I was wondering if I could get a bit of feedback, or a few questions I have answered about building a small ( 4' x 11') flat bottom boat. If I make no seats in the boat, will just the epoxy coating and the 'but joints' with cloth be strong enough? From a structural stand point, not having a midship thwart and a bow piece (breast hook, foredeck or thwart) the sides of the boat will likely flop around a good bit. It would be possible to have a small thwart at each end of the boat with reinforced sheer clamp and maybe a topside stringer, to provide the open layout you desire. Location: maine A 4 foot wide boat as described would have quite a wide bottom, and it's strength (to resist transverse flexing) would be achieved by having a reasonable amount of rocker or making the seats full boxes for flotation and a set of transverse beams. In your case, wanting to have a clear open area, you can't just modify an existing plan without help from someone knowledgable. PAR will, I'm sure, provide you with a good set of plans or modify to suit, but by all means maske sure the bottom is rigid enough and that the connection to the sides is well braced. In the future, I may purchase plans and modify them to suit my own design, but for this first project, I think I'm going to just go with this basic design and consider purchasing plans in the future for something a bit more complex, even though I have questions about this 'simple' design!
One of the goals of this little project is to just keep it as simple and cheap as possible for now. In the attached picture, there is the rough outline and dimensions, as well as the proposed 'skeleton' of the boat made from 2x2s. I would be putting cloth and epoxy on the outside and inside of all seams, but should the entire boat surface be coated as well, or just the seams? Again, the boat will be used for shallow, calm water, and will have rub strips along the underside for added stability and for protection from rocks etc. Location: Alliston, Ontario, Canada At the very least put a bit of curvature in the bottom as it will help stiffen it and prevent oil-canning.
A bit of a curve will do the same thing for the sides: they do not have to come all the way in to a point at the bow. It is actually easier to do it this way than the way you have sketched: ply bends easily and it will save you have to make joints that are strong enough and waterproof.
Use seats as frames, and hide flotation in them Three cavities, both bow and stern shelves and the center thwart (seat). Location: Ontario Hey, It's been awhile, and I thought I'd update this thread with what I ended up doing. First, thank you to everyone who gave their advice and input in this thread, it was much appreciated, and much needed. I decided not to put seats in it, because I want the space for carrying things I have in it, but I included a 2x2 across the top and bottom near the middle of the boat.
I have more pictures I could show, but it seems that I'm at my size limit here with the 3 pics I've already posted in this thread. Anyways, I wanted to come back to say thanks, and also to show you guys what I ended up doing. When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Location: Eustis, FL Off the top of my head, I don't know of any single skin 'glass designs like this, but I could be wrong. The next step is to tape the seams with the Biaxial tape and sheath the entire bottom with the 9 oz wide woven cloth. Begin by cutting all your tape pieces to length - lay them out all dry before mixing any epoxy.
30 minutes later (or when ever the epoxy has become tacky) is the right time to lay your tape onto the seams. Where multiple layers of biaxial tape overlap (bow and transom), wet out one at layer at a time. An optional step that help to save on fairing time is to cover the wet glass with plastic sheeting.
I know the mold comes from the plug and the mold will not actually be a part of the boat right?
Can some or all off the products i need bo gotten at a big hardware store (lowes-home depot) or will i have to order them? Location: Carlisle,AR Im making it from my own design from what ive seen on the river boats on the rivers in north Arkansas trout waters. Location: Monroe WA I live on a river in WA and have several jet bots at my house (not all mine), I also lived in Arkansas for a short period of time and no one was ever able to answer my question as to why they use such narrow hulls.

