Planning new pirogue

[jdupre']

It's been a year or two but it's time for another pirogue build. Initial thoughts are for an approx. 13ft fairly standard ply pirogue with a couple of new things. Y'all know I have to have new things! I'm thinking a verticle stern angle and a either rounded bow or more upright bow angle. In other words, I want a 14 ft. pirogue waterline with most of the dimensions of a 12 and 1/2 ft pirogue. Neat trick if I can make it happen.

Also, I've built enough boats to have a feel of how light I can go with the structure and still have a usable boat. Yes, the lighter you go the less strong it is. Got it. But less strong does not equate to weak. There is a gray area between the two that I want to explore. In my mind, a completely rigid boat with no give anywhere is overbuilt. Overbuilt by how much, I don't know, but I have a good idea. I'll explore that area. One way is another hybrid build: chine logs for 90 % of the length with stitch and glue for the stems and front and rear 12" or so. Less lumber, less epoxy. I'll only use epoxy and cloth where absolutely needed. Western red cedar for structural members. Sides as low as I dare. The Swamper had 6" sides and I never remember the water coming up on the tumblehomes. 7-8" seems about right.

This will be a flatwater boat. Very limited use on inland lakes and only in really calm conditions. I plan on a little fishing and short cruises. Looking for light weight. Closing in too fast on 70 and weight has become a consideration. Time to go scout around Lowe's and Home Depot.

 

[oldbuffpilot]

O Boy I can't wait to watch this, wish I could watch up close and learn direct fromm the master!
Your objectives are very close to my usual wish list. I am completely on board with your thoughts about weight and strong enough. I have to have some of each to be a usable boat for this 78 years of fishing experience, ie I'm not old just experrienced. It has been years since I built/used a boat with chine logs, maybe you could go Stitch and glue all the way, not advice just a suggestion.
Get in the truck and head to town for lumber!! I can't wait to watch.
.

 

[beekeeper]

Vertical or near vertical stems can increase the waterline length. I reduced the angle of the stems on my last build from "8 on 12"to "6 on 12". The floor is 11.5' for an overall boat length of 12.5'. I would guess many 14' boats may not have this much. Other than hopping over logs and/or gators near vertical ends should work OK. Canoes seem to be built that way.
Why the hybrid chine? Is the epoxy filet lighter than WRC? Does it require fiberglass cloth to be strong enough? I would think the cedar chine logs and stem pieces will not be a weight issue or a place to save significant weight.
I find it hard to build "light weight" using traditional methods because there is a lack of suitable (light) planking. Plywood is lighter than 3/4" cypress boards but it is still heaver than cedar sandwiched between fiberglass.
Building the boat as short as you can live with will help. There will be less material and it will seem lighter because it is easier to handle. A tumble home in the sides could add height and stiffness to the sides and may eliminate the need for gunnel strips.
Good luck with the lumber shopping. 1/4" pine plywood at H.D. today $39.95. 14'- 2"X4" white pine $19.95. Sorted thru a whole stack and found none suitable for chine logs. Noticed a (as in one) 1" X 12" - 10' cedar finger jointed board $56.

 

[jdupre']

Probably not any major savings in weight. Subtract 4 pieces of chine log about 18" long, two stem pieces, two cutwaters and the glue and fasteners to hold them. Add back 4 fillets 18" long, two fillets for the stems and a little glass reenforcement. Maybe a pound in savings. But, a pound is a pound.

One inch lower sides. 1" x 13' x 2 sides = 312 ". 312 divided by 144 sq. inches = 2.16 square feet. 2.16 square feet x .875 lbs (weight of pine ply per square ft) = 1.89 pounds. We're up to almost 3 lbs savings. I have other weight saving ideas rattling around in my head.

A 13 ft boat that has the waterline length of a 14 footer has the benefit of the longer waterline but without the extra foot of weight of the "middle" of the boat which is where most of the weight is concentrated.

Saving 3 or 4 pounds is maybe not beneficial in a practical sense, but is rewarding from a design aspect. Quoting one of my old archery books "Difficulties add zest to the project."

