got the main pretty well set up. Still messing with the mizzen rig. No doubt there will be changes once the boat floats when reality introduces itself to design and planning.

    Currently though, I've managed to hoist the center board into it permanent home. For the most part it went relatively well. I only had to cut a little clearance in the boat structure and I also filled and redrilled the pivot hole in the board. Oh, and I had to build a scaffold off my front porch for the chain hoist. Here's a trio of pics for you.
     

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  3. latestarter
    Joined: Jul 2010
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    Location: N.W. England

    latestarter Senior Member

    This a major step forward as I recall the centreboard was the first thing you built.
    How do you plan to raise and lower it?
     
  4. LP
    Joined: Jul 2005
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    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    Hi LS,

    I've got a couple of ideas. The first was to use use a 3-1 black block and tackle, but a weight analysis of the board is making me think otherwise. The board weighs close to 200 lbs with about 25% at the pin and 75% at the hoist. This puts 150 lbs on the hoist which would mean a 50 lb pull to raise the board. Doable, but I think a little excessive. An uncontrolled drop could be a constant fear. So I'm leaning heavily (pun) towards a manual crank type winch that will offer drop protection and mechanical advantage. It would mount just inside the companionway over the board and should be easily accessed, but not too intrusive.
     
  5. LP
    Joined: Jul 2005
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    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    Progress notes:

    I've been working on the main mast step. I've designed it for some adjustment during during sea-trials should balance be off slightly. From the photo below you can see the shaped blocking. This is configured for a near vertical mast. Should I want or need some rack, I can reverse the positioning of these blocks. For more rake, I would make another set that allows the foot(heel?) of the mast to go to the fully forward. Once comfortable with positioning, I will install the blocking permanently.

    IMG_3433.JPG

    In this position, I was getting some interference between the mast and the forward bulkhead (lower portion of photo where white goes to black). The mast was slightly out of round there so I built a device to rectify this.

    A piece of plywood with the proper sized radius cut in it and a piece of sanding belt stapled in place.
    IMG_3444.JPG
    A handle added for leverage.
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    A reshaped mast.
    IMG_3434.JPG
    And finally; the belt to go with the suspenders. Additional clearance ground in the bulkhead.
    IMG_3431.JPG
     
  6. LP
    Joined: Jul 2005
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    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    I am finding that I really like sanding belts for more purposes than being used on my belt sander.

    1) It's about the only way to get an aggressive 36 grit sand paper today.
    2) Sized properly, they can be cut to fit your palm sander. Aggressive!
    3) Cut to about a 4" length, they roll up nicely for sanding fillets. Also, goose for aggressive spot sanding.
    4) Can be used for makeshift sanding drums.

    In this case, I wrapped a piece of belt around a hole saw and used it to finish the radius in the tool and to also grind the clearance in the bulkhead in the previous post.
    IMG_3439.JPG IMG_3442.JPG IMG_3443.JPG
     
  7. LP
    Joined: Jul 2005
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    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    Here are a couple of photos for you, Latestarter. They are the final design on the centerboard hoist. This is a $20 trailer winch I got from Harbor Freight. It's zinc plated steel and will need to be replaced eventually after exposure to saltwater. If I'm happy with the way it works, I'll install a stainless steel model at that time. To position it where I wanted, I had to cut a couple of inches off of the crank. Doing that, I also cut off the handle, so I made a different, knob type handle that doesn't intrude on the companionway quite so much.

    I do like the worm drive type winches as the worm gear is naturally braking. Also the winches I've seen of this type have the crank rotate in the horizontal plane and that doesn't fit well for me.
     

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    Last edited: Jan 16, 2019
  8. LP
    Joined: Jul 2005
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    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    "Hoist the main and sheet in the mizzen, Matey's." Or some other such non-such.

    Hoisted both sails at once! Looking for trouble spots with the running rigging. I don't think I boom drop off of the clew of the sail. I've mounted outhaul and reeling hardware on the upper side of the boom so any natural drop in increased by the mounting location. This is especially critical on the mains'l as cabin clearance could be a problem. Fortunately, I'm thinking I can simple flip the boom over and go from there. This lifts the boom by a couple of inches. I'm also not getting full full hoist on the main for several reasons. A too long shackle with a too big of a loop in the halyard coupled with a misplaced tack attachment are conspiring to keep my sail from lofty places. Best to figure this stuff out on dry land.

