Challenge: The 100$ boat!

[dump-box]

Ok I hate to be a snot about this buuuut...Hypothetically if you had the time, the forest, and a chainsaw (or a timber saw by hand even), plus standard carpentry tools, a lathe (could be a really crude hand made lathe) a plane, Ax and Az, draw knife, and a few different wood saws, and a LOT OF TIME, I bet you could eventually make the HMS Bounty. You don't need any fasteners to build a boat, check out traditional Japanese construction method to carpentry or furniture construction. Actually, you could use hardwood pegs made from branch pieces in softwood (done right they are hard a nails).

Ok that aside, my cuz use to make all kinds of toys, when he was a boy, with pallets discarded behind stores. Both the timber and the nails were recycled into rafts, ramps, treehouses, forts, and a whole myrid of stuff. Art Center Design College had a design competition for the best furniture made from 1 wood pallet, and you wouldnt believe the great stuff those kids came up with. Looked like IKEA furniture you would buy!

That being stated, with enough time, creativity, and design, I'll bet you could make just about anything.

I have been kicking around an idea for a monohull (or a cat, or a tri) that would be like a traditional airplane (like a B-24 bomber from WWII) turned sideways, utilizing some mighty radical tech (by nautical standards anyways)
such as a self-trimming wingsail (see http://www.sailwings.net/article.html), coupled with a wind turbine assisted in a small necelle (just like a B-24 only further up the wingsail and a LOT bigger). Frankly, given the ridiculus amount of thing I've seen thrown away in my state, I'll bet I could salvage all the parts I'd ever need to build this for 100$ (if anybody wants to lend me a boatyard construction sight to find out let me know - might be there for a looong time though).

Course launching such a boat would cost a lot more then 100$. Hell I saw a tri sitting abandoned in a boatyard a few years ago. There literally was a bum sleeping in it. I'll bet you could get it to float for 100$. (regesteration and salvage claim fees gonna cost 100$ easly).

[dump-box]

Ok I hate to be a snot about this buuuut...Hypothetically if you had the time, the forest, and a chainsaw (or a timber saw by hand even), plus standard carpentry tools, a lathe (could be a really crude hand made lathe) a plane, Ax and Az, draw knife, and a few different wood saws, and a LOT OF TIME, I bet you could eventually make the HMS Bounty. You don't need any fasteners to build a boat, check out traditional Japanese construction method to carpentry or furniture construction. Actually, you could use hardwood pegs made from branch pieces in softwood (done right they are hard a nails).

Ok that aside, my cuz use to make all kinds of toys, when he was a boy, with pallets discarded behind stores. Both the timber and the nails were recycled into rafts, ramps, treehouses, forts, and a whole myrid of stuff. Art Center Design College had a design competition for the best furniture made from 1 wood pallet, and you wouldnt believe the great stuff those kids came up with. Looked like IKEA furniture you would buy!

That being stated, with enough time, creativity, and design, I'll bet you could make just about anything.

I have been kicking around an idea for a monohull (or a cat, or a tri) that would be like a traditional airplane (like a B-24 bomber from WWII) turned sideways, utilizing some mighty radical tech (by nautical standards anyways)
such as a self-trimming wingsail (see http://www.sailwings.net/article.html), coupled with a wind turbine assisted in a small necelle (just like a B-24 only further up the wingsail and a LOT bigger). Frankly, given the ridiculus amount of thing I've seen thrown away in my state, I'll bet I could salvage all the parts I'd ever need to build this for 100$ (if anybody wants to lend me a boatyard construction sight to find out let me know - might be there for a looong time though).

Course launching such a boat would cost a lot more then 100$. Hell I saw a tri sitting abandoned in a boatyard a few years ago. There literally was a bum sleeping in it. I'll bet you could get it to float for 100$. (regesteration and salvage claim fees gonna cost 100$ easly).

[ancient kayaker]

So, step up to the plate, mate!

