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

    Awwwww, Scuppers!

    Just an excuse to post a picture.

    GOPR0229.jpg

    The port cabin side went on without a hitch. Lots of goop and screws. Putting on the big pieces really gets the excitement going. I've shaped the monolithic piece I had saved for the aft coaming into something more attractive and functional. I'll save the picture until it's really installed. The decks are now all laminated and I've gone in and added the scuppers to the toe rails. Six per side. Maybe overkill, but holes are cheap I was able to do this without any difficulties as all fastener locations were marked and scupper locations were laid out accordingly.

    I've also laminated the aft coaming and forward cabin panels with 6 oz. cloth.

    The next few days should see significant structure additions. :cool:
     
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  2. gbennett1987
    Joined: Mar 2016
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    Location: Grand Island NY

    gbennett1987 Junior Member

    Late coming into this LP. My wife and I think the hull plank job you did looks really beautiful !

    Looking forward to seeing how you progress as I get supplies lined up to start mine once the warmer weather is settled in. Can't afford to heat my garage so need warmer weather before I can use epoxy so can't really start much yet since I wouldn't be able to encase the wood.
     
  3. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Instead of heating the garage, heat the local space you'll epoxy. I use those oil filled heaters you can get at Wal-Mart for $20 bucks. Toss a tarp or a blanket over the thing you're epoxying, of course propping it up so it doesn't become part of the work and stick a heater under it. In freezing cold, you can maintain over 70, which will kick off most regular epoxies. I also have used foam insulation board, like the kind used on HVAC ducts. These work really well and keep in the heat. I have several panels and can rig up a 5 sided box on a bench or floor to cook or post cure some goo.
     
  4. LP
    Joined: Jul 2005
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    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    Upper Structure Tour

    I've been getting a lot of pieces installed over the few days. Some pieces have been cut for a while and others are freshly cut. Some are both.

    The forward deck house bulkhead. There is the temptation to double up the corner structure with a triax wrap around the corner post. The way these posts are cut, there is plenty of faying surface for the epoxy to work on. Those are 3/8" x 5" SS lags in the bottoms of the corner posts.

    GOPR0246.jpg

    Forward side V-berth bulkhead. The panels are simply butted together and glued. The vertical members are shear ties to carry loads down to the lower panels that solidly attached to the hull. I decided to enlarge the V-berth access for multiple reasons. I was originally smaller for more privacy, but practicality prevails. Better access means less chance of disturbing my better half when getting in and out. I can now sit in the V-berth, put both feet on the floor and brew coffee without getting completely out of the berth. This bulkhead is crazy heavy. 3/4" Meranti. A bigger hole equals less weight. Doing it again, I would go with a thinner panel here. The upper segment is Okoume.

    GOPR0247.jpg

    V-berth bulkhead looking forward. Galley will be to the left. I plan to cut handle above the V-berth access for easier entry.

    GOPR0249.jpg

    Companionway, aft cabin bulkheads, etc. The step is a little so I need to lower it some. I believe I can get away with the single step. I notched out the lower companionway opening finally. It's been a real shin knocker up until now. This area is still fairly fluid and will see changes before being called complete. For now, I've simply left the companionway sides vertical. I'm still deciding on the actual positioning and width.

    GOPR0248.jpg

    Companionway from the cockpit. I mis-installed the right hand side and had to cut it loose from the cabin side. I also had to cut through 2/3's of the bottom joint so I could hinge it out 1/2" to get it in it's proper position. Measure twice, glue once, right?:rolleyes: All fixed now.

    GOPR0251.jpg

    Finally, the aft cockpit coaming. The notch is where the mizzen steps and is the first guide in stepping that mast. I almost feel that I need to trim the side coaming down about an inch. I'm not eager to do this though as I really like the way the cockpit feels as I sit in it. It's very comfortable and supports you in all of the right places.

    GOPR0250.JPG

    That's it for now. I've glued in some more support pieces and applied FG tapes to finish out the structures in the photos. I'm looking at installing the centerboard before moving on to the cabin top.
     
  5. LP
    Joined: Jul 2005
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    LP Flying Boatman

    I've been pondering the design cabin top almost full time now. I will be committing to a choice pretty shortly. Working on your own design means that the design committee is constantly in session. If I was building someone else's design, I might be less inclined to deviate from the plans.

    The latest round of thoughts was spurred by my wife as I was giving her a tour of the latest developments on the boat. Something was said about a hatch over our heads in the V-berth area so we could see the stars at night. Moving the forward deck hatch to the cabin top over the v-berth has some merit. Getting up through the planned deck hatch would involve some minor contortionism, but would put you right where the action is. Putting the hatch in the cabin roof would move you away from the action some, but most things are still within reach. The bonuses are no contortionism and a drier location to work from. If also clears what little forward deck space I have of a major obstruction. I'm pretty set on the positive nature of this change.

