Monday, March 13, 2017
A new design commission from John Royall for an all wood Flats skiff
This past summer I received an email from John Royall of Texas in the USA. John asked if I would design him a flats skiff to fit his personal requirements, and could he have the rights to be the only one to build his skiff? Sure John.
John is a shipwright and works on sailboats and any other types of water craft that needs rebuilding. At heart John is a power boater and a past flats fishing Guide. This skiff would be his reentry back into the Key West fishing Guiding circuit.
What John wanted was a shallow draft design that would carry a 115 hp outboard in a slotted stern, Be able to be poled with a level deck angle with himself and at worst 3 other big guys on board in 6-7" of water. It had to be able to make the run to the Marquesa Keys from Key West which crosses channels that can be pretty rough at times in the winter months with its big chop in the currents.
He wanted big easy simple hatches, self bailing cockpit, a simple center console with a removable cooler in front and he wanted this design to have as Classic a skiff style as I could come up with but still incorporating my hull bottom design ideas.
And best of all he wanted to build this skiff in wood epoxy.
John said this skiff might be his last build and he really wanted something good to look at and to have lots of curves.... But still be a very practical flats skiff to Guide and fish out of.
This is the kind of design commissions I like to get. It's nice to have clients that really know what they want. John wanted the skiff to be 18' long. As you all know I'am a list guy so the first thing I did was make up my weight list. Ugh..... Lots of stuff going into this skiff hull. This boat would be poleable but at down wind and reaching conditions mostly with a full load. This is what I would consider a large scale technical skiff for heavy loads. My displacement numbers came to with a full load at around 2,200 lbs all up. I am glad I would not be poling John's clients around.
With this worst case load number in hand and the request of being somewhere in the 6-7" draft area I started my sketches and my displacement calculations for the bottom of the skiff. I knew what my bottom was going to look like right off. I wanted a flatish pad to get her to plane off quickly and to use the hull bottom sections from station #7 forward to take the seas and chop when trimmed down.
To get the displacement I needed I went to a bit more beam and lengthend the hull to 19'. The added beam would make this a stable craft with big guys aboard fishing the choppy channels for Tarpon and the added length was needed to make this work. The stern well slot John wanted and he had also asked for recessed trim tabs. They to me have so many issues that I gave my case against them but said I would design them in if he really wanted them. I won out. That was the only thing that I asked not to do in his design request. The added length was accepted knowing that all the extra weight would really effect a shorter hull. John had fished a Hewes for many years and knew what a stern down skiff was like.
A Hewes skiff is a fine boat but it just needs to be engineered to get some weight forward to help balance them out. This means building a lighter hull and moving the fuel tank as far forward as possible. And hopefully using a smaller engine.
With the hull bottom fleshed out I then drew in my bow and stern. The slotted well aft I would make as short as possible but still be able to get the engine in enough to get the looks and to be under the tower a bit. Truth is the slotted stern causes noise, and makes turning when poling a bit harder but if filling in the added displacement is very small, about 79-80 lbs gained. I gained this back by lengthening her a bit.
Next I looked at my upper chine line and how far off the waterline it was going to be. This is a very critical line. If too low it makes the skiff much dryer but can cause noise in choppy conditions with a full load. If too high... Well you get the chance of more spray making it over and around its outer edge.
To me this means you have to look at full loads and then at mid loads. This means the difference of 1/2-3/4". I like to get my upper chine lines at about 8" off the water at full load.
Next thing I do is draw in the sheer heights fore and aft. This skiff was to look like a classic if possible.
I drew in a slightly reversed sheer knowing I would draw in moderate flair up forward that would flow aft into a tumble home to the stern. The deck would have 1-1/2" crown to it to make it all flow together.
The look I was after was a bit of Carolina and Sea Craft melded into a Morejohn bottom.