[jpgilman]

Petros - All I can say is brilliant! I'm just finishing up a Yost kayak with my kids and my daughter wants to build a sail boat. Last night it hit me that I ought to be able to take plans for any lightweight boat and go the SOF route. I think you and Brian Schulz at Cape Falcon make a pretty convincing case. Couple of questions about construction

14' is about what I had in mind. You suggest 3/4" stringers for a 10' boat, what were the scantlings of your boat? It looks like you lashed the stringers to the ribs, did you use any adhesive? Finally, anything you would change in hindsight?

John

Originally Posted by Petros

You can take any small boat design you like that uses flat panels (hard chines) and covert it to skin-on-frame construction. I just took the dimensions of a high performance sailing dingy and scaled them for my hull shape and built it just like a skin-on-frame sea kayak. For a boat under 10 ft you can get by with gunwales and a keel of about 3/4" x 3" and stringers of about 3/4" square. You can use plywood to make frames, or do like I did and steam bend ribs with plywood frames about every 2 feet to help hold the shape.

[ancient kayaker]

A skin-on-frame boat is about the only way to do a boat larger than a canoe with store-bought materials. My next boat will be starting shortly, a tiny 10' sailboat, but even at that small size and half-price marine ply (the supplier had a flood so it's water-stained) and my cheap instincts it's going to come in above $100.

JP: I suspect a SOF boat has to be more flexible than a ply boat in order to absorb shock, as the overall strength is less. Therefore it may be a good idea to use just lashings. Lashings can be seen in the photo of Petros' boat. Glue in the joint would stiffen it up so that a heavy impact might break a structural member. There's a nice SOF boat taking shape in this thread, it has reached the rib steaming stage and is worth following:- http://www.boatdesign.net/forums/woo...-new-post.html

[Petros]

Originally Posted by jpgilman

Petros - Couple of questions about construction

14' is about what I had in mind. You suggest 3/4" stringers for a 10' boat, what were the scantlings of your boat? It looks like you lashed the stringers to the ribs, did you use any adhesive? Finally, anything you would change in hindsight?

I used the lines from a one-design racing sailboat called a K-18, and scaled them down to 14', and I made a few minor adjustments certain dimensions to increase the free board height, transom, etc and it is now a hard chine design.

I do not think I would change anything, other than perhaps to make it lighter (I can heft it on to the top of my car alone, but if it was a bit lighter it would be even easier). It takes more time to remove unnecessary weight to optimize each piece without affecting strength, so I am not sure I would want to take the extra time. I might do some of the hardware details different, but what I have works just fine. I have altered the main sheet several time until I was happy with how it worked (simple is best!), and messed with the jib shape several times (part of sorting out the rigging really), but the hull has been unchanged except I put in better cedar floor boards from what I first used (not shown in these pictures).

It uses 1x4 (3/4 x 3-1/2) for keel and gunwales, and 3/4" stringers, and I am happy with the strength. the keel and gunwales are glued and screwed through gusset blocks to the frames every 2 ft, the screws were installed "wet" with Tightbond III glue. All of the stringers are lashed with polyester lacing cord (do not use nylon-it stretches too much and it works loose).

A light weight skin-on-frame will flex more than a hard shell and I think the lashed joints are stronger than glue or even screws anyway, and allow some flex without risk of splitting the stringers. They are also faster to make than counter sunk screws. Despite the light weight and flex, this type of hull is much more damage resistant than a hard shell, the flex absorbs impacts and reduces peak impact loads. The redundant stringers are also "fail-safe", a broken stringer or two, or even a cracked keel do not affect sea worthiness, so you can put off repairs until it is convenient. The slight flex makes the ride a little more controllable in rough water too.

I built it almost the same way a skin-on-frame kayak is built, I added the frames to stiffen it since there are not deck beams in the cockpit area. And I worked out a way to end the stringers and gunwales on the transom using triangular gusset blocks and screws/glue. I used no plans, just built to the scaled dimensions and work out the fit of each part as I went.

