PVC pipe as a SOF kayak frame material?

I am dumfounded how you continue to say plastic pipe is cheap and easy and that wood is hard and expensive -it is the opposite. Is $200 in materials for a 14-16ft kayak expensive? You don't need cheap wood, you need a little bit of good (right) wood. Find a 16ft piece of wood with straight grain an no knots and the store will even rip it down to your desired strips. You even have the design in the form of a physical example. You might even rebuild the SOF boat you have fixing the parts you don't like. I don't understand your recue issue -in the beginning, all kayaks were skin on frame. The traditional build is as strong and resilient as anything. There was a guy on these forums "Petro" that would build SOF boats out of any leftover wood he had -to de-stress. If you weren't so insistent on "cheap" I am sure there are similar artisans around that would make you the kayak you desire cheaper than production plastic.

 

Mitch,

You want to do this no matter what is said.
Just do it.
You can use saran wrap to make a temporary skin to see how the flexible boat feels.
It won't last long (minutes) before it takes on water.
But you can wrap it multiple times if you need more time without a lot of expense.
I hope we seen one within a week.
Seriously.

 

I didn't say wood was expensive. It is somewhat more expensive and harder to use than plastic pipe - the frame could have been cut and put together in maybe 30-60 minutes, and would have been easy to modify. My original 1/2" PVC concept, which I have had to reject due to poor durability, would have cost maybe $30-$50 for the frame.

There does not seem to be a "Petro" member of this forum. Nor have I so far managed to find anyone who makes them for a fee, except some distant shops that charge $3000 - $4000. There are some places that offer classes in SOF building, for about $1500 on up,- but from what I have found so far, they aren't custom boats - just boats that are too big and too hard to lean for me - and they don't complete the boat during the course - you have to take it home and complete it.

There is a marine museum within a couple hours of where I live that has an "Apprentice for a day" program in large wooden boat building - but they are different types of boats, and it would take a lot of time to learn what they teach. I tried that program for a few weekends. They taught me how to use and sharpen a plane, and how to cut with a specific type of Japanese saw, how to feed a plank through a very expensive planar the size of a small room, and how to use a hole saw to make wooden pegs, and pound them into holes. Likewise, a club I belong to taught us how to make a crude Greenland paddle, also using a plane. They offer another workshop to make a neoprene spray skirt. But these aren't skills that allow me to make a complete SOF boat. I guess it is assumed that all wood-be boat builders already understand the basics of working with wood. I have found books on woodworking - but they are dealing with fine points, like how to measure the water content of wood, the properties of specific types of wood, etc., not the basics. They also assume you will create a large home shop with a few thousand dollars of tools.

No store in my geographic area that I have found will rip thin wood strips (they say it is too dangerous), nor do they stock 16' boards. Maybe I just don't know where to look. I just bought myself a circular saw ($8 used), and I also have a jig saw ($5 used) - I may be able to figure out how to use them, though the circular saw looks scary.

I want to try first with cheap wood, and cheap cloth (e.g., painted canvas), because I suspect I will mess up the first time.

 

Unlike you.
The schools know that it will take years of practice to learn the skills used in woid boat building.

 

There have been guys who cut the frame strips with either a skill saw or a jig saw. 3/4 x 3/4.
The bulkheads can be cut with the jig saw. 1/2 ply.
Frame strips can be and usually are spliced. The jig saw or a japanese hand saw works fine. Home Depot or Lowes 8' lumber (and not much).
My first boat was Dyson supplied polyester cloth. Worked just fine.

You are making too many excuses.
The biggest attraction of SOF is that you can do one with minimal tools.

You can either start somewhere or just keep talking.

 

Petros | Boat Design Net

He hasn't been around in a few years. He proposed a hardware store sailboat race class (a good thread to read) and I recall he frequently talked about making SOF prototypes like you are considering. He used canvas and old latex paint and reported 5yr+ life.

I will look through my old links -I recall there was one dominant source for SOF kits that was not cheap. Home depot used to cut wood on a table saw on request. A circular saw with a guide can rip the stringers but the right tool is a table saw.

The rare tool is the steaming box but you can make your own.

 

Cape Falcon Kayak (thinkific.com)
How a Modern Skin-on-Frame Kayak is Built | Seawolf Kayak
Workshop Tools: The Annotated List | Seawolf Kayak
Skin-on-Frame Custom Kayak - Intro (lightweightboatbuilding.com)

There seem to be lots of "modern SOF" construction plans that use plywood frames -I am not a fan but if you still plan to make a folder in the future I guess this would be good experience.
(2040) How to build a Kudzu Craft boat - YouTube
gentrycustomboats.com/Planspage.html
skin boat fabric (skinboats.com)

 

Great info, everyone.

