New Rig

2 Months since I posted the last modifications, I guess I am improving 🤓.

I mentioned that I would try to use my mainsail and rig that as a lugsail. And it worked! Although with some comments of my sailmaker as a lugsail needs a reinforced luff. I temporarily solved this with a Dyneema line connecting the forward ends of the yard and the boom alongside the luff limiting the tension. 

Now the sail was raised as a lug in about half a day and it looked very pretty already. 

But it took several weeks tinkering, testing and experimenting to make it a real functional lug rig. I experimented with the attachement of the halyard, the main sheet, the downhaul and a variety of other small features to keep the rig in place. And of course It had to meet a number of “Arjen”-requirements:

• Construction as simple as possible
• Easy to setup
• Trimmable
• Able to lower the mast easy and quickly without detaching downhaul, sail and halyard
• Able to easily remove sail, yard and boom in one package for dry storing

Short test

I took Narhval for a sort test on a nice 3 BFT day on the local canal (Van Harinxmakanaal) and I found it sailing surprisingly well! Easy, relaxed and comfortable without any noticeable compromise to the sailing characteristics. It even tacked easier and it seemed to be a bit more controllable as well. Of course this due to the shifted CE which worked as I hoped for. 

Mizzen

Although the boat sailed better balanced it stil seemed to be a bit leeward and that was what I hoped for too. I got courages and decided to implement a mizzen as well. I considered a few options for this sail and came up with a triangular spritsail. This sail is very easy and fast to fold down to the mast, it doesn’t require a long stern sprit and it lacks yard and boom. It also is trimmable with the tension of the sprit. I made it so that I only have to detach the sprit tensioner to be able to pull out the mast-sail-sprit-pack in an instant. 

Probably I have to trim the mainsail a bit forward now but as the weather here in the Netherlands has been “reset” to 5-6BFT and rainy I wasn’t able to test it in the current configuration yet.

One of the things I learned up till now is that the calculation of CLR and CE isn’t as easy and straightforward as it seems. Especially the CLR needs some reconsideration. I found lots of information on the internet usually calculating the lateral surface under water as a whole finding the CLR.

As the shape of the bow influences the frontal resistance the shape of the lateral resistance must have a similar effect too. More about that in a next post.

 

More of a builder than a sailor

Maybe I promised to have some more footage of being on the water with the Narhwal. I have to read the earlier posts to confirm that 😉.

In the mean time I can bring up lots of excuses why I havent been on the water more often. I guess cold feet is one of them, however I also discovered that I am more of a builder than a sailor. 

In the past few months I considered all kinds of building plans: From building a new boat from scratch to restoring an old ship and, to modify my Pocketship.

Findings that need modification 😇

Although I wasn't as much as possible on the water I sailed enough to get to know my ship better.

I discovered (as most Pocketship owners did) that the boat can be a bit leeward. The common applied solution is to trim the mast a bit back wich in my opinion doesn't effect much. 

Secondly, and that is a common Pocketship characteristic as well, is that the Pocketship has a relative slow turn rate for such a small vessel. In close hauled courses after tacking it is recomended not to tension the jib to fast as the boat slows down considerable and the rudder effectivity is decreasing. Adding up to the leeward tendency it is a bit tricky to keep the boat close hauled after tacking. I found out that in Strong winds (6 Bft) the effect is even worse loosing control completely bearing away up until a broad reach.

Now for the slow turn rate I guess the model of the rudder is one of the culprits. Of course it fits esthetically the nice classic lines and it ommits the necessity of a complex tilting mechanism.

Another reasson for the slow turning probably is the long keel streching over almost the entire lenght of the hull. Now the keel was an eyesore allready for a longer time and for several reassons: First off all it causes some trailer issues. As most standard trailers can accept V-shaped hulls, when it comes to even a shallow keel, the trailers have to be modified. I did a lot of tinkering to my trailer and even modified the front of the keel to be able to get the boat on the trailer smooth and easy.

Furthermore the keel also makes the boat sit quite high on the trailer but the most important issue is that you can't keep the Pocketship level easily if you beach the boat or fall dry on the Wadden.

The Pocketship showing this on the right is built by Bruno Lequeu of Dijon, France.

Now as expected my aluminum Pocketship is some heavier than the original wood-epoxy version. Therefore it sits about 1/2 to 1 inch deeper in the water which is negligible in the water. On the trailer however it can make a difference. But getting out the leas ballast can be quite an operation. So all in all I need to get rid of that keel someday 😑.

