Blackrock 24 (Build)

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

  1. LP
    Joined: Jul 2005
    Posts: 1,404
    Likes: 56, Points: 58, Legacy Rep: 584
    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    I'd rather be lucky than good. :D
     
  2. LP
    Joined: Jul 2005
    Posts: 1,404
    Likes: 56, Points: 58, Legacy Rep: 584
    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    It appears that I'm not out of the woods yet. I noticed some slight flat spotting behind the panel joint after screwing down some alignment blocks. I'll mess with it some more in a few days. I'm on a lumber run to the Boston area for some vertical grained Douglas fir for my masts.
     
  3. SukiSolo
    Joined: Dec 2012
    Posts: 1,270
    Likes: 25, Points: 0, Legacy Rep: 271
    Location: Hampshire UK

    SukiSolo Senior Member

    The deck and cabin coming togeter nicely LP. Yup, some ply seems to bend less than evenly, it's very sheet dependent (ie core veneers) and often I've had to test several sheets to find one that gives an even bend. Of course the more you curve it, the more any uneveness shows up...;)
    Sometimes it even pays to make the ply ie cold mould veneers semi in situ with a poly sheet underneath to take the glue squeeze out etc. Still you seem to have sorted it well. Might be worth pull/pushing any flat spots out with temporary bracing and maybe a little heat.

    Keep up the good work, she'll be floating this year.

    I understand some guys are cutting a near 100' Doug Fir local to me, but your closer to it's native origin...
     
  4. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 471, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    I've used both heat and a floor steamer to get plywood to comply at times.

    Site's back up . . .
     
  5. LP
    Joined: Jul 2005
    Posts: 1,404
    Likes: 56, Points: 58, Legacy Rep: 584
    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    A view from the inside.

    To back up a little bit. Here is a photo of my roof panel preparations. The 1 1/2" x 1/2" battens are epoxied in place with some reverse curvature. In this case, the battens are evenly spaced on the panel in planning to lay the panel athwartship. By placing some reverse curve to the panel during glue up, even with the panel flat, the battens will try to put some compound curvature into the panel. In the original placement, the reverse curve was probably not necessary. The wide angle lens makes the photo look a little wonky (Sorry, too much Harry Potter with the daughter), but it gives an idea of what I'm doing.

    GOPR0256.jpg

    The problem now is that the batten runs off to the side of the panel in it's new orientation. The plan is to put on a different batten in the forward portions of the panel closer to the centerline of the panel to see if I can coax the flat spot out that is forming there. The panel is much flatter longitudinally in this orientation so putting reverse curve in during glue up is desirable. I may use doug fir instead of the weaker S or P that I used earlier. And then whether to remove the offset batten........decisions....decisions....:rolleyes: Anyways, cross fingers

    GOPR0276.jpg

    Suki, Thanks for your optimism. Between building masts and other appendages, ballast, trailer set up, ordering sails and all of the other multitudes of minutia that is requires to get a boat afloat, I'm afraid I'll run out of summer before I get there. Fingers crossed (again). Sea trials in Florida. Now there is an idea.

    Paul, Good to here your site is back up. I actually employed my kerosene heater on the forward cabin top. I put it up in the v-berth area and wet down the roof panel. The panel went on ok without the heat and moisture. I was looking more to relax it once it was in place.
     
  6. LP
    Joined: Jul 2005
    Posts: 1,404
    Likes: 56, Points: 58, Legacy Rep: 584
    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    3 steps forward and 2 steps back.

    That's what it feels like sometimes. Of course, when you are reinventing the wheel, there are bound to be setbacks. :mad: Nothing major other than putting on a roof panel, taking off a roof panel, putting on a roof panel, taking off a roof panel.......you get the picture. I was almost ready to go to plan C yesterday, but I think I've got the roof dialed in finally.

    I rough trimmed the port roof panel to size yesterday. I was hesitant to do so as the excess material gives a lot of leverage and also induces desirable curvature when bent into place. Good reasons to trim the panel once glued in place. Leaving the excess on places more internal stresses in the panel to resist any compound curvature that might get placed in the panel. And to that end, I chose to remove most of the excess material. That is where I almost threw in the towel on the current plan. I ended up with a couple of flat spots instead of the single one I had before.

