Blackrock 24 (Build)

Bit by bit. The deck structure in permanently. Just a few more tapes to put in to tie the carlin to the frames. I've been bedding most of the structure with thickened CS and letting it cure. Then I pull the temp fasteners and fillet with a wood flour, CS mix and apply tapes while the goo is still soft. I screwed up yesterday by accidentally mixing a double batch of straight epoxy to wet out tapes. This really put the pressure on me to use the batch up before it was unusable. Lots of goo slopping that day and I have the dribbles to show it. Thanks goodness for a little foresight and a layer of contractors paper laid out before hand. Yesterday saw the final installation of the cabin's forward strong beam and gussets. I also managed to get the mizzen mast step bedded in.

Today saw the final installation of the deck carlins. A before and after shot is included. Fortunately, the pieces spring into place and stays without assistance. I only had to worry about gooing and springing. Gooing, springing AND screwing might have overwhelmed me. Thank goodness for small blessings. I did have a couple of extra hand for the springing process though. Left photo should have some clamped on 2x2's to wrap the carlin around until it drop!springs into place. Temp screws in each frame keeps it secure until the goo sets.

 

Teaser alert.

I spent most of my time yesterday finishing the carlin connections with uni-tapes. Again, I over-poured the epoxy and found myself in haste trying to use it up before disaster set in. I was able it pre-wet the tape locations to use up the excess before it got hard and have slightly tacky epoxy to lay the tapes into before wetting them out. Hand pumps are a pain for large batches, but pouring is a real pain for small batches. When pouring, I pour the hardener first and this sets my target for the resin portion. What ever I get with the hardener, I triple the indication when adding the resin to the mix. My scale reads to a tenth of an oz. so I try to hit my target or target plus a tenth. If I go over by more than a tenth, I take the overage, divide it by two and add that much more hardener. Egads! The small batches I try to hit on the money. One tenth over on a one oz. resin pour is a 10% error in resin. And that begs, how much hardener do I really have? Do I have 0.5 oz. or do I have 0.45 oz. or do I have 0.54 oz.? All possibly within the accuracy display of my scale. OK, enough of that. So far, it was all kicked off properly so all is well.

I was able to go get my final order of plywood yesterday. 11 more sheets. I still have four from my first order. I cannot believe that I need to put 15 more sheets of plywood into my boat. I'm hoping I have over estimated. I did try to be generous in my estimation since running becomes costly. Ten sheets gets a discount and shipping for 11 sheets is the same for one sheet in my case. Seriously hoping for left over ply.

Having said all of that, I was left with some large pieces of cardboard from the packaging. I put these to use to start a mock up of the cabin sides. I could do the whole cabin, but I'm mostly interested in the visuals the cabin sides present. The photo below shows a rouge visual of the side. My plan is to rip a single piece of ply into three 16" wide pieces and join them, end to end. With the flair of the cabin sides, I was able to have a nearly straight lower edge so fitting and trim is minimized. The image is the raw stock shape. Closer inspection reveals a horizontal line for a possible cabin height. Currently, at mid ships, the cabin height is about 2" higher than designed. Right now, I feel that the forward end of the cabin could stand to be a couple of inches higher and if I trim the aft end down, I will definitely need to add some spring to the roof edge. I'm tempted to keep the additional cabin height and hide it behind a tallish (2") toe rail. I will need to think more on this.

 

I gave up on pumps years ago. With small batches I prefer to use a syringe to draw out precise amounts. I use large gauge units from a feed store near me. On large batches, I pour straight from the tap into a container, sitting on a scale.

What do you think of the cabin side mockup?

 

Mock up.

I think that this is not a good photo to draw conclusions from, but with that said the midship cabin height appears to be too much. I have since done a priliminary trim on the mock up. I left it full height at mid ships and split the difference on the forward end. This gives it a nice up sweep on the forward end. I also trimmed the coaming portion. Both of these cuts really reduce the craft visually.

A bigger concern I have right now is the height of the coming and anticipated cabin top while seated in the cockpit. I'm feeling quite exposed. I plan to mock up the aft cabin bulkhead to get a better feel, but I may decide to lower the cockpit seating by a couple of inches.

