help lightest boat you can build

[Kayak Jack]

Ronnie, we may not be nearly as far apart as you thought we were. While even you said that you built the boat out of too thin of wood, it's lasting for you. As I remember, you were patching and reinforcing some areas.

I'd like to see your stripper. Maybe I can get you to bring it up to paddle some Michigan rivers. Next week, we're gathering paddlers from Michigan, Wisconsin, New York, Florida, and California to paddle the Manistee River for a week. Clear water, no snakes, (and, most importantly) no inadvertent dam releases.

 

[oldsparkey]

I cant stand it. :twisted:
Jack talks about the good wood in his yak being supreour ,but on our trip I was in a boat built from 3/16 laun bottom and 1/8 sides and deck painted bottom out of poly . Looking at the boats at the end of the run there was very little difference in the shape of the bottoms. Mine made it just fine. Well I have to admit I didnt hang up on as many rocks as Jack did. :lol: :lol: :lol:

Ron

Ron .....

You have to remember , making boats out of the inferior wood ( Jacks term for it , not mine ) is not Jack's style.

Now , when a person makes more then one or two boats we tend to cut back on the cost of the wood and make a really serviceable boat at a lower cost which is the main idea of making your own boat. YES, I have made boats out of the expensive wood ( two of them ) and the rest ( 9 of them) of them out of the $9.95 a sheet Luann and for the sake of me I do not see any difference in them. They all float , take my gear and me and even bring me back after the trip.

RON..........
Now I would suggest you take Jack up on his trip idea .... You would love that wilderness. If anything Jack might civilize your style of camping and you could toss your lantern in the garbage.
Besides you are the only one formally invited ( or told about it ) to go on the trip in this open forum.

Chuck........
PS.. I have not had to patch a single one of my inferior wood boats. I don't paddle down rivers that are all rocks like Ron does. But when I did....... I do know my 1/8th inch wood canoe came out of that last trip with less scratches ( very few light ones ) then a store bought canoe that was there did.

 

[Wannabe]

Ron .....

You have to remember , making boats out of the inferior wood ( Jacks term for it , not mine ) is not Jack's style.

And thats fine. He even drinks single malt Scotch. That is fine too, I just can't understand whe he doesn't mix it with grapejuice. :mrgreen:
Bob

 

[Ozark]

It will be good to see how the scoring will be done.
On a scale of 1-10, 1-100,
40% serviceability = .4 x your score
60% weight =.6 x your score
yep will be interesting to see the rules

 

[jdupre']

If balsa-cored panels can hold up to 1500 hp racing boats in 6-8' seas ( which they obviously can) , there is no way they could be even remotely considered weak or inferior. Now, would top quality ply cored panels be stronger? Maybe yes, but at the expense of weight. Balsa cored panels may indeed be" weak-ER" but that doesn't equate with being "weak".

The truth is, a durable paddle craft should be made of 1/2" ply containing the best exotic woods on the planet, laminated with state of the art ( VERY expensive ) adhesives and covered with 16oz. kevlar or carbon fiber and $200.00 a gallon epoxy. Anything less makes for a weaker boat. Oh, you want a cheaper, lighter boat? You will have to give up strength and durability. THAT'S where the boatbuilder must make an executive decision as to how weak a boat he can make and still be usable in the manner he wants to use it. That, friends , is the Holy Grail.

In the end, you can't argue with success. If you build a boat out of Ritz crackers and it lasts 20 years and never breaks, then Ritz crackers will make a servicible boat, no matter what the "specs" say.

Getting off the soap box now and going back to my cave.

Joey

 

[tx river rat]

Jack
Is right I had to patch my boat a few weeks before the trip. I was in a rapid going about 20 miles an hour hit a rock so hard it nearly thrue me out of the boat. I went on down river and fished all day paddled back up and when loading the boat noticed I had a fracture on the outside glass and cracked the wood. Boat didnt leak with all day of paddling. I bet the dollar sign on the wood wouldnt have fased the rock :lol: .
If yall remember thats when I said no more 1/8 wood I use them to hard.
JD is dead on a steel hull would outdo any wood hull , so its all location sensitive ,meaning what ever floats your boat. :lol: :lol: :lol: :lol:
Oh bye the way I dont use ply anymore!!!!!!
Ron

 

[seedtick]

This thread has been all overthe world with 5 pages of ideas, guesses, opinions and innuendo

But can anybody verifyably - if that's a word - beat Beekeeper's post of a 12 lb boat?

 

[Bellybuster]

I think thwe most interesting particle of that 12lbs boat is the fact that the builder used it for several years and then sold it to another fella that has been using it since. He admittedly states the boat is prone to "denting" but any boat you build can only safely be used to its limits. Go outside those limits and you're lookin for trouble.
It goes without saying that weight reduction comes at a cost, no matter how you look at it. To get the ultimate light weight boat the cost will be high, usually in the realm of durability and longevity.
For the sake of a competition, the cost can remain high for the duration of the competition and then minimised afterwards at the cost of weight by increasing the protective layers of glass or whatever coating you dicide, giving you a useable, durable boat that will last as long as those limits are not abused.
Lets not forget also that a super light boat is going to be expensive so that measure has to be in the mix as well. Light weight materials are expensive, at least the core material is. The light weight cloth is cheaper and uses less epoxy so the extra cost of the core material might be offset...who knows.