Building in wood VS a modern cored hull means slightly different hull scantlings. When using wood it's a more pleasant build for the simple fact that to me wood is a natural feeling material and it transfers this to you when working with it. When designing in wood you can use the woods fibers and longitudinal strengths to your advantage. This means the skiff can be very strong. One difference between wood and core is the weight difference. This you have to add into your design displacement calculations. It's easy by just adding up the Square ft. Numbers and comparing them against each other. The hull skins in glass can be the same in most all places. The hull is to be planked up in Cedar strips using epoxy resin as the glue and hull skin laminating resin. I like to dry screw and fit my Cedar strips to the building stations and then squeegee in the epoxy after the hull is planked up and faired. I then fair when cured, roll a resin coat over till all smooth and when cured I then dry fit my cloth layers and resin coat in. After the hull is glassed and faired I then remove from the building jig and do the same process on the inside. After this I install all the bulkheads and finish off the build. Ha this is the short version.
I am writing up a blog in detail on how to do this. Soon come.
By building in wood you get the satisfaction of putting together a hull that smells and feels like a real boat. With core it's kind of like looking at a big styrofoam coffee cup made up like a quilt. A great way to go but not as romantic.
When building a technical wood skiff the problem comes back to weight and how to save it with the big flat expanses of the deck and cockpit floor. In keeping with the wood theme I like to glue core to a 1/8" skin of high quality Occumee plywood and then add a single layer of cloth to this for abrasion and strength. This makes building a skiff like this similar to building a one off surf board. If done in the proper sequence there is minimal grinding and it all comes down to finish fairing.
I will be posting a blog on this and will be incorporating all this info into a book I'am putting together on how to build my way, or at least the way I have found to be quick, cost effective, not so itchy, and doable by anyone.
I did my calculations on paper and then made up my half modle. From here I drew out my hull lines and from these I refined to the final set that you see here. By using my half hull method I get to see this hull from many angles just like you can see on a computer screen but the bonus is I get to feel up my vision with my hands. I can't imagine drawing up a fish on a computer screen in 3-D and then tapping a button for it to be spit out in a one dimension paper sheet for me to "feel up" then as a finished Vision.
I guess I am an old school half hull caresser and cuddler.
Here's the half hull on a boat John's working on. My clients get the half hull along with a PDF file and the age old set of print drawings to use as your guide to building " from scratch ".
All the below drawings and half hull pictures can be seen perfectly on hogfishdesign.wordpress.com
I draw out all my hull stations like this as my flats skiff hull sections are complicated. It would be very hard for an amature to draw out a set of hull lines like these from an offsets box. Here all you have to do is draw out an accurate grid plan and then look at the Allready figured out numbers.
This shows the hull build at all the station mold sections.
The hull build jig and set up for the Chines and bottom pads. These are plywood and you just set up the build stations and then set these down first. The hull strips get glued in next. I start right under the ply edges and glue the first strip to them. The strips then can be butted up dry from here on so you don't have glue all over the place. It's all shown on the drawings how and where to start.
This hull has a big fuel tank up forward that can be removed without hassle at anytime through the forward hatch. This is very important in skiff designs.
Typical hull sections shown in full size dimensions and details.
Chine details. It's the Chines that really make it all work, SO pay attention to these details when building.
John will build this skiff next winter. I am looking forward to seeing her come together.
I have built 62 different boats in my time by myself. 3 of those have been to others designs using their plans. My last build was to an Ian Farrier design of a very detailed Trimaran design. Ian's drawing are very detailed all done on a computer. But his info is all over the place. It was like a treasure map trying to piece all the info together. I got the feeling he only wanted the builder to know just enough to build his Tri. No hull lines drawings or any reference drawings. I felt he was scared to pass on too much information. His design had to be built to within 3mm or it would not work.
On one hand I liked that all I had to do was just follow his lead. On the other hand it was like a very expensive treasure hunt with little clues along the way.
When I draw out my designs I assume the builder has read up a bit on boat building terminology and the basics of boat building. It's a great process of taking numbers from paper and moving this to a finished project.
I am my most happiest building a boat alone. I have been very lucky to have had the opportunity to have been able to build a few boats on my own and to my own way of thinking. I am a loner and just like going along on my own. But to really get ahead in life I have needed others to help build my boats alongside me. With this reality having me bending over along side others training them in my methods I have been part of many more builds.... In the hundreds.
In my life the most satisfying thing for me using my two hands and a bit of brain matter has been drawing up a boat on paper and seeing it's vision all the way through launching and crossing an ocean in it to a new foreign land successfully.
Using another part of me I have the pride of having helped raise two Wonderfull daughters.
Different vessels different tale.