 

[jdupre']

Why the hybrid chine? Well, for simplicity and build speed. Chine logs equal not waiting endlessly for epoxy filets to cure, then sanding them, then covering with cloth, and sanding that, and fill coats of epoxy and MORE sanding. What little epoxy and glass I'll use can be done in a couple days not a couple of weeks. Chine logs go in, dry overnight and you're done. Way less fitting at the stems. You wire the front of the panels together and epoxy. A good, once around sanding and a couple of coats of paint. I'll use what I feel is the best in terms of build speed, build ease and durability.

Bee, your approach and mine are quite different. You favor the old school woodworking approach. Absolutely nothing wrong with that. My approach is mainly 3D sculpture. I want a certain shape and a certain look, all the while making sure the boat does it's job well. It does not matter how I achieve the shape. I admire the old school builders, but I have my "new school" ways.

 

[jdupre']

I was just thinking. I might be kicked out of the pirogue club. Verticle stern......nope. Near verticle bow......nope. Mix of modern and traditional......nope. Double paddle and foot pegs......nope. I'll just call it a flat bottomed paddle craft.

 

[oldsparkey]

Remember the saying , measure twice and cut one time. Well modify it to Think three times , worry twice and construct one time.
Personally I would use 1/8th inch door skins , epoxy saturate the whole boat and glass the whole thing with 3.25 tight woven glass. 14 feet in length it should be between 30 and 32 pounds when done. Even lighter if you use a drop in seat.
The epoxy saturated wood and thinner but tight woven glass lets the bottom have a degree of flex if you run onto a log or stump.

 

[jdupre']

Chuck, that would make a better boat, but I'm just not into the total fiberglass thing now. I want something a little simpler....and quicker.

 

[oldsparkey]

Chuck, that would make a better boat, but I'm just not into the total fiberglass thing now. I want something a little simpler....and quicker.

Might want to watch this but it does require some glass work. A good example of light weight construction and how the center material can be anything when using glass.
I found it quite interesting.

 

[beekeeper]

Bee, your approach and mine are quite different. You favor the old school woodworking approach. Absolutely nothing wrong with that. My approach is mainly 3D sculpture. I want a certain shape and a certain look, all the while making sure the boat does it's job well. It does not matter how I achieve the shape. I admire the old school builders, but I have my "new school" ways.

I do prefer working with wood. Every boat, and build method is a compromise and have their limitations. Your visions and approach may be different but our goal is basically the same, build a boat that meets our needs.
I now understand your reasons for the hybrid chine logs and stems. My main reason for traditional wood working builds is I don't care to mix methods. I see no need to buy epoxy and glass cloth just for the chines. I'm not sure trading chine logs for epoxy peanut butter and fiberglass will make a significant weight loss if you use pine plywood. Not much practical difference in 45 lb. vs 49 lbs. Probably have to go cedar or luan /fiberglass sides and bottom for much change.

 

[jdupre']

45 vs 49 lbs IS a worthy enough goal in itself from my design standpoint. I think I'll save at least a couple of pounds. Anyway, I'm doing it partly for the ease of building and a little more freedom in the stem shapes and ...........just because. If I was practical, I'd just go buy a second hand canoe on Craigslist and be done with it.

No stems, no cutwaters 4-5 feet less of chine material, glue and fasteners all add up Glass cloth to cover joints weighs almost nothing. The epoxy has a little weight to it. I already have some leftover cloth and epoxy I'll use up. Anyway, I'm playing with the houses money. The boats I've sold paid more than I had in them. I've had fun and made a bit of money. Fair enough.

 

[beekeeper]

I don't know if this will help or not. I weighed a cedar 2 X 4 today and it weighed 8.5 lbs. My rough calculations indicated the lightest weight traditional built chine logs and stem pieces would weigh 6.75 lbs. to 7 lbs. Pine batter boards (cutwaters) would add about 1.25 lbs.
If I understand your plans to cut weight, you will save about 2 to 3 lbs.
When I asked "Why the hybrid chine?" I thought your goal was to build a "light weight" boat not just a lighter boat. Your ideas should work.