Another thought....maybe the whole sandwiched core idea is the wrong direction all together. Skin on frame has been mentioned. There is also the idea of building a wooden boat with no epoxy/glass at all. I grew up fishing out of a plywood motor boat that had no glass. It was nailed together and painted. We had that boat for ever (don't know what ever happened to it)
A S&G kayak minus the epoxy and glass would be super light and would easily last the duration of a competition to be glassed later. I could envision a kayak built with traditional S&G techniques right up to the point of glassing. It would definately float for the duration of the competition.
I have way too much time on my hands

 

[graybeard]

This thread has been all overthe world with 5 pages of ideas, guesses, opinions and innuendo

But can anybody verifyably - if that's a word - beat Beekeeper's post of a 12 lb boat?

The 12 lb balsa canoe is the lightest wooden boat I've heard of.

In other materials, you'd be hard to beat Geodesic Airolite Boats - 8lbs. Wood frame, kevlar roving, and heat-shrink dacron skin.

http://www.gaboats.com/

 

[Jimmy W]

Ancient Kayaker showed us a couple of years ago his 12 foot canoe.

Marine ply, cdn$100 to build, 22 lb all up including the fancy seat, no glass and very little epoxy (just used for one seam). One advantage of a very light boat is, you can treat it carefully, I just tuck her under me arm.

 

[tx river rat]

In the 12 and 16 ft class no skin on frame boats.
I think without breaking the bank you can build a pretty serviceable boat at 20 lbs.
Thats what this little contest is all about,finding the sweet spot ,getting reasonable longevity and service from a light hull.
I think it will be a balancing act
Ron

 

[graybeard]

I guess the next question would be what other items can you omit or lighten?

Use dowels for the breasthooks.
Sit on the bottom or use a pair of canvas slings for a seat and backrest (for the contest, anyway)
Leave out the inwales
Use split PVC for the outwales / gunwales (Would it be lighter than wood?)

Designer Colin Chapman designer of many of the classic Lotus sports and race cars had two aphorisms:

To get speed, simplify and add lightness.

Adding power makes you faster on the straights. Subtracting weight makes you faster everywhere.

 

[tx river rat]

Greybeard
No plastics just wood and fiberglass allowed
The seat will be a mini cell piece of foam carved to fit my rear and as thin as possible,no back rest.about the same set up the racers use ,very light and simple, Probably Black dog foot rest.
Ron

 

[jdupre']

Ron, I don't think you could go wrong with the same design/construction as the Duck. Cut away everything you dare above the waterline. Decks LOW and flat. 1/8" thick or less strips on the bottom and as thin as you dare for the decks. 1 oz glass with 1 total coat of epoxy with the glass on the inside. Epoxy on outside just enough to stick the glass down and to make the hull smooth below the waterline. 1" webbing glued in from side to side as a foot brace. 3/8" x 3/8" coaming trim. As Bellybuster suggested earlier, you could always beef up the strength later if you choose.

Psssst, Ron, you could put a tiny spray tip injecting dish liquid into the water right at water level at the leading edge of the bow. You didn't hear it from me. :wink:
Joey

 

[oldsparkey]

Psssst, Ron, you could put a tiny spray tip injecting dish liquid into the water right at water level at the leading edge of the bow. You didn't hear it from me. :wink:
Joey

Biodegradable , I would hope.

 

[jdupre']

Psssst, Ron, you could put a tiny spray tip injecting dish liquid into the water right at water level at the leading edge of the bow. You didn't hear it from me. :wink:
Joey

Biodegradable , I would hope.

Of course.

 

[tx river rat]

Jd
Just happen to have one of those sitting on y airboat :lol: :lol:
Ron

 

[jdupre']

One step ahead of me, buddy. I like that. :mrgreen:

 

[Jimmy W]

Designer Colin Chapman designer of many of the classic Lotus sports and race cars had two aphorisms:

To get speed, simplify and add lightness.

Adding power makes you faster on the straights. Subtracting weight makes you faster everywhere.

Greybeard, I thought about Colin the other day myself. I once read that he said that the perfect race car should be built just strong enough to get to the finish line in one piece and then fall apart after it crossed the line. Excess strength = excess weight.
Many of his innovations are still in use today; composite monocoque unibodies, aerodymamics, ground effects, active suspensions, use of engine and transmission as stressed members of the chassis.

 

[JEM]

I think the contest intent is for lightest boat you can build with common building materials and still have a functional boat for long term general use. If it's for the fishing crowd in Texas waters, my OPINION is skin-on-frame is out and gaboats are out... too specialized use. Plywood, woodstrip, or some combination are in.

If going with 1/8" [3mm] ply, then multi-chine with a rounded shape is going to get you the best structural strength-for-weight ratio. Rounded may not be practical for the fishing crowd. In which case, a flatish bottom with some additional framing or glass in that area.

If wood strip, going with less than 3/16" thick strips will require the same additional reinforcement on the lower hull and I'd be worried a little about the upper hull depending on how narrow a person went. 5/32" maybe, 1/8" woodstrips would likely bow when strapping down to the roof racks. I'd be worried that 1/8" strips would droop during construction as well if you use standard 12" mold/frame/station spacing.

Does ease of build get factored into the rules?