First major modification (plan)

The theory of reducing leeuwardness is simple: Either move the center of effortness (CE) backwards or the center of lateral resistance (CLR) forward (or both ofcourse). Moving the CE backwards means that the center of the complete sail-area backwards. When a boat is trimmed well, this can be done by minor shifts of the mast. My approach is a bit differtent: I want to shorten my mainsail by cutting a part of the leech and shorten the boom. Than add a small (unstayed) mizzen (see picture below).

Execpt from moving the CE backwards this way I also attain some more directional control.

Although not stricly necessary I also want to remove the boomgallows. It doesn't serve a purpose for catching the boom anymore and only for lowering the mast for trailering I make a removeable support, either apart or in combination with a divisible mizzen-mast.

Also the layout of the main sheet will change. The standard layout tends to "entanglement" either with other lines or with myself. So I want to implement one attachpoint on the boom probably with some tension divider.

After this modification I want to sail it a bit more frequent. The second major modification (plan) I will implement in 2024 so that I can tweak the plan with the latest experience. This will consist of trimming the keel, change the centerboard (longer and narrower) and change the rudder.

Finally: Sails

 One of the few things that I didn’t make myself were the sails. This is a complete different profession and needs different tools as well. 

Fortunately we have a very good sail maker - specialised in small home built sailboats - in the neighbourhood (Groningen).

Rigging was easy and I was very pleased with the result.

Oar & Sail

Mast boomgallows bowsprit boom and gaff

 What is there to say about making the wooden spars of the boat. Probably a lot with the risk of getting too much into technical details.

Apart from the mast it was quite straight forward woodworking. Shaping it needs appropriate tools and one power tool I lacked for a while was router. 

The mast was a bit more complex. Not only because of the accurate routing but also the gluing with epoxy needs a fair bit of attention. My main concern was to get the mast as straight as possible. Surprisingly the mast came out straight right away despite of the separate parts being crooked. I guess 2 (or 4) times crooked = straight…

Companion way (continued) and solar power

 As I mentioned in a earlier post I had to consider additional measures to prevent water draining into the cabin. I had a piece of pvc (?)  from an anti wearing mat for furniture. That neither welds nor glues very easy so after some fitting and testing I riveted to the hatch. The hatch now is complete rain resistant.

Solar Power

For the solar power it took a while before I found a flexible panel with the right size. Of course there are lots of small panels available but to have a reasonable output it became a quest for the biggest panel that fits on the companion way garage. And dat was not a standard size. Besides that lots of small panels were equiped with "so handy" usb connectors wich I - obviously - did not like very much because of the poor water resistancy.

The Charger/regulator was another aspect. I found a (very popular) model on the internet which could do the job considering the specs. Thes model apeared to be faulty and I had to replace it. My habit is always not to replace it with the same brand and model as it allready "proved" not to be completely reliable.

Below the faulty one where you can see the problem: output on the regulator 12.8 V and on the panel just a mere 7.8V ???

It now works very fine and charges a AGM battery of around 50AH. I mainly use this for the cabin lights, to charge my cell phone and tablet and for navigation lights.

As you can see in the pictures below the LED navigation lights creates i nice "christmas treee" 😀

The top light was a bit more work and creativity. I decided not to insert a cable into the mast during the build of the mast. I thought that would be possible afterwards as well. (which proved correct)

    

Yes the bulb is a LED too...

In the picture above you also see that I made some changes in the rigging as well. I plan to paint the top of the mast white in the winter.

It Floats!

Time for a new post

Hi there,

Been a while again but good news, I was busy with building rather than blogging 😀.
And yes I passed my welding exam and yes I learned a lot again while building.

As this design is well constructed and I guess drawn in a CAD program all the parts should fit like a glove. In a wooden version a gap of an extra milimeter or 2-4 is not a problem as you dab an extra dot of epoxy with filler to solve it. For welding it is important to have no gaps at all as that is the easyest way of welding.

So I learned 2 important skills: Bending and filling.
When to parts aren't fitting that means that the curve of the panels isn't right yet. But with these fish-like shapes it takes a while to find out where to bend (or stretch) in order to close a gap. And sometimes you have to bend a panel about two meters aft (or forward) from the gap. Now with a bit of experience I now am able to make the panels fit quite accurately. And - not a surprize of course - it smooths the curves of the hull as well.

Second skill is fillet-welding. Once I found the right settings for my welding machine for the various positions I was able to close the remaining small gaps with a fillet-weld. This gives me more confidence to get the vessel watertight after all 💦😂.

In the pictures below I'll show you some stages of the deck build up from the past few weeks.

Picture right: I was extremely satisfied that I was able to shape the bow section smoothly. I used the deck template for the right curves and it took some timber to get there. Aluminum doesn't react the same as wood and it didn't follow a smooth curve around the bulkheads. In particularly after I welded the bulkheads the panels waved in stead of following a smooth curve due to heath schrinkage.