    The last ditch effort: I pulled some old shirts from the rag bag, wet them down and threw them on the flat spots, pulled out the kerosene heater and draped the whole cabin with a plastic sheet and applied outward pressure to the flat spots. I baby-sat the whole mess for a couple of hours while the heater was running then left it to set over night. This morning I pulled the cover and the shirts off. I found shapes I could live with so now life goes on. The flat spots may come back if I pull the supports, but I feel reasonable comfortable that I can maintain the desired shape with proper force during glue-up, followed by laminated in place sub-frames in strategic locations.

    I am hoping now to actually start some permanent installation of the roof panel. :D
     
  7. LP
    Joined: Jul 2005
    Posts: 1,404
    Likes: 56, Points: 58, Legacy Rep: 584
    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    I love the smell of cut douglas fir in the morning.

    Screwed the pooch on my pop-top carlin/coaming units. It feels that way anyways. There was most likely no ways to avoid to avoid some of my results, though one side was much worse than the other. To make things more clear, I have a couple of longitudinal carlins cut from 2x4's that are 2" deep, 1 1/2" wide with a generous chamfer on the lower, outboard edge. Mating to the inboard side is a 1x4" piece of doug fir that forms the coaming for the pop-top.

    I chose to install the roof panels in two steps. The inboard edge was glued to the upper edge of the 2x4(shaped to cabin profile) stock. When cured, the outer edge of the roof panel was pulled down and glued to the cabin edge and structure. The reason for doing this way was to attempt to lock the inner edge into position and induce proper curvature of the panel. The roof radius is as sharp as 50" in 3/8" stock. Between me being casual with the carlin/coaming glue up and torsion from driving the roof panel down, I ended up with quite a bit of flair in the port coaming. The starboard coaming fared much better and if the portside had turned out the same as the starboard, I think I could have lived with them. I could not live with the portside results. I ended up truing up the lower edges and added a cap strip (edge nailed and true to the lower edge) to give adequate stock for a consistent 1 1/2" lip on the coaming. I'll go back and fill between the "trued" edges with thickened epoxy to bring it all together. I had hoped to bright finish these coamings, but will probably paint them now.

    All-in-all, the cabin roof has finally come together in an acceptable fashion. If I were to design it again, I would put more focus on determining a developable shape. In the process, I've devised a couple ways to create a conic that appears compound. Also, I'd not try to bend a single layer of ply so severely. There is a definite tendency for thicker ply to resist bending and create flat spots. Live, build and learn.

    I've planned to relocate my forward hatch from the foredeck to the forward cabin roof. Anchoring may now require me to get out on the foredeck, but I believe I can still do all sail work from the security of the hatch and possibly in a much drier place. That being said, I find myself in a position of reluctance when it comes to actually cutting the opening for the hatch in the forward cabin roof. The challenges of the roof install make me not want to cut a big hole it in. :( Due to the amount of curvature in the roof and to keep hatch construction simple, I've designed a semi-recessed hatch design. The outboard hatch coaming edges will have about 1 1/5" rise and the athwartship pieces will be cut straight and will need a channel for the fore and aft hatch edges to fit into. This will help keep the hatch profiles low. I hope I'm not asking for water ingress with this hatch design. :eek:

    Here are a couple photos.

    GOPR0287.JPG GOPR0289.jpg

    And a couple of artsy, photoshoped images just for fun.

    Pencil.jpg Antique.jpg
     
  8. SukiSolo
    Joined: Dec 2012
    Posts: 1,270
    Likes: 25, Points: 0, Legacy Rep: 271
    Location: Hampshire UK

    SukiSolo Senior Member

    The fun bit eh?. I'd agree it's easier to bend the thinner stuff and exactly how much from a true conic is pretty critical. You can get some but you need to know when to give in too. Also rather than just accepting the ply won't go into the desired shape you can always slit it (locally to get the curve), and reglue, and then put a capping single veneer on top which will most times take the curvature.

    Nice work LP. Good to see her coming on.
     
  9. LP
    Joined: Jul 2005
    Posts: 1,404
    Likes: 56, Points: 58, Legacy Rep: 584
    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    Details, details, details.

    The work continues. Here are a few pics of the details.

    The inside corner at the confluence of the cabin side, roof, coaming and aft cabin. A doubler was added to give some thickness for a radiused edge. The cabin top nailer is also joining the fray. Everything was given a nice sculpting. The doubled area also adds the illusion of a longer cabin when viewed from the outside.