    I'm still sorting out cleating for the main halyard, topping lift and tack reef lines. I have tempory cleating, but want to improve it before posting. All lines do find there way into the cockpit.

    I did some simulated tacks and gybes with the main boom and found a tendency for the main sheet to foul when coming across the cabin. Moving the sheets from the end of the boom to a location forward of the aft end of the cabin appears to have solved this problem.

    The mizzen lines have been determined, but I need to get a few more pieces of hardware before getting it rigged. It's interesting though, I was having trouble designing the rigging on "paper", but working on the actual pieces presents quite different ideas. As a for instance, I was trying to run the controls up the boom, turn a corner onto the mast and clear with a downward type pull. In actuality, the outhaul and clew reef lines will go directly from the clew, follow the foot of the sail to the mast, hit a cheekblock and be cleated with an upward pull.

    I am really trying to avoid a boomkin, but my sheeting angles for the mizzen boom really $¥€£! None the less, we are going for the gusto with twin mizzen sheets that pull from each corner of the boat. Independent sheets turns the mizzen into a giant air rudder as you can over-sheet (?) past centerline. One sheet in each hand and it's like riding a horse....but backwards. Anyways, 3 to 1 sheets on each corner and we'll see what happens. I just don't know what to expect with regards to the wind loads the mizzen will received in the spoiled air of the main.

    IMG_3453.JPG
    Rigged for travel. I'm still working on this.
    IMG_3459.JPG IMG_3458.JPG
    And a bit of the inside.
    IMG_3446.JPG
     
  9. LP
    Joined: Jul 2005
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    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    Things are moving at a snails pace. I’ve got the running rigging pretty well set now. Some of the bits and bobbles won’t be permanently installed until after I see their performance in action. An extraordinary time has been spent on the masts transport jigs. In the last post, you saw them stowed, but the booms were only supported by their topping lifts. Not the best option for trucking down the highway. I’ve made a fixture for each boom that straddles the mast and secures the boom end without worry of chafe or damage. A second fixture supports the mast and boom mid span and supported by the rail.

    There are many small tasks that still need completing. That said, I’ve been working a “short list” of items that will enable me to launch her and that list has been completed. So, launch could be happening next week when I have some time off from work!

    I’m deciding whether to launch her fully rigged or to err on the side of caution and launch sans rig and do some stability checks prior to launching fully rigged. The latter will likely be the case with some gratuitous motoring on the kicker to get her out and get a feel for her motions.

    The main sheet. One of the design challenges was figuring a way to secure the pop top and I am quite satisfied with the solution. I’ll post it in a later post.
    40561060-2352-4FDB-9B53-F12E338554A3.jpeg

    The mizzen sheeting. Go ahead and say it. Ugh! I’ve debated the need for a boomkin and have decided to build one. I feel that I can launch and sail as it is, but I will be adding a boomkin for better sheeting angles. But, what I am going to do is take the opportunity to develope my carbon construction skills with it. I hope to eventually replace the engrire rig with carbon, but baby steps in the beginning.

    22734260-2509-4C54-A99C-06B0CC3503C4.jpeg

    Finally, one of the unfinished boom transport jigs mentioned. It uses outhaul and reef lines to secure everything.
    DEFFBF7F-C6A7-486A-9CC4-660C9B972F60.jpeg
     
  10. LP
    Joined: Jul 2005
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    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    Here a quick pictorial of my main hatch securing method.

    I have angled brackets at four strategic locations through bolted with backing plates. Here are two that coincide with my main sheet block location.

    1A3BE3DA-1D50-42F0-9BB4-7387C9602FAD.jpeg

    Each bracket has a strike plate that is screwed to the main cabin and bedded in 5200.

    9FDEDDF2-405E-4D35-B627-10202020C219.jpeg

    When closed, they are secured with bal-lok pins that load in shear. I will eventually place a fender washer under one of the bolts, bend up an edge, drill a hole there and connect a lanyard between it and the pin to keep them close when the top-hatch is open.

    A6953B29-3AF9-4771-8342-0CAEAF18CBCC.jpeg

    But, to the exciting part.

    SHE FLOATS RIGHTSIDE UP!