 

[jdupre']

Thanks for the weight info. LightER is what I want. Wanting a LIGHT boat, I would never start with two 25 + or - lbs sheets of plywood. It's mostly an itch I want to scratch. Minimizing (not eliminating ) glass and epoxy is my goal. Epoxy is some amazing stuff if used judiciously. 2 -3 lb weight reduction along with an easier build would be great for me. I have a couple of other weight reduction things I want to try also.

 

[mike]

Might want to watch this but it does require some glass work. A good example of light weight construction and how the center material can be anything when using glass.
I found it quite interesting.

That is an interesting boat and build. Very different, for sure. Thanks!

 

[beekeeper]

I had another thought about your plan for near vertical stems. As discussed before angled ones would work better for waves, going over objects and beaching the boat. for paddling only the part of the floor in the water matters. Rocker and/or trim should keep the stem up some to prevent possible collisions with submerged objects but not so much as to increase drag.
Rounding the stem over some like your last build should let you get by with a near vertical stems. That will give you the most water line per overall boat length. Compromising is so much fun isn't it.

 

[jdupre']

Bee, that's one of the reasons for using stitch and glue for the stems.......more flexibility where the bottom and stem meet. I'll be going with very little rocker so a little slope at the lower bow will help going over logs and such. Like it's been said, every boat is a compromise.

 

[oldbuffpilot]

I’m still lurking out here watching and learning. A few days ago I typed some thoughts and questions, and lost them in the draft feature. I'm sure I selected the wrong key or something. So I’ll try again.

Stem angle: I never considered, we could increase stability by a more vertical stem. I thought I had figured out working with models that the stem angle mostly affected flare, the more vertical the stem, flare decreases ?? So more things to think about.

I suspect Bee is right about the weight of cedar chine logs vs fillets. On a few of the 4 H boats we used bottom/side S & G fillets with one step and one day to cure. We put the fillet in, then the cloth while the fillet was still wet. Then the next day glassed the outside of the seam. Still longer and more complicated for kids.
I have found that the slotted(box beam) gunnels can be lighter and stronger than larger solid ones. There again it is more complicated and time consuming.
JDupre made me grin because simple and quick builds is what drew me to this forum! Guess I got sucked in and carried away! The three “17 lb “ pirogues we built were an attempt at a simple and quick build. The one with a cedar floor is still in use, so maybe it worked after all. I have quit using batter boards on the stems and so far haven’t had any damage.

Looking forward to more on this build concept.

 

[beekeeper]

I think we are talking about "deadwood" http://www.greenval.com/shape_parthtml1. at the bow. Not sure if any is needed at the sterrn.
Stitch and glue should make it easier to shape.
Any boat with its bow not submerged has some. Too much and the water line is shortened and has a wider entry profile. Here we go compromising again.

 

[jdupre']

I doubt the finer intricacies of bow shape and stem angle make a heck of a lot of difference. Mostly, though, waterline length along with the width dictates the speed of the boat. There's really nothing you can do to 12-13 ft boat to make it the equal of a decent 16 footer.

Bee, i think the deadwood is actually the excess bow and stern hull that rides below the waterline. Too much is not good. Still, I don't think that makes a big difference in a 12-13 ft pirogue.

 

[beekeeper]

I agree that none of the features we are talking about makes much difference overall. The sum of all these changes could make a better boat depending on your goals.
Only two of my builds have been a disappointment to me performance wise. My first was too wide, too heavy and way too much rocker for paddling. The other was my little river punt, too short, and too little rocker. All the others were quite suitable for my use and there seemed to be little practical difference in their paddling.
The longer boats were somewhat easier to paddle (faster).

Andy, we have all been sucked in and carried away, isn't it fun? You mentioned "the more vertical the stem, flare decreases??" I would agree. The side flare will decrease slightly because the gunnels would be pulled together sooner, unless you made the stem wider at the top, or used oversize breast-hooks to spread them apart.