The cost and effort involved in making a one off hull is pretty high, so if you're trying to save money it's not the rout to go. Originally Posted by ondarvr I live on a river in WA and have several jet bots at my house (not all mine), I also lived in Arkansas for a short period of time and no one was ever able to answer my question as to why they use such narrow hulls. Location: Monroe WA It sounds correct, but the rivers we run are shallower, rockier, tighter and nastier, with a large number of boat builders to help perfect the design. Here 99.9% of them are made from aluminum to take the abuse they get and there's no way you can get by with a prop, even a short-shaft outboard would be a no-shaft outboard in about 100 feet. They use narrow hulls to cut back on gas usage the 9.9 's they run will push them narrow hulls pretty darn fast without burning much gas. Oh and one reason they dont run alot of jet pumps is when the river is low you have to run the shallow gravel bars and the risk of sucking up some gravel runs pretty high. I've been on those rivers and that's what confuses me, from 40 years of boating my local waters here and doing a little (and I admit very little) boating on the ones in AR, I don't see why a wider jet boat wouldn't be a better option for getting around in difficult areas. Fuel consumption is a big issue with a pump, so I can see why someone would go with a prop if possible, I would too if it was possible to navigate our rivers with one. I don't want this to be an argument, I'm looking for the actual reasons each area use such a different style of boat to do the same thing. Like I said before, this has confused me since I lived there for a short time about 12 years ago. One thing I was told when I asked about it when I lived there, was the first guys to fish that method had a narrow boat and when the method caught on, others thought it was what you needed to use, so it stuck. Boats here have gotten wider over the years and it helps a great deal, so don't be afraid of going wider. Its not that hard to build the type of boat i want so ive been told by my uncle who built one many years ago from another boat they used for a mold.
It would be very costly and time consuming to make a mold for just one or two boats, it would make the $9,000 figure look very reasonable. For more info on jet boats, or river boats go to some of the salmon and steelhead fishing sites in the NW. You'll have to post some side view pictures of the hull shape you want before I start working on this, because I cannot tell much from that picture in your first post, and if I'm going to make this effort I want the results to look good to you. If you want a design that will give you a shallower draft than a typical flat bottom boat I can put a bottom on it that looks somewhat like the attached image.
By the way, the boat you asked for (flat bottom with a 5 foot wide beam at the waterline and 20 feet long) will not plane with a 9.9 HP engine so if you want it to plane you'll have to use your 25 HP engine. Location: Coastal Georgia I built a fiberglass flat bottom jonboat years ago using the foam log beam method that at the time was under patent by Carolina Skiff. Jon gravy holder that I made into amp duck boat during the summer of 2010 duck boat scissor blind. You could make one from your own design and it would perform to some expectations, but you could also get a set of plans (I have low cost plans for just the boat you describe) that will optimize the shapes, keep it simple to build and answer your questions about how thick things need to be, plus where to precisely put them. I've spent a bit of time reading the forum and looking at other 'jon boat' plans on the net, and I've modified my initial design. Does this plan look stable enough now, or are the few 'extra' transverse beams that I've now included overkill since it will be epoxied?
The entire underside would be epoxied of course, but does the entire inside need it as well, or just the seams? Curvature can make the ply act as if it was twice as thick, without the weight and cost, and it will go faster and smoother. If you make the front plate (pram transom) slope a bit the boat won't come to an abrupt stop when you run into a wave form a bigger boat (see PDRacer again). Well, I realized that my square design that I had initially come up with wasn't going to cut it, so I took the advice to make some curves in it.
I used a lot of epoxy on the bottom, more than I should have, but it was my inexperience at 'fiberglassing' that caused me to use so much. There are likely a few foam cored 'glass designs in this size, but this is a more costly way of building a small boat, not to mention you have to enjoy sanding and itching.
Your laminate will be cleaner, stronger, and use less epoxy if you wet out the wide cloth while the taped seams are not yet hard.
While pot life is limited, once the resin is spread on the hull, it will stay workable for quite a long time. Fiberglass ect will be applied to the inside of the mold and will come off the mold eventually?

Think about it if you had a guide service with 20 or 30 boats wouldnt you want to cut you gas usage by half or more and on most days the boats on the river 50 to 75% of the boats are guide boats so thats why there are so many narrow hulls. These are sometimes mounted a little higher than normal so you can get into shallower water.
I found one company that makes the 60" wide but to pricey for me $9000 just for the boat no trailer and no motor! It's not that difficult to cut a 54" hull down the center and make it wider, so that may be an option.
Since the shape of the boat was developable from flat sheets (like plywood) with no compound curves, I skipped the process of plug making and made a mold directly of (1) A 4 x 16' wood base of 2-2x8's with 2x6 crosspieces every 24" that was set on short blocks at a good working height. Been working on for anyone who is interested in building their own boat blind duck boat scissor blind.
This is a aggregation of terminated 50 boat building plans inwards PDF files zipped inward one and only Flat Bottom Wooden Boats. I plan to put narrow 'runners' on the bottom of the boat for extra stability and protection from rocks etc. I know it dries very hard, but I want to know if the way I'm picturing doing it will be ok.
An added benefit would be better performance from the little outboard and improved maneuverability as a result of the shapes employed in the design.
Most ply boats have a stiffening member along the top (sheer) of the side planks which is called a gunnel. Probly will just make 1 boat but keep the mold in case i want to build another one mabey for a family memeber. One more reason is the locals that own there own boats may go on buffalo river and when she gets low some places may only be 10' -15' wide with a tree also intruding out from the bank in the way a wide hull would be hard to get down. Is there a HP limit on the rivers there, some lakes here have them, but rivers don't, so a common motor for a 20' jet boat here would be a 200hp tiller Merc or Yamaha.
There are also some skiffs made in the South East that may have a hull in the size you're looking for. That was coated with polyester resin, sanded smooth and then waxed with the rest of the mold. The boat was set up with a astuteness view finder bow get on trolling motor ii live to get to work on overhauling the boat and making a scissor blind for it. Fast with lowly outboards rattling stalls easy to build Can be made free plywood flat bottom jon boat plans. You may find that it will be fairly easy to twist it without any bulkheads to give it rigidity so a couple of knees from side to bottom might be in order to help with this.
Don't even need any FG on the bottom unless you're going to run it up on bad jagged rocky beaches. This boat would be 8' feet wide and very open so you can move around easily while fishing, some guide boats even go to 300hp on slightly longer hull. The large motor with a pump is used to get up river, or at least to other locations, through shallow water, their may be up to 6 people in the boat so more hp is needed. One want to put it I would have to harmonise group A scissor manner blind is amazing in a First ane picked up this gravy boat trailer and centrifugal for 150. 4 hp is just on the border of enough to get you planning if the boat is light enough but I bet not so internal framing is not so necessary. The sheathing is good for abrasion protection though, especially if Xynole instead of 'glass is employed. This was angstrom unit one also made iodin Artium Magister in need of about direction for building type A duck sauceboat blind.
It's not the pebbly surfaced fiberglass stuff for commercial bathroom and kitchen walls, but the hard, dark brown masonite with a smooth white coating. The Bondo was mixed, spooned into a plastic sandwich bag, the top twisted shut, a corner snipped off the bottom of the bag and the Bondo squeezed into the corners like a pastry icing decorator thing for writing on cakes. Both the clay and the Bondo were pressed into the corners and finished by sliding a tool socket of the correct size along the corner.

Design of boat hull
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