    1B5344C2-142E-40C6-9AC2-00389A788058.jpeg

    I chose to do the float test without the rig. She feels very stable. My weight on the rail may have given her a degree of heel. The inclinometer indicated less, but I’m not sure of the sensitivity of the device. I did a rocking test to determine the period of her roll. It was fairly quick and I wasn’t able to get an accurate measurement. It was a small and busy ramp so I was compelled to not spend too much time there. Ideally, the roll period (from one side to the other and back) should be the waterline beam, in feet, divided by 3.28. At 7.5 feet, that would come to a roll period of about 2 seconds. My guesstimate put it at 1.0-1.5 seconds. I anticipate a slower period with the rig up. A faster period is a more stable boat and possibly too stable for comfort and a slower period is a less stable.

    We took her out with the kicker motor to get a feel her her sea legs. I think the rig will dampen some of her roll. A couple of the bigger boat wake had her rocking pretty good. I dont have a method for keeping the rudder down, yet other bolt tension. I’ve got a plan for it. During the first float , the rudder would pivot up cause a significant amount of drag so I may have to modify it slightly for shallow operations to minimize drag. I am also considering shortening the rudder, but will wait until after some sailing sea-trials.

    On the confessional side, we had to float the boat twice to get it out in open water. I misinterpreted some pictigram on the fairly new to me motor. Motors could run very well if you don’t turn the gas on. A busy boat ramp is not a good place to be troubleshooting engine issues, so in the comfort of my driveway, I started working through the fuel system and reading pictographs at a leasurely pace. A big “DOH” to me. Oh well.

    More to come.
     
  11. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Somehow I missed this thread-what a great job you have done. Most impressive!!
     
  12. LP
    Joined: Jul 2005
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    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    First sail: Complete!

    The first sailing trials went well....for the most part. We put in at Monroe Canal Marina in St. James City, FL. It's fairly protected and less public than the public ramps in the area so embarrassing moments are shared by fewer people. o_O Anyway, hoisting and rigging took about an hour as most lines had been unrigged for some mast work. I'm hoping to cut rigging time in half once we get more proficient at it.

    We put in and docked on the windward side of the ramp with the centerboard up. When the dock lines were let loose, the windage from the main mast really set the bow adrift....in the wrong direction. Setting the board and strong, judicious of power got us making way and regaining control of the vessel. The motor out was uneventful and upon reaching the channel we were set up for a beam reach with the prevailing winds. Erring to caution, the mizzen was set to a double reef and then the main was also set to a double reef. The motor was set to idle, control was confirmed so the engine was turned off. We were sailing! I feel like we had 10-12 kts on the beam and we were doing 3-4 kts with the double reef and just a couple of degrees of heel. Getting out to open water meant going directly into the wind so when the time came, we relit the engine and motored out until we could catch the wind again.

    There were several goals associated with this sea trial.

    1) Do I need a downhaul/cunningham on the main?

    2) Do my modifications to the rudder work?

    3) Does the boat stand up well to a good press of sail?

    4) Is the sheeting angle on the mizzen workable or is a boomkin needed?

    5) How does the control line configuration work?

    Back to the trials. In open water, we set up between a close reach and a beam reach, just looking to get a decent turn of speed and feel the boats responses. The double reef was working well with little heeling so a reef was shaken out of both sails. The boat responded well to the increase in power and heeling was still in the 5-10 degree range. Comfortable in this configuration and feeling a little bit of weather helm, the full main was let fly while keeping the mizzen to a single reef. At this time the wind had picked up a bit more and we might have been seeing 15 kts. This worked quite well. We were heeled about 15 degrees and we worked this configuration through several tacks. This is when things fell apart, literally.

    And I'll get back to that, but first my findings.

    1) A downhaul (or a halyard winch, but I'm avoiding winches at this point) WILL be beneficial to luff tension and sail shape.

    2) Yes and No. On the first outing under motor only, I had not determined a means for keeping the retractable rudder extended and relied solely on pivot bolt compression to lock the rudder down. This only provided marginally acceptable results. This time, I mount 1/2" shock cord to the forward side of the rudder, routed it over the top and to a cam cleat on the back of the rudder head. This worked, but the stretch on the shock cord caused a significant reduction in it's diameter and it eventually pulled from the hole it was epoxied into putting us back square one on the rudder issue.

    3) Yes. The boat stands up very well and I am very excited by this look forward to more trials.

    4) The sheeting angle is not good on the mizzen and a boomkin will be added to the rig. I was surprised at the load on the mizzen sheet, but also encouraged by the power the mizzen must be producing.

