Barge > Scow > Punt. Ya, that sounds better. IMHO.

 
weedeater64
 
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weedeater64
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04 September 2013 20:04
 

So anyway about 10 years back I fancied the idea of building a sailboat and sailing around the world.
Then reality and life set in, and I never got past the cheap canoe.

I built it with cheap home depot (bc, I think) plywood and their eight foot 1x1’s.  I used pl premium and drywall screws. I covered screws and filled gaps with durams water putty and hurredly slapped on two coats of cheap latex.

I didn’t leak at all, at all. It sat out on the ground for three years, often right side up, and still didn’t leak, but was beggining to rot.

Anyway, I’m ready to have another go. I live in Arkansas and enjoy fishing. With age I don’t much enjoy walking the banks and getting chigger bit and all that.

I initially was thinking of an ozark float boat, something like this, then I was thinking more like a thames punt with a curved rocker instead of the angled one on that boat.

Then I started thinking about multies again, and remembered this.

Then began thinking outrigger, to save money, that led to proas. I have Gary’s book, and considered the Wa ‘Apa. Then I stumbled on the Mary & Lamb article at duckworks and a day or two later found Johannes post here about the barge proa.

I like it, and am seriously thinking of building one.

I will not be using epoxy and fiberglass. Period.

So instead of plywood (haven’t ruled it out though) I was thinking of using sawn lumber. I went to the local lumber yard and had a look to see what they had. Red Cedar at 40 bucks for 1x12x16 is more than I want to spend at this time. The have what they are calling ‘Southern Yellow Pine’ for 17 bucks for 1x12x16. I’ve noted reading on the wooden boat forum that ‘Southern Yellow Pine’ doesn’t mean what it used to, but I’m still thinking of using it throughout, or maybe using poplar or something for chines and such.

I’d sorta like to go 16’ for transport and budget reasons, but it wouldn’t take much to convince me to go 20’ for the performance.

I can not decide on a beam width. 24”, 20”, 12”...??.. What do you guys think?

Also, would it be ill advised to just use 12” boards for sides and bottom? Or should I use smaller widths?

Also I was thinking of caulking cotton twine, cement and roofing tar.. Someone at boatdesign forums suggested just using some waterproof construction adheasive caulk. I like the idea of using something easy, but I’ve seen more than one person warn against using adhesive, and stick to caulking. Also I’ve seen the post around the net talking about pl premium and as I said, had good luck with it myself. However, going to their website, the don’t recommend any of their products for under water.

Without ordering, is there any hardware store product you guys would recommend for sealing seams that is easy to use?

And if using say pine boards for the sides, and plywood for the bottome, how whould you seal the plywood, other than with epoxy?

[ Edited: 04 September 2013 21:07 by weedeater64]
 
Editor
 
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Editor
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04 September 2013 20:47
 

I fixed a link in this post. Please carry on.

 
 
weedeater64
 
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04 September 2013 21:06
 

Thank you Editor.

 
Johannes
 
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04 September 2013 22:39
 

If you don´t like working with epoxy and fiberglass you could always glue any joints with polyurethane.

Casco Polyurethane

Titebond Polyurethane glue

They are strong and mildly gapfilling. You need to have large areas without gaps, but some small gaps does not effect the total strength much.

If you want a lot of good information about building barges without epoxy you should read about Triloboats.
http://www.triloboats.com
Building Slacktide

Cheers,
Johannes

 
 
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05 September 2013 05:26
 

I’d sorta like to go 16’ for transport and budget reasons, but it wouldn’t take much to convince me to go 20’ for the performance.

If it is going to be used as a stable fishing platform I would go with a 16 foot long and 20 x 20 inch hull width and height. If you want good sailing performance longer and more slender is the way to go.
I want to build a 24 foot long, 24 inch wide and 24 inch high main hull. I would build it out of 3/4 inch plywood (one inch bottom) for durability. I tend to use my boats hard and without much care, and I want them to take it without any problem. I grew up with a heavy steel tug, and I put a lot of dents in a lot of rocks and stuff.

Cheers,
Johannes

 
 
old greg
 
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05 September 2013 15:34
 
weedeater64 - 04 September 2013 08:04 PM

So instead of plywood (haven’t ruled it out though) I was thinking of using sawn lumber.

Is part of your reluctance to use plywood due to the rot in your previous boat? Because, I think a large part of the problem was the quality of wood you used.  Normal exterior grade plywood is full of voids that will collect moisture over time and cause the wood to rot from the inside out.  Marine grade plywood will last a lot longer.

weedeater64 - 04 September 2013 08:04 PM

I can not decide on a beam width. 24”, 20”, 12”...??.. What do you guys think?

How much stuff do you want to carry? and how shallow do you need the draft to be?