    The longest debate has been over cabin height. I've considered pushing it all of the way to 6'. If I did this, I would forego any companionway hatch and simply go with access through the aft cabin bulkhead. Maybe, put in a 1 to 1 1/2 foot flip hatch on the cabin top. The simplicity and strength of this design has a lot of merit. The down side is windage and appearance. I'm not even sure windage would increase as the cabin roof would be a simple high arch with no obstructions, I think. As much as I would like to have standing headroom, I don't think this the way to go about it on this design. There is no point in pushing the roof to "close to" six foot because you suffer all of the disadvantages of a higher roof without the any of the advantages.

    To digress for a moment, by adding a hatch over the V-berth, I am left with changes to the current plan for the companionway hatch. The original plan was to have a telescoping hatch that would open up the entire saloon area to unlimited headroom. In fair weather anyways. However, when open these hatches would have to live over the V-berth portion of the cabin roof. Thus, the dilemma. The fix this, I was willing to not have a companionway hatch and place a second hatch over the galley area as that would be the most likely place to have a need for constant standing. Again, maybe a short flip hatch could be employed at the companionway.

    The last idea I have is to go with a lower coach roof and install a pop-top type hatch design that runs the length of the saloon and is about two foot wide. It would be dressed out with fabric, tent type material with zippered windows and bug screen. I feel that this may be the best option for me as it keeps the roofline low for wind, CG and appearance reasons and has the added bonus of full standing headroom while at anchor. Ventilation and bug protection are a couple of other benefits. During fair weather and mild conditions, I could see propping up the aft end of the top for better air circulation while under way. I only need to work out the details of the lift mechanism.

    I've fished out my centerboard from it's hidey-hole and started prepping it for installation. I've decided to call it "The Motherboard" because it is one mother of a board. It's close to 200lbs without any lead! I've trimmed it's lower edge to the profile of the bottom of the hull. I'm leaving the lower edge square so that I can eventually place a lead shoe there. For now though, I've lined the lower surface several layers of fiberglass for impact and abrasion resistance. Casting my ballast will be one of the last things that I do. Initial sail trial will probably take place with secured internal ballast. The change in CG between inside the hull and mounted to the bottom of the hull is almost negligible. A shoe on the centerboard has more effect on the CG since it can be lowered a greater amount. In the interim, I question whether The Motherboard needs any ballast at all because of the massive amount of SYP in it. I'm really pushing myself to at least put 50 lbs. inside the board. In this configuration, I believe that a four part tackle would be adequate. A lead shoe will mean using a braking winch or a worm drive winch.

    Off to build some more,
     
  6. LP
    Joined: Jul 2005
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    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    Flying by the seat of my pants.

    Or something like that. The coach roof is proving to be more of a challenge than planned. Of course, I can't seem to do things the easy way either. The first plan of action was to lay out the roof line in profile. I took a long batten and laid it across the top existing structure and put an adjustable batten athwartship at the companionway opening. A couple of heavy bar clamps were put on the ends of the batten to weight it properly to get the roof curve I desired. With this set, I could take actual measurements and determine radii at various stations along the cabin for supplemental support structures; temporary and permanent.

    My plan A was to epoxy some 5/8" x 1 1/2" battens to coach roof panels and as these panels were bent into place, the battens would force a secondary curvature into the panel for my desired roof shape. I have done some experimenting with this technique and had some success with it. I'm afraid that I departed from my experimental successes too far and ended up with unacceptable results. The panels did compound some, but formed ridges at the batten locations. When epoxying the battens on, I drilled a hole every foot and used temporary screws to hold the battens until the glue set. At each screw hole, I also got minor crushing of the batten that could have gone catastrophic if more bend had been put in.

    Time to step back and punt. Plan B has me running the roof panels longitudinally and I am framing out the pop-top/companionway hatch and will not roof over that portion of the cabin. Plan A was to roof it all and cut the opening later. Plan B does not. With the results from plan A it makes sense to keep the panel sizes to a minimum so that internal panel stresses are kept to a minimum. Plan B also is more aligned with my previous compounded panel bending experiments. I'm optimistic that plan B will work.

    Plan C, should I need it, will most like be a redesign of the coachroof to be more conical.