I don't have standing headroom (planned) inside and don't expect to have it and I have plenty of sitting headroom with a lower coach roof. The real reason for raising the roof would be to have more cabin height in front of the cockpit.

I'm planning to use 9mm okoume for the coach roof and hope to get a fair amount crown to it.

The short answer though is its too tall as it stands right now and it will take some creativity to hide it if I don't cut it down in height.

As a side note: I think that I could have added a couple more inches to the sheer without making the boat look boxy. I believe my computer squished my boat lengthwise and made it look taller than it really is. No going back now.

Lowering the cockpit seating isn't too much of a setback and has a lot of potential. The coaming as I have it cut right now come up to mid-back(?) so a little deeper seating would have it come up even higher or I could allow me to drop the coaming height.

I'll post a couple of pics shortly with the trimmed mock up.

 

I agree it looks a bit tall to me too, though increasing roof crown can get back the headroom with lower cabin sides installed. Also installing hand rails just inboard of the roof edge will help hide it's tallness.

 

Here are a couple of shots with the sides trimmed.



Midship cabin height is still the same, but the ends are reduced. A slightly different photo angle also changes it's appearance, especially with the closeness of the photo.

 

When trying to make these decisions, I find it best to shoot pictures from the angles the boat will be seen from a dock. Assuming you have say 3' of freeboard above the dock, setup a ladder so you can shoot your shot from this height.

 

Three feet of freeboard above the dock! I don't even have three feet of freeboard.

Here are some things that are going on.

Top photo: Reducing the forward end of the cabin more. I have the roof line in my drawing pretty much horizontal, but the forward cabin looks rally short compared the the aft cabin. Fiddle, fiddle, fiddle.

Left and lower photos: Views from the cockpit. Left is from the helm station. Lower is the view. The top edge is what would give 6' headroom. Dream. Dream. Dream. The black line sets head room to planned 5'6". Roughly a 68" radius. The upper radius is about 50", I think.

Right photo: Adventures in torture. 9mm okoume ply with 23" of loft across an 83" span. Plenty of curvature for any coach roof that I'll be building. I've seen a process that uses towels and boiling water to relax/set some curvature to plywood panels. I'd have to do it to three panel so it might be a lengthy process and a new box to put a check mark in.

 

More playing with cardboard.

I've been pondering the floors (soles?) to my cockpit locker(s). More specifically, a method for for determining their size and shape. They are sloped for drainage and have two contoured sides. Recently, on another thread, I learned about joggle boards and endeavoured to make one. What a simple, but functional device! With only minor additional trimming in way of corners with taped fillets, the pieces practically fell into place.

I've been working with mocking up the cabin with cardboard, even the coach roof. Yesterday, I took the cardboard down and cut the pieces for the cabin sides and coamings. These are glued up and curing. I used simple butts and blocks as I have for most joints where I'm making longer board out of shorter ones. I will taper the edges of the blocks to make the joint as flexible as possible. I've also placed the joints over interior structure (v-berth and aft cabin bulkheads) to encourage a properly faired bend at the joint. It's a bit of a crap shoot, but I'm ok with it.

The photo of the day: The mock-up. I still have some extra loft in the cabin top, but I almost feel that I could get away with it. I am having to modify the cabin (coach roof) from my drawings since the coach roof I've drawn is not developable and I plan to use ply it that location. I have an ultimate height that I can't exceed that I have no control over: my garage door. 80" from the bottom of the castors on my holding fixture to the top of the hatch rails. Maybe less. I may be foregoing another SOR. Trailered height not to exceed the garage door height. That one is negotiable. I'm using more paint on this build than any other to make it a little (a lot?) more UV hardy so it can spend more or most of its time outside. If I don't get it on a trailer before it comes outside, I'll have to hire a lift truck to get on the trailer. It's tending in that direction if I don't go on a trailer mission in the near future.

So here it is. Once the cabin sides are on, I'll spend some more time getting the roof fully lined out/mock-up before trying to cut any material for it.

 

Nice work LP, she's definitely coming along well. You will have noticed how some ply bends easier one way than another, not all does, but do a static test by supporting each end on a trestle and putting a weight in the middle and measuring deflection. Note which side has the greatest deflection (if any) and use to your advantage. Does not always work but sometimes helps, also use the most deflection prone sheet for the most curvature.