With the outrigger, the beam of the main hull doesn’t really contribute to stability, so with the length constrained to 16’ (or maybe 20’) and the draft probably constrained by how/where you plan on using the boat, the beam becomes a simple trade off between lightly loaded speed and load carrying capacity.  All things being equal, a narrower beam will make for a faster boat when it’s lightly loaded, but when you start piling on the weight (a buddy or two and a couple of coolers full of ice for beer/fish) it’s going to lose more performance than a wider hull would.

weedeater64 - 04 September 2013 08:04 PM

Also, would it be ill advised to just use 12” boards for sides and bottom? Or should I use smaller widths?

If you’re going for a three sided hull, and you can get enough clear, straight grained planks that wide, I don’t see any reason why not.  And on the plus side, wider planks means fewer seams to worry about.

weedeater64 - 04 September 2013 08:04 PM

I’ve seen the post around the net talking about pl premium and as I said, had good luck with it myself. However, going to their website, the don’t recommend any of their products for under water.
...
And if using say pine boards for the sides, and plywood for the bottome, how whould you seal the plywood, other than with epoxy?

When they say “underwater” they mean 24/7/365 for years at a time.  It’s the same for boat paints that are “not for use below the waterline”.  For a boat that will spend most of it’s life high and dry, it’s not really a concern.

I say go with the PL construction adhesive (which is basically the same as the stuff Johannes linked to) to seal up the joints with screws or ring shank nails to actually hold the boat together, and for sealing plywood just use an oil based paint and touch up as necessary.  If you’re concerned about wear and tear from rocks and what-not, several layers of a polyurethane floor/deck paint should be a lot tougher than the latex paint you used in the past.

 
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05 September 2013 17:15
 
weedeater64 - 04 September 2013 08:04 PM

Anyway, I’m ready to have another go. I live in Arkansas and enjoy fishing. With age I don’t much enjoy walking the banks and getting chigger bit and all that.

I can not decide on a beam width. 24”, 20”, 12”...??.. What do you guys think?

Also, would it be ill advised to just use 12” boards for sides and bottom? Or should I use smaller widths?

Also I was thinking of caulking cotton twine, cement and roofing tar.. Someone at boatdesign forums suggested just using some waterproof construction adheasive caulk. I like the idea of using something easy, but I’ve seen more than one person warn against using adhesive, and stick to caulking. Also I’ve seen the post around the net talking about pl premium and as I said, had good luck with it myself. However, going to their website, the don’t recommend any of their products for under water.

What part of Arkansas? My last boating for a while was on the Beautiful Buffalo, Pruitt to Buffalo Point.
Built my first canoe in Fort Smith some 54 years ago.

I think you need to consider how the boat is going to be used, stay in the water most of the time, or trailered (don’t think with construction envisioned you’re going to cartop it).

Width of the hull probably needs to be a balance between displacement, draft and width. Say 400# on a 16’ slab sided hull with a PC of around .75 is going to require a midsection area of just over half a square foot (.53). 6” draft by 12” beam would work but I’d lean towards a 16” wide hull. Unless you’re planning on fishing a lot of shallows, then wider would be better.

By all means use PL Premium, its the go to stuff for cheap easy boat building.

How are you going to move around? pole, paddle, trolling motor.

I can see the boat drifting down the creek feet in the hull, cut down lawn chair between the hulls; shunt to fish the other bank.

Best Wishes,
Skip

 
weedeater64
 
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06 September 2013 18:45
 

If it is going to be used as a stable fishing platform I would go with a 16 foot long and 20 x 20 inch hull width and height. If you want good sailing performance longer and more slender is the way to go.

I suppose fishing platform and sailing performance are of equal value to me. I’m drawn to multi’s because of the easily driven hulls, as well as the vast deck space compared to monos. I’m actully sort of leaning back toward a cat. I am planning to build an outrigger/proa first, and possible build another main hull later.

BTW, what is the difference between a proa and an outrigger? I realize a proa is an outrigger, but other than it only having one ama, is it the shunting that defines a proa?

20 inches is a bit high for sides I think. I think I’ll start with 12 and add a strake later if need be.

I don’t know what I was thinking with the question about widths, ie.. 12”. Of course won’t do, it wouldn’t have nearly the carrying capacity I desire. I want to carry at least two people (my self and another), I’d prefer more, but limitations at this time I think will prevent that.

I’ll probably start with 16’, well 15.5 or something by the time I bend the bottom..

Is part of your reluctance to use plywood due to the rot in your previous boat? Because, I think a large part of the problem was the quality of wood you used.  Normal exterior grade plywood is full of voids that will collect moisture over time and cause the wood to rot from the inside out.  Marine grade plywood will last a lot longer.