    Today I started framing out the opening in the coach roof. My Companionway is offset by about 2" due to my centerboard box being offset. I was going to continue this thought process in making the pop-top, but after framing in the opening, I believe the popper should be centered on the cabin. Another back up and punt. It reduces the complication of the pop-top, decreases panel size on the SB to that of Port, and gives more room to pass in the cabin when the top is up. So it's all good. Going wider with the pop-top will most likely not let me decide to go with a sliding hatch later as the popper is going to be around 30" wide. Too wide for a hatch, I believe.
     

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  7. Jamie Kennedy
    Joined: Jun 2015
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    Location: Saint John New Brunswick

    Jamie Kennedy Senior Member

  8. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Diagonal plank it or strip plank it (the compound roof).
     
  9. LP
    Joined: Jul 2005
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    LP Flying Boatman

    Thanks.
     
  10. LP
    Joined: Jul 2005
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    LP Flying Boatman

    Plan C (alternate).

    Strip planking is on the back burner. I have the ply and would like for it to work. I'll know in a couple of days if its going to.
     
  11. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    I'm not sure of your scantlings for the roof or your intention for it's construction, but a couple of alternating layers of 1/8" plywood, say at about a 30 degree angle to the centerline, looks like it'll accommodate that curve. Of course, it'll need to be faired and painted.

    A severe compound deck I did a few years ago gave me a fit, so I strip planked it. The client wanted a laid deck, but it was so crowned, nothing would edge set to those curves, unless they were square stock. So, I bent square stock, 1.5" to one side only. I glued two strips to each other, skipped a glue line then two more strips, until the deck was covered. Then I removed each 2 strip combination and ran them through the table saw, knocking them into 2 sets of 2 strips, about 5/8" thick, which were then planed down to about 7/16". Now I had book matched strips, that I could flip for the other side, set to the appropriate curves for the deck. It was a pain in the butt, though worked well with the cypress and the contrasting colors in it.

    You can go foam too. Yeah, it's not pretty under varnish, but it's light and stiff if you have enough fabric. A cool way to do this would be to bend the foam, maybe diagonally to make the curves, with a fairly light sheathing, then rip 2.5" strips of 1/8" or 1/4" plywood, for longitudinal planking on the inside and out.
     
  12. LP
    Joined: Jul 2005
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    LP Flying Boatman

    Still trying see if plan B is going to work.

    Quick question on an unrelated matter.

    What is a good size for a forward deck hatch? (Is there a standard? Just big enough to fit shoulders through? Personal preference?)
     
  13. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    24" is a big hatch, 18" is about average and most can't get through much less than 15". Cut a hole in some cardboard and see what minimum you can climb through, then make the hatch 1" bigger all around.

    About plan B, this is the way I usually do it, but I often cut out the companionway opening after it's skinned to the carlins and other framing. This lets me get fair curves, when bending stock over the framework. I also can't see how you'll get any material to "lay down" without some form of molding or strip planking. There's a lot of shape there to accommodate.
     
  14. LP
    Joined: Jul 2005
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    LP Flying Boatman

    An 18" hatch should work. I'll do the cardboard trick and see what I come up with.

    Here is a shot of the forward roof panel and the port panel.

    GOPR0279.jpg

    Note that the forward panel is laid athwartshaip and the port panel is for n aft.....and still uncut. I spent a fair amount of time today framing in some 2 x 4's to support and shape the roof panels. Two over the saloon area that frame the pop-top area and two in the V-berth area that will frame the forward hatch. These were meant to be temporary supports, but may be trimmed back severely and made into permanent structure. The fore panel has no battens, but with the additional supports has taken an acceptable shape. The side roof panel seems to be taking the shape well and laying like I want it to. The only real questionable area will be the joint between the panels. I plan to use a butt block on the under side, use a lot of goop and some very discretionary clamping to make the top side fair.

    Tomorrow, I hope to do the final fit on the port side roof panel and run the perimeter screws to see how it all pulls down and pulls together. Note the 2x4 on the inboard edge of the panel. Bar clamps spread along it's length really distributes the clamping forces and fairs that edge. If I'm comfortable with the outboard edge shape after screw down, I will leave the panel uncut until after glued and set. The extra panel width provides for a a lot of leverage when pulling that edge into place.

    Paul, I'm not sure I understand your "molding" reference. I am planning a piece for the exterior perimeter of the roof. Is this your molding? I was going add it after trimming the roof ply to the cabin sides. Perhaps, It is better to add the perimeter molding(?) first to broaden the gluing footprint on the roof panels?:?: I have a piece on the inside already.
     

  15. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Never mind. If you can get it to bend, you don't need my advice. I was thinking to make the compound, you'd need to diagonally bend some thin stuff, but hey, you look to have it, so what do I know.
     
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