I'm trying contact Petros through this board.

A person I know who used to build also recommended Brian Schulz at Cape Falcon Kayak, and suggested the F1 model. Not cheap, for the boats, kits, or shipping. But at the least, I will look at the free video classes.

Cape Falcon's videos show putting together pieces using a combination of stitch and glue, mortice (a new concept to me), and lashing. I'm trying to understand why lashing is used.

Skin on frame boat building. Kayak and Ultralight boatbuilding https://www.christinedemerchant.com/boat-styles-skin-on-frame.html says

Is lashing still the best and easiest way to build SOFs with modern tools, materials and techniques?

My Home Depot and Lowes said cutting thin strips is too dangerous on their saws, and they don't sell 16' boards. But Cayuga Lumber in Ithaca, NY, near where I sometimes visit, says they might do it - at about $1/cut, and they sell 16' boards, though only in a few woods.

 

https://www.homedepot.com/p/2-in-x-...-Southern-Yellow-Pine-Lumber-581968/202085928
https://www.homedepot.com/p/Weather...Pine-Pressure-Treated-Lumber-253921/206967797

 

Ergh... Hope this thread is not too old to get resurrected.

Well, if PVC is not good for framing, what about polypropylene then? Specifically - multilayer PPR pipes, which have AL- or fiberglass- reinforced middle layer?

 

Polypropylene stiffness is even lower. Framing needs to be light, stiff and tough. Wood is the best materials for the cost. Other materials that are competitive with wood are expensive.

 

Aluminum is perfectly capable and is commonly used for kayaks that can be disassembled for transport. Nobody does it but you can use both wood and aluminum to make things easier.

 

Think global
Proper wood, especially of fine quality, in right sizes etc. is expensive in some regions, or even impossible to find, especially in quantities needed for a single home-built boat.

E.g., for me it's hard to find anything except 12ft long pine or oak in local stores or nearby mill yards (from the stock). Spruce or ash is something that should be ordered in advance, and then additional time to dry it properly, and min. order would be enough to build few dozens of kayaks etc., etc.

That's why people may want to use some alternative, widely available materials.

 

I am thinking global. Unless you live in the Artic, there will be some local wood available. There is no need to get "fine quality" (furniture grade) lumber for a SOF. Pine or spruce works fine. All you have to do is go through the wood pile and find a couple of better boards. If you can't splice two 12 foot pieces of wood to make a longer one, there are millions of articles and youtube videos on how to do it. They vary from scarfing to lashing. People have been building boats with locally available materials for thousands of years. In fact, SOF boats derived from the lack of availability of large pieces of lumber. Kayaks were built with driftwood.

 

And sometimes at least partly from bone, along with animal skins and ligaments. They used whatever they could find. I wonder if you worked hard enough at it, bone could completely replace wood. AFAICT, bone tends to fracture if you bend it much, so maybe not, or maybe it would depend on conditions.

However, some of us view SOFs as a fairly easy way to get a lightweight boat. For that purpose, high grade wood is presumably better - because the pieces can be thinner. I.E., knots reduce the strength of the material.

I've recently looked around a little more, in more stores. 16' wood is moderately common, if you know where to look. It is mostly an unspecified "white wood" - e.g., pine, spruce, or birch. I'm not knowledgeable to tell the difference. But there is specifically labelled high grade (mostly knot free) pine, including in 16' lengths. Most commercially made sea kayaks are longer, for speed - but that may be partly because most such sea kayaks do not have close to full length waterlines, but more or less follow the Greenland model. (Or maybe stem plates could be used to make the boat slightly longer.) Hopefully, pine is good enough...

Some lumber stores give away scrap wood, or sell it very cheap. Likewise with palettes. By the time you spliced it together, I'm sure the the result would be substantially heavier than if you start with high grade wood, and would take more time to build. But I bet some of the original arctic kayak builders, some of whom lived rather close to the edge of survival, and who made due with driftwood and bone, would have been happy to have it.

In any event, I have to move, so have put this project on hold for now. Perhaps the new place will be easier to build from. Or I might visit my relative's place in NY state, that has a big yard, when the weather is warmer.

While moving, I put some stuff in a rented 10'x20' drive-up storage unit. I saw one person there who had rented a storage unit which he used as a crude woodshop, working with the door open in external sunlight. He used battery powered tools, and also had a small generator. I guess I could build a boat inside my unit, if I leave enough space. Of course, rented storage units cost money, and I'd have to visit fast food places to use a rest room. But it's an idea. I think the only battery powered tools I would need would be a jig saw and a drill (and they don't need to be heavy duty construction grade tools), so I wouldn't need a generator. I'd need a tarp, so paint and glue wouldn't mess up the floor. Perhaps I should ask management's permission.