    GOPR0298.JPG

    Outside in the same area. Doublers were added to the outside coaming edge to strengthen the area and to, again, put on a nice radius. This also makes a good delineation between painted and varnished areas.

    GOPR0297.JPG

    The coaming ends. A continuation of the doubled area. Note the use of solid wood in the straight areas of the coaming and ply use in the more curves areas. Paint will hide these inconsistencies. I think I will add a little more radius to the upper, aft corner. Let's not forget the limber. (Or, is it a scupper since it drains outside the ship?)

    GOPR0296.JPG
     
  10. LP
    Joined: Jul 2005
    Posts: 1,404
    Likes: 56, Points: 58, Legacy Rep: 584
    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    Hatchlings and Bumpkins

    My once smooth(ish) cabin roof is covered with bumps and grooves and ridges and covers. These pics where taken at the same time as my previous post. I've been too lazy to post anything.

    Pop-top hinge bump.

    GOPR0306.JPG

    Forward hatch hinge bump

    GOPR0312.JPG

    Grooved recess for forward hatch. Allows for a lower profile. The pop-top has a similar grooved recess.

    GOPR0311.JPG

    The rail. One mode for going forward is over the coach roof. Call it a roof toerail. There will be a textured path inboard of the rail and outboard over the bump.

    GOPR0313.jpg

    Companionway hatches open.

    GOPR0305.JPG

    Companionway hatches closed. I've opted to hinge all of the components instead of using drop boards. I'm not sure if these hinges are stout enough. I would be open to input.

    Because the companionway is slightly offset, I've split the doors so that when they are open, they extend to roughly the same buttline on either side of the boat.

    GOPR0302.JPG

    A view looking forward in the cabin.

    GOPR0314.JPG

    A view looking aft in the cabin.

    GOPR0315.jpg

    A need to take some more photos to show current progress. Mostly, I've been filling and fairing my bumpkins and hatchlings. I've done some work with the forward mast step and chain locker. These will be in the next post. Almost all hull construction is done now and most work is in surface preparation for paint. Woo! Woo!
     
  11. LP
    Joined: Jul 2005
    Posts: 1,404
    Likes: 56, Points: 58, Legacy Rep: 584
    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    Filling, Fairing, sanding, filling, fairing, sanding, filling, fairing, sanding.........

    It's and endless cycle that feels like it will never end. I do continue to make progress. The coach roof is to the point where it only needs a final sand of 120 grit before primer can be applied. It's the little details that take the time. I've had to make clearance cuts for the lift struts and cutouts for their mounting pads and then recoat and sand those locations. The idea is to avoid disturbing the finishes once they are applied.

    The cabin sides are ready for their final sanding at 120 grit. I may go to 220 since the cabin sides get a bright finish and I usually do 320 grit between finish coats.

    The decks are ready (mostly) for their final coat of epoxy. some minor filling is still required around the chain locker and forward and also at the aft cockpit coaming.

    I'm also working the cockpit will fillers now to get it ready for finishing. I'm getting eager to switch to paint and varnish, so I'll have to keep the the horses in check to not get ahead of the game. I am ready to go pick up my aux motor. I'm toying with getting a short shaft kicker so it can fit as low down in the motor bay as possible and maybe have a lifting transom so it can be pulled clear of the water when under way.

    So on the the pictorial section.

    One of my design goals is to be able to step the masts single handedly. To assist with that goal, I've added structure in the bow area to provide lateral support during stepping.

    First pic looking down: Guide rails that keep the heel of the mast on the stem as the it rides down the stem towards the step. Above that are a couple of psuedo-guides that also function to keep anchoring hardware clear of the mast. All of the areas that I expect to be a sliding surface have been coated with graphite filled epoxy. Graphite make epoxy very black.

    Second pic is more of the same. The guide rails were made from the laminated roof beams that I ended up not using.

    GOPR0320.jpg GOPR0321.jpg

    Stepping the mast.

    GOPR0322.JPG GOPR0323.jpg

    Mast stepped and view of chain locker.

    GOPR0325.jpg

    View aft of cabin roof.