In the cockpit and cabin area it was quite easy to make the panels fit. I allready spread the sides to fit the seat panels and just a last milimeter was needed to close all the gaps between the lower and the upper side panels. (picture below)

 Rest of the pictures is about building up the backrests and the aft cabin wall:

And final result of the transom made with a 22 mm aluminum tube:

New phase

Last months I was very busy preparing for two exams both after about a year of training.
First of all I am officially a First Aid Instructor now. Happy to have passed that exam. Not as easy as I expected and a few organizations depended on me getting this certificate.

2nd and ofcourse the most interesting one my first official NIL welding certificate TIG (GTAW) Aluminum. I passed the practical exam and I trust I passed the theoretical as well but I'll have to await the official message.

So... A big black hole (time warp) ending study activities and time for the next phase in building the first Aluminum pocketship.

I cut the top pieces of the paterns and will make some templates in a few days.
I try to order the next set of sheet aluminum before Christmas holidays so that I will be able to do some cutting and welding between "Turkey and Fireworks".

Too busy to build but there is some progress...

Sorry to say but I really was a bit too busy to do much on the boat.
As ever I do multiple courses. Still doing welding courses and an Instructor First Aid course.
Well, during exam times there's not much time left unfortunately.

But I couldn't resist to do some boatbuilding every now and then 😏.
Here are some pictures of the progress:

In these pictures I finished the bulkheads and the floor frames. I bended the floor frames to have some platform to fix the wooden floor. I discovered that it is much more precise not to do that but to weld a piece of L-profile instead. I can line up these pieces exactly. Now I have to correct the height with some filler pieces of wood. Not a big problem but extra work.


Bulkhead 7 is in the wood version a complet closed bulkhead which has to be cut out after installing. This is a very inefficient way in aluminum. In a next build I won't do this again. An L-profile crossbar, an extra floor frame and the cut out piece of bulkhead 8 will do the job perfectly I guess.

I also started the floor of the cabin. Working with wood again yeah... 

 

I absolutely enjoyed this. Took about a half day of work. Still have to finish the wood of course. Not sure how to treat the floor boards. Varnish? Tung Oil? something else?

Learning, learning, learning, deforming and welding process...

You can't imagine: my fulltime job is in (higher) education and I never learned so much as with this project...

Ok, that was to be expected for the good reasons that I am an unexperienced welder and that I try to build an intended wooden boat in aluminum 😎 but hey, would Columbus ever had discovered Turtle Island without trying "something else"?

In fact there is so much to tell that I don’t know where to start. All metals including aluminum deforms when heated. They tell you a very limited amount about it during welding classes, nothing about the size of a boat. So I have to learn my lessons during building-time and I can tell you: these lessons are very very interesting. I already experienced these phenomena with the centerboard-trunk but after that every weld caused its troubles. It troubled me a lot. Did I choose the right welding method? Did I really bought the wrong welding machine? Did I really do the wrong welding course?

Now a few weeks later I know the answer and of course as ever it is “yes and no”.
Why do most of the aluminum boat builders use the MIG welding process? Not because of the advantages of TIG but of the disadvantages ofcourse. First of all and most im portant the heath transfer. TIG is a slower process and adds more heath into the metal than MIG. The difference is not only significant but humendous (as I experienced). Second - I thought not very important - is that MIG welds with only one hand. In fact this has two important advantages: first you can hold the pieces into place while (tack)welding with the other hand. Turned out to be very very very handy. And second the “agility”. Single hand welding also means welding in narrow spaces, easy welding in all positions and welding left and right handed!



You guessed already I had to switch to MIG. Fortunately I could sell my TIG welder fast and for a good price and found a MIG welder with the right specs by my favorite supplier (HBM-machines).

 

Yep this is a professional machine and it’s about the same price as my TIG welder.

Now what about lessons? MIG is completely different from TIG welding. Aluminum-welding is aluminum-welding however. The metal behaves about the same. And the difference between no welding experience at all and some experience is much bigger than than the difference between TIG and MIG. They say that if you start with TIG (as the most difficult proces) you can learn MIG faster and I think that’s true.

"El Bow Wrestling..."

Has been a while but I haven't sit still. Tossed in the side boards and as expected the bow section is the hardest part. As I am inexperienced with aluminum bending, stretching and fixing I had to try a few strategies.

Slowly I am nearing the finish of the bow. Every next inch taking a bit more time and new approaches 😉.

Starts looking like a ship isn't it? Far from watertight though.