Building a 9 ft plywood dinghy

[@theWZZA]

I see that you've made another boat... I guess it is addicting. Some day I will join you out in SF Bay. You inspire me, Sir.

[@raw123yt]

Thank you. There is always one more boat to build. 🙂

[@marcelajaskova465]

Hello Ralph ! Nice work ! I had a similar idea. I increased 20 percent Jim Michalak Vole. I made the hull for a skeleton from Airex and epoxy resin. Because there is no frame inside the hull, I'm thinking about the cabin. I also used Optimist fittings to hang the rudder. Al Bilek

[@bulow453]

Nice work! I'm thinking a build along this same idea.

[@Outdoorslover1]

Love your work. I've got question : I've got simplicity 8 plans and I'm planning to make her bigger / longer using stitch and glue method . How do you exactly go about to make her longer? How many % I can stretch gap between stations? Originally they are spaced 305mm . Also do I only change dimensions of the panels which are placed precisely on the station lines? The dimentions of the panels which are not placed on the station lines do I live as they are? This will generat the conflict because it will depend from which station I take measurement from preceding station or following station. Looking forward to hear from you.

[@raw123yt]

Thanks. I don't know the max amount of stretch you can do. I increased my length by 18 inches which is about 20%. Before I did the stretch I emailed Paul at Selway-Fisher to check. So that is what I would suggest if you want to go more. He is VERY helpful. Both about modifying and building his designs. The classic version I built is done different from the stitch n glue method. My plans just have the position of the frames and temporary frames. Once the strongback/frame is built the bottom and side panels are then glued and screwed in place. Which I'm sure you saw in my video. In my plans the measurement varies between the different frames. To get the new position of the frames I input the original design into a boat design software and told it to stretch the length by 18 inches. Took that output, put it into a CAD program and added dimensions. The bow and transom measurements (angle) are referenced from the very ends so there was no change getting them installed correctly. I placed the daggerboard case in the same position relative to the center frame (frame in it's new position). Then I placed the mast relative to the daggerboard case so the distance between the mast and daggerboard is the same regardless for the length of the boat. I lucked out here because I'm using the sail plan from the Skylark 9 and the forward frame was in just the right spot. :-) ---------------------------------------------------------------------- So that is how I did my build. Stitch n glue is easier. Just increased the the station spacing. So 305 + N = new station spacing. Make all the station spacing the same. You just need to figure out what N is to get the length you decide on. Place the daggerboard at the center frame (I assume it is the same as my version) and then position the mast. Depending where the forward frame ends up you may need to move it to make room for the mast step. For the ends of the panels you may need to do a little fussing depending on what is used for a reference point for layout. If you keep the same angle at the bow and stern you should be OK. I have the full plans for the Skylark 9 and it's transom is referenced from the very end of the boat and the bow is referenced from the most forward station. Looking at it it seems like it should work out if I stretched it. The forward frame is moved but its relationship to the very end of the boat hasn't changed. I would suggest building a cardboard scale model of your final design. That will give you a good idea if you did your math right. ------------------------------------------------------------------------ I did an extra step for my build. Since the rear frame was moved it made the rear seat wider, which I didn't want. So after assembling the strongback with all the frames and the bow and transom panels in place I created a new rear frame (closer to the transom) so the rear seat was the same width as the original. I left the new front seat alone. -------------------------------------------------------------------------- I have build several stitch n glue boats and one thing that really helps assembly (stitching part) is to force the rocker into the bottom before stitching the side panel in place. For your V-bottom design I would stitch the bottom panels together. Place blocks under the ends and a big weight in the center. Then stitch the side and ends in place. You can get the rocker from the planes. Hope this helps, Ralph

[@JenkinsBoatWorks]

great job!

[@raw123yt]

Thank you

[@nikosntar265]

Great job Ralph! I can see you have built several dinghies including a flat bottomed (stretched optimist), a v-shape hull (stretched simplicity) and a multi-chine (skylark). I'm a complete novice but interested in a first time build, as simple as possible, able to carry 2 adults for fishing, able to move by oars for a while, and able to allow some sailing for me and my daughter in protected waters. In your opinion which one of the aforementioned hulls would suit me best? Thanks for your time!

[@raw123yt]

The short answer is a multi-chine hull is the best compromise between performance and ease of building. I will post a more complete answer in a day or 2.