    GOPR0326.JPG
     
  12. LP
    Joined: Jul 2005
    Posts: 1,404
    Likes: 56, Points: 58, Legacy Rep: 584
    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    Mixing mystery (solved)

    I've been dealing with a mixing mystery for the last couple of years. I mix by weight and I am always long on resin when I start running low on my stock. In an attempt to use my supplies evenly, I started adding an extra 1/10th oz for every oz. of hardener used. (2 oz hardener means 4.2 oz. resin). Even with this correction, I was still running long on resin. I received a new batch of epoxy this weekend so I took a gallon each of resin and hardener and weighed each one. Shock of shocks. The hardener came in at 8 lbs while the resin came in at a whopping 9.4 lbs. This is a serious disparity to not be aware of. Oz. for oz, volume wise, the resin is 1.175 oz. the the hardener's 1.0 oz. or roughly 17% heavier. I don't believe I've erred with any of my calculations here. 2 to 1 by volume is going to 2.35 to 1.0 weigh wise. This is serious *#%?. :eek:

    If anybody sees this differently, let me know. :confused: Due to my constant excess of resin, I believe I've got this right. :(
     
  13. LP
    Joined: Jul 2005
    Posts: 1,404
    Likes: 56, Points: 58, Legacy Rep: 584
    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    Time to catch up.

    I've been pretty busy concentrating on getting the exterior finished. In other words, I've been doing a lot of sanding and filling and sanding and filling. I mind numbing experience on the topsides of a 24' sailboat. :( Not much worthy of putting pictures up about. There is also the multitude of other little side tasks that need to be completed before the sanding and filling can be completed. Ugh.

    As the boat stands now, the cabin top is primered, cabin sides have four coats of varnish and the decks have been primered. The cockpit is still bare epoxy as there are a few more tasks to be completed there. The pop-top is primered outside and painter and varnished inside. All of the hatches and access doors are constructed and being propped for paint.

    A note on primer. I had some cheap nappy rollers that I chose to use use for the first coat of primer thinking that I need to sand it anyways so a few stray strands of nap aren't a big deal. Better rethink that. The second coat was put on with a fine foam roller and a lightly thinned primer. An amazing difference in pre-sanding finish. Throw out the nappies! It's amazing how much work can be saved by choosing the proper process.

    I've also made some acquisitions. A road trip to Michigan netted me 960 lbs. of lead ingots for ballast. Another smaller trip brought me a fairly new aluminum trailer. It's rated for twice the capacity of my boat so I hope I don't regret getting too much trailer. It's nice though. Twin axles, aluminum wheels and four wheel disc brakes. I though I was getting a little kicker motor, but the guy flaked out on me so I'm still in the market for one. I'm standing by on completing my motor well until I have a physical motor to work with in finalizing the details.

    A funny thing happened on the way to the sail makers. :D Well, not really. More like a funny thing happened with my Freeship file, but I don't feel that's much of an attention getter. :(I do my preliminary sailplan design work in Freeship and take that data and manipulate it elsewhere. Over the course of the build, I have switched to a new computer and and sort of lost track of the latest and greatest Freeship file I was using for that purpose and ended up using an older file. :eek: So in comes the new boat trailer that has bunks for a power cruiser. Now I'm looking at my Freeship file to pull off hull data to design the new bunks for the trailer when I start seeing some funkiness between the file and the boat thats sitting in my shop being built. Out come all of the Freeship files and off I go questing for valid data. I find the proper file and fortunately, nothing is amiss in the my build. I had an eleventh hour hull reshaping when I discovered my 8' garage door wasn't 8' wide. More like 7' 10 1/2". :mad: I have recently been lamenting a lack of displacement in my design and was questioning why I hadn't designed it to a higher value. The rediscovered (proper) Freeship file also has about a quarter tonne more displacement than the erroneous file so I'm very happy about that.

    That's all for this post.
     
  14. LP
    Joined: Jul 2005
    Posts: 1,404
    Likes: 56, Points: 58, Legacy Rep: 584
    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    Mast whacking.