No, it’s more just wanting to use real wood. I’m sure I’d have gotten more milege out of that boat with a better paint job initially, and a bit of maintenance. If I was going to fork over the ridiculous price for marine ply, I’d much prefer to go ahead and get some quality lumber. I have no doubt marine ply is better than lumber yard stuff, but it is still just plywood. Can not compare to real wood on any level.

How much stuff do you want to carry? and how shallow do you need the draft to be?

I had considered this, but when I made my opening post my mind was scattered a bit. Wider is definitely going to be better for me, as I do plan to carry at least one person. Though I may build a second main hull later and make a cat. IDK yet. So, 12” is out for sure. If I do use ply, probably go with a 19” bottom for best use of material with 14” sides, possibly a bit wider and shorter..

If you’re going for a three sided hull, and you can get enough clear, straight grained planks that wide, I don’t see any reason why not.  And on the plus side, wider planks means fewer seams to worry about.

My concern is swelling/shrinkage of planks, especially since boat will be in and out of water. I’m not concerned about using 12” side planks, but the bottom. 6” is , I believe the max. generally recommended for planking.

I think I will use PL for adheasive. Still not sure what I’ll do about seam sealing though, if using sawn timber.

What part of Arkansas?

I’m in Conway. Primary usage will be in Lake Conway , Palarm Creek, Arkansas River, Cadron Creek.

don’t think with construction envisioned you’re going to cartop it)

For a while it will be. I do plan to build a trailer though.

I’m thinking 18” minimum now.

How are you going to move around? pole, paddle, trolling motor.

Pole, paddle and sail. I don’t plan on a motor, but who knows…

 

 

 
old greg
 
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08 September 2013 09:48
 
weedeater64 - 06 September 2013 06:45 PM

I’m actully sort of leaning back toward a cat. I am planning to build an outrigger/proa first, and possible build another main hull later.

BTW, what is the difference between a proa and an outrigger? I realize a proa is an outrigger, but other than it only having one ama, is it the shunting that defines a proa?

That’s how I define them personally: a proa is an outrigger that shunts.

Since you’re thinking about turning it into a catamaran later, you’d probably be better off building a tacking outrigger.  It will make the rigging, rudders and boards a lot simpler and it will allow the main hull to be better suited to it’s eventual role as half of a cat.

weedeater64 - 06 September 2013 06:45 PM

20 inches is a bit high for sides I think. I think I’ll start with 12 and add a strake later if need be.

You know your waters a lot better than any of us do, so maybe that will be enough for your needs.  Just remember though, with a narrow hull it won’t take a whole lot of extra weight to make you wish you had more freeboard. 😉

weedeater64 - 06 September 2013 06:45 PM

I don’t know what I was thinking with the question about widths, ie.. 12”. Of course won’t do, it wouldn’t have nearly the carrying capacity I desire. I want to carry at least two people (my self and another), I’d prefer more, but limitations at this time I think will prevent that.

I’ll probably start with 16’, well 15.5 or something by the time I bend the bottom…

Wider is definitely going to be better for me, as I do plan to carry at least one person. Though I may build a second main hull later and make a cat. IDK yet. So, 12” is out for sure. If I do use ply, probably go with a 19” bottom for best use of material with 14” sides, possibly a bit wider and shorter..

I think an 18’ x 16” hull will work out well for two people. With a Cp of 0.75 you’d have ~6” of draft with 550lbs of displacement.  And if/when you add that second hull you’d have plenty of people carrying ability.

weedeater64 - 06 September 2013 06:45 PM

I think I will use PL for adheasive. Still not sure what I’ll do about seam sealing though, if using sawn timber.

PL will be fine for sealing seams as well.

 
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15 September 2013 18:09
 
old greg - 08 September 2013 09:48 AM

Since you’re thinking about turning it into a catamaran later, you’d probably be better off building a tacking outrigger.  It will make the rigging, rudders and boards a lot simpler and it will allow the main hull to be better suited to it’s eventual role as half of a cat.

 

Hmm, is there any reason I could not sail a cat as a shunting vessel? I really like the crabclaw rig, as it seems simple and easy to construct. It is a big part of what I find appealing about proas.

 
old greg
 
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15 September 2013 21:41
 

Nope, no reason at all.  But there’s also no reason why you need to shunt to use a crab claw sail.

 
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18 September 2013 09:06
 

This is a german documentary about the Lapita Voyage, an expedition which aimed to show that Polynesia could be settled from Asia with the technology available at the time. James Wharram designed the crab claw ketch-rigged catamarans they use for the expedition, which were built with the technology available to the ancient asians / polynesians. I thought it was a pretty interesting documentary, but even for non-german speakers skipping through and having a look at some of the footage is probably worthwhile too. 😊

http://www.zdf.de/ZDFmediathek#/beitrag/video/1126550/Wagnis-in-der-Südsee

Just like greg said, cats with crab-claws work fine.