pirogue X two

[captaindoug]

I was wondering, Seedtick mentioned the fact the rocker in the stern will be less than the bow because the stern isn't being pinched in as severely with a square stern. If I were to put more angle on the transom than the ribs, would that get some of that rocker back?

Is that even that important? I was concerned about the drag caused by the square stern, thinking the rocker might keep the transom up higher in the water, causing less turbulence as the boat passes through the water. Of course everything is a compromise, by making the transom pinched more I lose some of buoyancy I squared the stern for in the first place. Any thoughts or comments about this?

 

[seedtick]

a narrower transom and more flare to the sides will increase the rocker, but now you're venturing into the design stage, which isn't bad at all, you just have to tread lightly and deliberately or you'll end up building more boats.

If i were you, i'd build myself a couple of jigs, plan on putting them 1/3 of the way back from the front and 1/3 the way forward of the back.
Make them trapezoid in shape with the angles the same as the amount of flare you want in the boat and the shortest parallel side the same width as the bottom of the boat at those two points. Our jigs are 3/4" plywood with 1/1/2 X 1 1/2 strips along the angled edges to give you something to clamp to. We use ours a lot so they're a bit more heavy duty then you'll actually need, but build what you want.

With your front stem piece installed, drop in the front jig and clamp the sides to it, drop in the back jig and clamp the sides to it. Flip the boat over so it's upright and you'll have an absolute working model of what it'll look like and you can play around with the transom dimensions until you get rocker you want. If you can't get the rocker you want and stil stay within your desired transom parameters, then you can trim the bottom edge of the sides to give you the desired rocker

This may seem a bit daunting but it's really not that bad and it gives you the option of seeing the final shape of your boat before you've glued and nailed yourself beyond the "point of no return"

Here's a shot of a typical jig

and here in place

 

[captaindoug]

Thank you for the suggestions and the great pictures showing how you do it. Looking at the photos of those beautiful planks of solid cypress being torqued into those curves makes bossin" around a little sheet of luan seem not so hard. I will definitely give your method a try, and I'm sure it will be worth the time to make the jigs you described. Getting off the tug Wed. morning, so I might get some boat shaped pieces of plywood put together by Wed. evening. I'll post shots of my progress, and thanks again for sharing the knowledge. Pretty clever by the way, how you are getting the 90 degree "clamping" effect, using the long boards and the counter weight, back aft in the picture.
I build model RC airplanes from scratch using pieces left over from my "learning experiences" (crashes) and an old mentor once told me I must be building them by the TLAR method. I asked him what that was, and he said, "That Looks About Right". They usually fly pretty good, so I guess I'll just have to use TLAR for this too.

 

[islandpiper]

I've found that I can crash a pirogue at full speed into nearly anything and it dings the paint. When I was flying RC i used to have bits of propeller stuck in the tail-wheel.

piper

 

[captaindoug]

Got started on my second pirogue, The "Bayou Skiff Lite". No offence, Uncle John. Like I said, I'm going by TLAR here. I made a little sled for my table saw to make some scarfs to stretch the ribs that needed some extra length. Two of them needed that treatment.

I guess I will have to scarf .the bottom joints of the ply because it doesn't seem as though the ribs will line up to do the same butt joints as on # 1. Ohba Wellba
I hope to get the gunnels and maybe the bottom on tomorrow, the epoxy will be kicked on the stretched ribs, so they should be up to the task, probably need to add a temp. thwart to the ribs again to take the stress of torquing the rails on.
This one has a 30" max beam at the bottom.

 

[oldsparkey]

Looking good , as they say , uncharted waters are Very interesting. Please keep us posted on your progress.

Chuck.

 

[Kayak Jack]

Doug, your TLAR system sounds similar to my BG&BG system - By Guess and By God. Sometimes, modifiers get added as suffixes.

 

[seedtick]

looks like you're making good progress

as Mick would say "good on ya"

Probably too late to help you now but there's a quick tutorial on custom making ribs in the rowing skiff thread, lets you put a rib anywhere you want

viewtopic.php?f=3&t=6295&start=45

quicker than double scarfing rib, gluing and waiting to dry IMHO

 

[captaindoug]

thanks for the great tip about the ribs, but as you surmised, I already did it the hard way.