    With the start of the new year, I feel that spring will be upon us before we know it. This spring (or summer, or fall), will hopefully mean launch day. Considering the state of the build, I feel this is a wildly moving target and recent acquisitions are intended pull the target in a little tighter. The next important acquisition that is going to make launch day possible is a set of sails. I'm hoping to locate a sailmaker that understands free standing masts and can make me a set of sails based on the dynamics of my masts. Oh, but wait. I don't have any masts. :rolleyes: Top priority in the shop right now is a pair of free standing masts. And that is exactly whats happening right now.


    i purchased some vertical grained douglas fir almost a year ago now. It's been stacked neatly and waiting patiently for the day when it's needed. The lengths are 10 and 12 feet. My main mast is 29ish feet long so it will take two scarfs to join a 12 and two 10s into a usable length for each stave. The masts are basic box sections. With the 1x4s (0.75" x 3.5"), I can go as large as 4.25" x 4.25" hollow square with a pinwheel(?) type stack up or 5" x 3.5" hollow rectangle with a sides and caps type stack up. The hollow masts within these design parameters are slightly undersized for my strength requirements, but I'm also wanting rotating masts and that will require a round section shape. With the additional "cheeking" required to make the round sections in way of the deck and pardners and judicious use of internal fillers, I can build my masts with the basic 1x4 stock I have on hand and no additional joining to increase the width. This cheeking will be extended up and down the mast as required to meet design load requirements.

    The first attempt.

    I went with a basic rectangular section that was 4.75" x 3.5". When cheeked out to round, this gave a 5.5" diameter which meets my strength requirements. The section was constant up to the boom attach point and then tapered in both directions to a 2"x2" section at the top. Rather than do a straight taper, I worked in a convexed shape to the taper and padded the fore-n-aft dimension for additional strength for a flown(?) sail. This addition was a guess at best. When all was said and done, I had a beautiful beast of a mast that weighed in at 75 lbs. for it's 29' 7" length. :eek: That wasn't going to cut it.

    I think that I can safely say that a usable mast isn't going to happen accidentally. With the first attempt, I had no idea of what to expect regarding stiffness and it was certainly plenty stiff. And heavy. Did I mention that it was heavy. My calculations were way off. I had to bump my material weight up to 40 lbs. per cubic foot to get my math to agree with the actual weight.

    The mast whacking begins. I pulled out the cutting guide for my circular saw (i never use the cutting guide) and set it slightly wider than 3/4" and ripped a 1" deep cut behind the forward stave of the mast. I flipped the mast and repeated. Set the depth for half the mast thickness and ripped through the filler areas in the mast and flipped the mast and ripped from the other side to remove the forward stave. It was a mast and now its not a mast. No. I take that back. It was never a mast. :!:

    So back to the spread sheet. No more fooling around. I went in and pared down the sections that I could and pulled out any extravagant excesses. The basic mast section was reduced to 4.375 x 3.5". About 1/2" of for-n-aft depth was removed and mast wall thickness was recalculated to 20% where it was possible. I thought I could sneak by with a constant 3/4" wall thickness. I did not adjust mast width as that would mean a complete disassembly and the for-n-aft adjustments took care of the major concerns and also brought the mast closer to a square section. Once the fore-n-aft dimensions were recut, I use my power planner to shave down the side wall thicknesses to near 20%. Prior to reassembly, the mast weighed in at 64 lbs. Definitely an improvement and the front and back stave are yet to shaved in thickness. At the moment, the CG of the mast is about 11' up the mast as the bottom 4' is solid wood. Or, another perspective, is the bottom half weighs 39 lbs. and the top half weighs 25 lbs. I think I'm getting it light where it going to count the most. Before the cut-up, the bottom half was 45 lbs. and the top half was 30 lbs.

    While it was unfortunate to have to dismantle mast, it was good learning experience and with no major material losses. I did let the circular saw blade go a little wayward in the dismantling process and undercut a small portion of the front stave. I back filled this area with layers of uni-cloth a la Payson as it was in the vicinity of the boom attachment and a structurally strategic location. Having the mast opened up in a U-section also made it very easy to shave the side staves and to monitor it's progress. I will plan to use the same method for the mizzen mast (without the disassembly portion :cool:).

    If all else fails, I will look into aluminum sections for my masts, but that will be the last resort.
     

  15. LP
    Joined: Jul 2005
    Posts: 1,404
    Likes: 56, Points: 58, Legacy Rep: 584
    Location: 26 36.9 N, 82 07.3 W

    LP Flying Boatman

    Re-laying the forward stave.

    A quick pic of laying the forward stave. In an effort to reduce waste, I start the lay at the foot of the mast and work towards the head. I scrape up the squeezed out epoxy and use it again as I work up the mast. It adds time to the process, but saves a fair amount of epoxy,

    Note the clamping blocks used to spread the clamping pressure. Easy does it though. Just enough pressure to bring the parts together.

    IMG_0441.JPG IMG_0442.JPG
     
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.