    5) For the most part, pretty good. The mizzen halyard and topping lift cleats need repositioned for better accessibility.

    As for falling apart, when the rudder downhaul let go, the rudder went horizontal. In this position, it produces exceptional drag and it places a extreme loads on the tiller. One thing led to another and Murphy jumped onboard in no time. I had designed a hinge in my tiller and I had not tightened the nut on the hinge bolt because I was going to disassemble the tiller for varnish. With the extreme loads from the rudder and no clamping force from the hinge screw, the tiller was starting to split from the lever action from the tiller handle.

    At this point we were effectively disabled about half a mile to a mile off shore. BUT, the wind was blowing up back to shore and we still had a motor. We started the motor, pointed into the wind and made way to keep the forces from going to the tiller handle. First issue was to save the tiller. Tightening the nut on the screw put proper force transmission back into the tiller. That complete, We turned our attention to the rudder. The pivot bolt was not torqued down so the rudder would be free to pivot with the downhaul control. Having lost that ability, we needed to torque the pivot bolt tight so compression would hold the rudder in the down position. I rigged a bosun's chair from the main sheet, secured it to the mizzen mast and dangled myself half in the water off the stern of the boat. Yes, I turn the motor off. Then my wife hung over the transom with my daughter holding her feet and she held a wrench to the bolt while in cranked on the nut with a ratchet.

    Having restored control to the boat, we rehoisted the sails and had a leisurely downwind sail back towards home. There might have been a swig or two of rum taken after our little bit of folly out on the blue. Even though we had some struggles, I think the first sail was a success and we gain valuable insight into how the boat will perform and also what needs to be corrected and improved to turn it into a reliable cruiser.

    I have already modified the rudder in two ways. I have cut 6-8" off of it's length so I can fully extend it while at the ramp and I have added a bolt hole so that the rudder can be bolted in the down position. If I have lost rudder authority with the shortened rudder, I am prepared to build another with additional area, but at the same depth as it's been shortened to. I am not giving up on the retractable rudder, yet. I will replace the shock cord downhaul with some 1/2" yacht braid. Since the yacht braid won't stretch (and shrink) like the shock cord, I feel it's attachment will be much more dependable. There is an area on the rudder where the rudderhead and the rudder blade meet that is grossly unfair. I am adding a fairing block there to clean that up.

    I have also started making a plug for the motor well to fair that out. My plans are to have a fairly close fit with seals where possible and to add a suction plate underneath to try to pull water out of the well. Lastly, I left the bottom (forward when extended) edge of the centerboard square on the chance that I might cast a lead shoe to mount there. For now, I plan to build a shaped leading edge to go there for improved flow over the centerboard. Currently, all ballast is internal and she stands up great with it there.

    Ready for launch.

    D7F50162-F113-4842-82AF-FEE6E098D3CC.jpeg

    Underway.

    D5DE962C-6C75-4EBE-9A81-D3E068046B83.png E1555F4C-79F3-4586-B939-7361E37F3445.png

    These two are from a video that I may get uploaded once I do the learning curve on videos.
     
    Last edited: May 12, 2019
  13. LP
    Joined: Jul 2005
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    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman


    Thanks for the kind words, Doug.
     

  14. LP
    Joined: Jul 2005
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    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    Some goings on. My laundry list tasks before launching again is going to take a while. The rudder got chopped. More for launch and retrieval that for operation reasons.

    E32F04A9-6AD4-41AD-9210-677079145146.jpeg

    I’m toying with an entirely different rudder, but we’ll see how the shorter rudder works. I shortened it so it could be fully extended for launch while still on the trailer.

    Additional appendages:

    5045E9AE-F861-486C-9FCC-CC8783DF6FC5.jpeg

    In the foreground is an extension to the centerboard. Originally, I had lead shoes on the bottom of the centerboard and hull. The difference in righting moment was so small between bottom mounted ballast and internal ballast that I opted for internal ballast. The shoes were part of my lateral area calculations so I’m adding a centerboard extension to replace the lateral area of the lead shoes.

    The new boomkin is in the background.

    A hole in the transom for the boomkin and the internal structure for mounting the boomkin.

    599C3FF5-90AA-470B-81F1-777B8F063215.jpeg C0EAF5F7-DB33-4894-816A-B1C8FFDC8C22.jpeg

    The boomkin is designed to be retracted into the cockpit for convenience. Mizzen control will be greatly improved and simplified with the new boomkin.
     
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