Had to buy another sheet of 1/4 ply but I have another project in the wings so no big deal. I will be putting the rails and the bottom on this afternoon. Post pix later.

 

[captaindoug]

Got the rails and bottom on. I kinda like the shape. The final dimensions ended up being 13'-6 LOA, 28" max beam at the bottom, and 35 1/2" beam at the rail. Had I started from scratch, I would have tried to make it a little bigger, because my big plan to have them nest is not going to work out all that great, they will still fit together but not as I envisioned.

I ended up with a disproportionately "equal" rib spacing, so I will definitely need to add some bottom stringers at least in the aft portion.

I cut down the rubrails on my cheapy little table saw and the fence moved on me, and they ended up being a bit thinner than I wanted. I will need to add an inwale to beef up the top edge. Oh well, minor details, details, details.

The bottom ended up with a fair amount of rocker in it, which I was hoping for. Glassin' it up tomorrow, and might try a test float Monday or Tuesday.

 

[captaindoug]

Well, Chuck shamed me into taking a little more time and putting a bit more care into this, after reading his posts on his skiff build. I decided to add a bit of reinforcement to the transom so when I get some power (a trolling motor) I fish a lot of combustion exclusion zones. I also added gussets to the ribs.

I guess I'll fill a caulking tube with fillet goo so I can tape the seams inside next.

 

[oldsparkey]

:lol: :lol: :lol:

You did the same thing that I plan on doing to the transom where it meets the bottom of the boat. The Dog Leg in there will sure help everything distribute the load from the motor pushing the boat along. Especially if you hit something with the lower foot and then it slams back down on the transom.

I plan on having two since the boat will be trailered with the motor on it and any reinforcement is needed to be on the safe side , along with the corner braces you installed on yours. Last thing I want is for the transom to fall off , either on the road or on the water with it. Neither would be a good thing. :wink:

As Kayak Jack likes to tell folks , the worse sound you can hear on the water in a wood boat is a loud ..... KRACKkkkkkkkkkkkk. I have to agree with him on that , it would be no fun if it came from your boat.

Chuck.

 

[captaindoug]

We are getting ready to epoxy / graphite the bottoms of the "yachts" this week and my question is this, does the graphite protect the epoxy from UV deterioration, or do you still need to put a UV inhibitor / varnish over the bottom once all the graphite mix is on :?:

 

[oldsparkey]

Not sure about the rest but all I worry about the UV angle is to varnish the sides and inside to protect the epoxy. The graphite is on the bottom and the only thing that see's it are the fishes when it is in the water and the State Troopers in the sky ( doing speed checks) as I drive between paddling areas.

Never thought about the bottom plus any varnish on there would not stick due to the graphite. My boats are stored under cover and out of direct sunlight when not being used. Off hand I would say , it is not needed , but if a person would want to.........

Technically I think the graphite would protect the epoxy and the glass the graphite is going over ..... As far as the portion that is exposed , it should protect the greater majority of it since it has to be exposed for a lengthy period of time to discolor.

Chuck.

 

[Kayak Jack]

Disregard applying UV protection to the bottom. It is seldom exposed to UV rays, and varnish is softer than epoxy. Save your money for (fill in appropriate adult beverage here).

 

[captaindoug]

nothing less than 12 years old.

 

[captaindoug]

That's Right!

 

[Kayak Jack]

nothing less than 12 years old.

... and single malt.

 

[captaindoug]

Found a neat little roller and tray at Home Depot, was able to coat the entire boat, inside and out with two coats of epoxy and the little roller made it through the whole job with very little fuzz or lint coming off, and almost no runs, nice even coats. The best part, $1.97 per each.

 

[captaindoug]

As Chuck has been dealing with "too cold to kick epoxy", so have I, but today in Tampa Bay we saw 60 degrees,(for 12 minutes) the Bayou skiff Lite needed the coat of glass on the hull. I was concerned that I worked so hard to make it boat shape, and then if I didn't get it sealed up, the whole thing needs a whole start over. Will add pix in the morning.