Mark each sheet so it is used for the appropriate curved panel and each face so you know where any tendency to curve is ie outer/inner.

To my eye she is a little high still at the coaming side aft near the cockpit, but I'm more used to racier craft to be fair. One issue worth considering is making sure the height is not a foot trap, you don't want to trip on it when exiting the cockpit or returning. This also affect the width to the side rail, but it looks good there as far as I can tell. If you wanted local protection in bad weather, maybe a drop in (keyholed) semi Bimini might allow it, possibly a see through one? Just a little thinking out loud, most 24'ers are a little wet in a big sea on deck but not bad in the cockpit area per se as long as the craft has sensible freeboard.

Good to see some cardboard being used for mockups, wish more people did this sometimes. Gives real space, also light and other useful proporties, that are easy to miss, even with digital mockups.
Hope the weather stays with you to get a bit more of the build done.

 

Hey, Suki,

Thanks for stopping by. Even with the cardboard mockup, I'm still taking shots in the dark with the outcome of the final appearance. I plan to have a 1/2" by 1" or so drip edge with a nice big radius on the top to blend the top over to the side. The roof color will will wrap the drip edge and if it looks decent, I'll bright finish the cabin sides. So the true height (actual or apparent) is still kind of a moving target. I'm thinking the painted drip edge will give the illusion of shorter cabin sides. I love a low slung cabin for appearance reasons. Function and most likely, perceived necessity make me think I need something a little taller. I'll end up walking the line between the two. Hopefully, I don't fall down.

My side deck are a whole other story. They are fairly narrow at the aft cabin and expand in width as you progress to the forward end of the cabin. Aft from the cabin, they narrow even farther to where their only use might be to route a line to the cockpit. My desire was to have crew have the ability to sit as close to the rail as possible while still sitting comfortably IN the cockpit. To assist in dealing with the initially narrow side decks, I plan to apply anti-skid just outboard of the companionway as an alternate route for going forward and also I will have a forward hatch to work the main sail and anchoring if needed.

Side decks on small boats are like hallways in small houses. They are nice to have, but can eat up valuable living space. IMHO anyways.

 

Any colour difference along the edge of the cabin will help visually break up any percieved volume for sure, simply the eye reads component parts.

One important part of the cockpit is the seating and bracing. Quite a few carft have seats too wide or lack of foot bracing in the right place etc etc so going upwind in a lump can be an interesting balancing exercise. I'm sure you have considered this, personally I quite like being able to gently leg push (like in a relaxed way) so you are solidly held against the seat back. Just makes steering so much easier with a tiller or crewing if you need to alter either sheet or trim on the winch. Bit tricky to get this right at your length, depending on aft sleeping arrangements, on this I'd probably err on ease of sailing and fractionally compromise quarter berthing. After all your only in there to sleep not live in that area...

One solution I quite like is pushing with the leg on the seat opposite right on the corner but sometimes this means too narrow a cockpit floor. I have been on craft where you are simply pulled across by any sheet and you end up bracing yourself far too far down to leeward.

Your call, but you have the craft there, and it is always quite possible to add foot bracing/stops to suit. You are right to think about ease of getting out of the cockpit to do whatever needs doing forward etc etc mooring for instance. I'm sure your thinking will give a fair solution that will work well in practice.

 

With all of the mocking (up) going on, I've taken the opportunity to get my girlfriend (wife) into the cockpit for her to visualize what's happening with the boat. Also to see how she fits in the cockpit. Her stature is less than mine and we pinpointed some aspects that could be tuned to make her more comfortable there. The cockpit well is relatively narrow, but the seats are a little on the deep side (athwartship) and while I can brace easily to the opposite seat edge, it is a stretch for her. I think this is easily solved with a throwable placed behind her back to shorten the bracing distance. I am also entertaining the idea of a permanent firm, padded, upholstered cushion that hits you in your lumbar to help shorten the distant and give some nice back support where it's needed. The other area of concern was the depth of the footwell. It was placed deep on purpose. The kicker mounts to a bulkhead at the aft end of the cockpit and I have hopes of using a a short shaft for aux propulsion. A lower CG would be a nice benefit of the short shaft. My ultimate backup plan is to have a grate in the footwell to keep the tootsies high and dry, but will drop the seating height a couple of inches provided it doesn't limit forward visibility. And, forward visibility is determined by cabin height. Round and round we go.