[jpgilman]

Makes perfect sense. Thanks

[boating4fun]

I don't think it would be fair to post a time limit on it but instead allow a 3 month or 90 day time limit that way people could work on their boat project and still focus on day to day daily living. also I think it would make sense to allow people to post a pic of not only their boat project but also a pic of their receipt showing how much they spent on their project... perhaps one could also use salvaged or restored parts like motors, steering console, hull and what not

[Jelle]

This is an old thread, but I just had to register and show off my cheap but elegant rowboat, that stays well below the 70 dollar mark:
http://www.instructables.com/id/Fab-...-materials-70/

[mygoldfish]

Hey i know this thread is super old and keeps getting bumped up, but I thought I would post my experience with $100 boats!

It's definitely possible, and even easy to build a boat for $100, even from new, off-the-shelf (not scavenged) materials.

I'm 19 years old and as of two years ago I had VERY minimal materials with powertools and NO experience with boats/boating/boatbuilding. With my dad's help, my older sister (21 yrs) and I designed a boat for a competition they have on Lake Union in Seattle every year, during the Center for Wooden Boats' Wooden Boat Festival. That year (2009) we built a canvas-covered kayak, approximately 14 feet long, for $70 (if my memory serves). We used only a few basic tools (tool weight is one criteria in the competition) and it took us 9 hours and 9 minutes to build it. We raced it the next day and came in first place, proceeding to win the competition as well as the people's choice award.
We built "trigger" out of one by twos for the frame, covered in a canvas painter's dropcloth which we coated with some paint to seal it. The sail was more canvas with a 2x2 used as a mast.
this is my sister and I getting our first sailing lesson ever...half an hour before the race started. lol


Then, last year, my boyfriend built with my cause my sister couldn't and we built a pretty basic plywood dory in 3 hours 11 minutes. It cost us approximately $80, if my memory serves. Once again, the boat brought us first place in the race and we won the competition. There was no People's Choice Award that year (2010) because there weren't sufficient votes, but we were informed by the man who runs the competition that there was ONE vote, and it was for us.=]
This boat was just some quarter-inch plywood thrown together with a beach umbrella used as a sail (because we had a beach theme this time...the umbrella worked great as a sail! i'm glad i thought of that!).
You can see us in this picture near the back/center.

more detailed shot of the boat:

and one of us building it, just for fun:


see - $100 boats are totally possible...quality ones, too, and quick ones - and they're easy!

[ancient kayaker]

The thread endures: thanks for keeping it going! Great looking boat. I often take a collapsing umbrella with me when I go kayaking and I sail downwind on the first leg if I can. That ensures that I only have to paddle into the wind in one direction - and sometimes the wind changes and I get lucky!

[NoEyeDeer]

Nice work on both boats.

[ancient kayaker]

This 12 foot (3.7 m) canoe represents a different approach to my previous marine plywood and cedar boats. I am using it to try out a new (to me) method of both design and construction.

The bottom is cut from a 1/2 sheet of ply, the ribs are laminated clear pine, the stems are fabricated from pine and the curve of the bilge will be strip-built with 3/16 x 5/8" (1.5 15 mm) x Western Red Cedar. Then the ply cut-offs left over from cutting the bottom will be used for the sheer planks. everything is glued with a water-based glue, epoxy will be limited to sealing where required.

The ribs all have the identical profile so they could be formed over a common jig. That approach saved the cost of the plywood for the station molds which are not required with this technique. 8 short ribs joined to the stems will be added later.

The WRC is simply fence planks from the local hardware store - not too many knots despite the cheap price, and the strips have the proper vertical grain orientation. The pine was left over from my sailboat build - not on this thread because it went a bit over $100. The marine ply is from a stack of water-stained stock that I bought half-price a while back. I will not put glass and epoxy on the hull, just varnish and house paint so it will be well under $100.

I have hopes that it will have a nice antique 19th century look with those ribs on the inside. More pics later ...

[Raggi_Thor]

Really good looking, and an interesting method.
Deserves a greater picture

[NoEyeDeer]

Somewhat off topic but.....................

Quite a few Australian beach boats used to use a system of batten seam carvel below the waterline and clinker topsides. Boats planked like this tend to look rather nice IMO.

The reasoning was that the batten seam carvel was more watertight with changing moisture content and the plank edges were less vulnerable in beaching, but the clinker topsides were less work and cheaper and strong. Something similar could be done with strip planking and glued clinker ply.