[@raw123yt]

A rounded bottom hull is the most efficient shape through the water and has the best stability characteristics. And is probably the hardest to build in wood. The flat bottom hull is at the opposite end of the spectrum. It is the least efficient shape through the water. At low heel angles (or none) the flat bottom has good stability, but as the heeling angles increase the stability goes down (gets tippy). The flat bottom is the easiest to build and has lots of internal volume. The multi-chine hull, like the Skylark, is between the rounded bottom and the flat bottom boats. Paul Fisher of Selway-Fisher Design wrote in a post: "a good compromise and one which I often use is a flat bottom with 2 or 3 topside strakes" (panels). His Skylark design is a good example. The water sees the multi-chine hull as something close to a round bottom boat. More efficient through the water and better stability. A sharpie design, which is a flat bottom boat, would be a good choice if you want simple to build and you said you were going to be in protected waters. They started out as an oyster boat in the north east of America in the middle of the 1800's. The design has been developed and refined many times since then. Selway-Fisher Design has several of different sizes. Both Selway-Fisher and Jim Michalak have multi-chine boat designs for row and/or sail. Jim Michalak has several flat bottom designs. Warren Messer also is a good source for small row and sail boats. Jim's small boat designs are meant to be straight forward and easy to build. Both Jim and Selway-Fisher have books to help in the building process. I have both and have used them. Jim Michalak and Warren Messer designs can be found on duckworks.com and Selway-Fisher at selway-fisher.com. I don't know how large a boat you are thinking of but if you are thinking small, a design with a leeboard gives you more internal volume. Which might be important if you plan to carry 2 people. Daggerboard and centerboard cases are always in the way. :-) If you want to go super simple build you might consider a Puddle Duck or Goose Duck design. They are about as simple as boat bulding can get. There is lots of info on the web. Ralph

[@nikosntar265]

@@raw123yt Thank you Ralph for the answers! Really appreciate it! I have actually bought the plans for the Goose Duck but i'm quite reluctant due to the probably very poor rowing ability of this boat - otherwise since building simplicity is a top priority, i would build that. I like some of Michalak's plans - especially Tween and Twixt. Tween looks a bit small to me (8ft) and Twixt seems to have low freeboard (which is quite crucial to me - a higher freeboard would give a greater sense of stability). Messer's designs are interesting (e.g. Nuthatch 10ft) but it has a steep V bottom and i guess it may be quite tippy. I have also plans for the Pinta dinghy of Wave Dancer yacht design - i like the lines a lot but it seems quite difficult for a first project. If there were plans for a 10ft Simplicity, that would be perfect for me i guess. Otherwise i may go for the Skylark 10. Still confused... but thanks anyway!

[@raw123yt]

@@nikosntar265 Not sure about the Nuthatch being tippy. I've always thought of V bottom boats as stable. There are LOTS of designs using the V bottom. Some very successful. You can email Duckworks about your concerns and they will forward them to the designer. Creating a 10ft Simplicity is fairly easy. When you do your layout on the plywood just increase the distance between each station. It's a pretty common practice among home builders. Just keep the distance between the mast and the daggerboard the same. Or you could ask Paul at Selway-Fisher about creating a set of panel drawing for a 10 ft version. He is pretty helpful that way. I think the sail from a Skylark 9 or 10 would fit be a better fit. I have a set of plans for Jim's Piccup, which I'm thinking of building, and the sides are vertical. The description of the Twixt says it is based on the Piccup, so the Twixt may have vertical sides. If they are adding some height to them to get more freeboard would be pretty easy. Have you considered the Piccup? There are a few videos of it on KZbin and it looks like a capable small boat. I'm interested in it because I can sleep in the bottom. Ralph

[@tomshiba51]

This looks like a fairly simple design that can be built easily and quickly.

[@cid4887]

May i ask if the front flat part creates drag as it pushes the water as well as creates more splash towards the inside due to being flat and not that usual pointed one?

[@raw123yt]

This style of bow is often called a pram bow because it is used on prams (small dinghies). It is popular because it is easier to build and provides more volume overall and more volume in the bow. In most conditions the pram bow will be out of the water so it doesn't splash much more then a pointed bow boat. However if you do hit a wave with the blunt bow you will get wet. The part of the bow that is normally in the water does create more drag and splashing. In typical sailing conditions for a small boat, the splashing isn't a lot. Nothing a good boating sponge can't handle. I carry a small scope bailer sized for dinghies but I don't think I've ever had to use it. The sponge and a small towel are enough. You can see in the clip at the end that there is some splashed water but it's not a lot. And those conditions are probably rougher then normal for a small boat. I don't know how much the pram bow slows a boat. I'm sure it does but the boats go plenty fast enough to be lots of fun to sail. This particular design has a V bottom so that helps the bow cut through the water.

[@cid4887]

@@raw123yt Thankyou for info. Now i'll stick to my original build plan of making dinghy pram with flat front for it's easier to build as you attest.

[@lesp315]

Amazing labor of love.

[@raw123yt]

Thank you. Diffidently a bigger challenge then a stitch-n-glue build.

[@TotesNotTom]

Hello Ralph Woodard, really good video, love the ending where you showed some video footage of you sailing it. I have recently started repairing/building boats with my first video being released today, you're more than welcome to have a look, possibly suggest how I could improve things? Thanks Tom