Other excitement: the cabin sides glued up nicely and while they are curing, I took the time to fair and smooth more of the deck structure in preparation for decking. I laid out a sheet of the 9mm meranti and screwed down to mark it for cutting. I was pleasantly surprised at how rigid it is to walk on. I originally planned to use 12mm (1/2") ply, but after working with it for other components, decided it was heavier than needed. The weigh savings will be in a excellent location. If I was to to start from scratch, the are several areas I would reduce the scantlings on this build. Fortunately, most of it is down low and will add to stability. Work called me away before I could do much more than simply screwing down a piece of ply. Cutting out the deck should go quickly hopefully attaching will not be overly tedious.

It's beginning to look like I will have left over sheets of ply so while marine ply isn't cheap, every sheet that gets left off leaves that much more room for ballast or beer. Or my personal favorite, Flor de Caña rum. The seven year vintage is like liquid candy.

 

Picture of the day.

This picture may be hard to visualize. It's looking up under the deck at the fore cabin strong beam.

There is actually a lot going on in the photo. My forward cabin bulkhead is canted forward by about 30 deg. Rather than using some complex architecture with highly loaded, strong dense woods, I chose to go a little more bulky with lighter wood. S or P from the SPF family. You can see the plywood frame. The strong beam is mounted to the aft side of this and is triangular in cross-section. Zero thickness at the top and 2"-3" at the bottom. Simple, but gives a nice structure to mount the forward cabin bulkhead to.

Then you see my "knees" for bracing the strong beam. I may have had a Bueler moment with these. (No disrespect, George) Again, I did bulky with less dense material; straight up 2x material. With fayed glue surfaces, more is better. All of the joints are wrapped with biax. The stuff (biax) forms to complex shapes amazingly easily. All you really have to worry about is insuring properly radiused corners.

The frame is hanging down a little from the strong beam. Once the foreword cabin is installed, I'll do a final trimming to give it a singular appearance.

At the top of the photo, you can see the cabin side in place. You'll also see a gap between the lower cabin edge and the carlin. This tapers to zero at the top. The carlin was unwilling to take the orientation I wanted and I was unwilling to fight with the carlin. I'll be making a tapered shim to fill most of this gap to avoid using copious amounts of goo mix.

Right now, the deck is only fitted in place. To the right is a doubler that backs a deck seam. To the left, the seam is barely visible. This too will get "doubled" to reinforce the joint. When I install the deck, I plan to fillet and tape it with more biax. The biax tape is very rough if not sanded and filled. I'm hoping to use this to my advantage as I plan to insulate to deck with 1 1/2" to 2" of rigid foam. The harsh texture of the biax tape may prove to be enough to hold these pieces in place if fitted properly. Or, at least until the glue sets.

Ok. I that that just about covers this photo. Enjoy your Sunday. Thanks for dropping in.

 

Cabin sides

The cabin sides are rough fitted and trimmed. I smoothed and faired the top edge to satisfy my senses. The top edge will eventually be trimmed and beveled to match the coach roof. Smooth and fair suits my fancy until other progress is made.



There is a lot of thinking and planning going on as I attempt to finalize the topsides of Blackrock. I have a small list of items that are evolving as the build progresses. I'm pretty much committed to lowering the cockpit seats by two inches. The benefits of this are manifold. I am extending the cabin aft by 12"-16". This increases interior volume and give me space for a primitive nav station and electronics near the companionway, but protected from weather. I am stealing from the cockpit to do this, but I am still left with close to 7' of cockpit length. This change is a little more complex, but I am working the process. A final change that I am seriously considering is the layout of the cockpit area. It is currently designed with standard bench style seating running the length of either side of the cockpit with cockpit storage lockers under one or both seats. I am tempted to run a bench across the aft end of the cockpit and extend the width of the footwell to the full beam of the cockpit. Then, again have bench seating along either side for the forward half of the cockpit. This would give me room for a small binnacle central to the aft part of the cockpit. I have a bronze ships wheel that I purchased years ago without having a place to put it. I haven't worked though all of the details for the change and will modify some aspects of the current design so the cockpit can be built in either configuration or change to the binnacle'd version at a later date with minimal headache.