Coming along nicely. You showed how you pre-bent the inside chine and attached to each side, but looking at the photo just prior to putting the bottom on, those inside chine pieces look perfectly flat, or I guess I should say, aligned with the plane of the bottom. Did you cut the inside chine with that angle before you nailed it to the sides, or is that attained by planing and sanding? If you cut it first....., well that's some pretty good geometry you got going on there.
A New Marsh Pirogue
- Thread starter islandpiper
- Start date
sorry Capt'n
reckon I just skipped over that step, the inside chine is cut to match the angle of the side flare at the middle of the boat, so it should be flat at the middle and
yes we plane down the sides and the chine to flatness crossways and to match a fair curve fore and aft
dosn't have to be perfect, we shoot for a bottom/side gap no thicker than a credit card, but filled expoxy bridges and holds very well on larger gaps than that
reckon I just skipped over that step, the inside chine is cut to match the angle of the side flare at the middle of the boat, so it should be flat at the middle and
yes we plane down the sides and the chine to flatness crossways and to match a fair curve fore and aft
dosn't have to be perfect, we shoot for a bottom/side gap no thicker than a credit card, but filled expoxy bridges and holds very well on larger gaps than that
with the bottom on, the next step is to attach the batter boards
then the outside top rails and those little spacer thingys if you want someplace to tie down stuff
then attach the inside top rails
then the outside top rails and those little spacer thingys if you want someplace to tie down stuff
then attach the inside top rails
You mentioned waiting for the temp to come up so you could get the epoxy to set, is that some sort of thickened stuff or straight or just waterproof wood glue? Also, the fastenings? Galv., Bronze, stainless? Nail.. or screws?
Everything is glued AND mechanically fastened
The glue is West Systems marine epoxy, thickened with sawdust (from RO sanders) and a little bit of colloidal silica. We follow manufacturer's guidelines and don't use epoxy below 60 F. The epoxide reaction requires a certain amount of fluidity for the cross linking polymer chains to grow properly and achieve maximum strength. When the temperature is too low, the epoxy will set but will not have the strength
That's the best we know of but we also know that maybe hundreds of thousands of boats in the last 60 or so years were built with Weldwood powder (http://www.amazon.com/Pack-00204-Weldwo ... B002YV0Q20). I've still got my Dad's old bateau from the early 50's that is still being held together with Weldwood.
Fasteners are a variety, depending on the application
Nails are ring shank silicon bronze or 316 SS - this is what we use most of the time
The shortess ring shank nails we have are 3/4", so where we need a fastener shorter than 3/4", we use galvanized staples
SS screws are used for planks or plywood in an end grain application, e.g. edges of ribs and transoms
The glue is West Systems marine epoxy, thickened with sawdust (from RO sanders) and a little bit of colloidal silica. We follow manufacturer's guidelines and don't use epoxy below 60 F. The epoxide reaction requires a certain amount of fluidity for the cross linking polymer chains to grow properly and achieve maximum strength. When the temperature is too low, the epoxy will set but will not have the strength
That's the best we know of but we also know that maybe hundreds of thousands of boats in the last 60 or so years were built with Weldwood powder (http://www.amazon.com/Pack-00204-Weldwo ... B002YV0Q20). I've still got my Dad's old bateau from the early 50's that is still being held together with Weldwood.
Fasteners are a variety, depending on the application
Nails are ring shank silicon bronze or 316 SS - this is what we use most of the time
The shortess ring shank nails we have are 3/4", so where we need a fastener shorter than 3/4", we use galvanized staples
SS screws are used for planks or plywood in an end grain application, e.g. edges of ribs and transoms
Seedtick, I've used light bulbs to add heat for epoxy, but your shed seems pretty open to try heating for that. I wasn't aware of the polymer chain links in there being temperature sensitive; good info. That'll hold his boat together nicely.
seedtick said:
Is that a strap hooked to the C clamp, pulling the rub rail tight against the hull? I think I understand what I am seeing, but not sure. I haven't seen that trick before.
George
got a propane heater in the 30 X 30 closed section of the shop, works good to get the temperature up, then have electric heaters on thermostat to maintain temperature
that's a bungee cord on the C-clamps holding the rail tight
that's a bungee cord on the C-clamps holding the rail tight
construction complete, a saturation coat of epoxy on the outside
at the same time we were building a plank version of the marsh pirogue, here it is, ready to be varnished
at the same time we were building a plank version of the marsh pirogue, here it is, ready to be varnished
When you get them completed, I'd be interested in a weight comparison between the plank & plywood versions? Piper San will enjoy that boat. Maybe he can design a cooler or a fish tank too.
plywood: length = 15 feet - 51/2 inches
weight = 70 lbs.
beam / top = 40 - 1/2 inches
btm = 26 - 1/2 inches
side angle = 36 degree
cypress: length = 15 feet
weight = 100 lbs.
beam / top = 41 inches
btm = 29 inches
side angle = 30 degree
weight = 70 lbs.
beam / top = 40 - 1/2 inches
btm = 26 - 1/2 inches
side angle = 36 degree
cypress: length = 15 feet
weight = 100 lbs.
beam / top = 41 inches
btm = 29 inches
side angle = 30 degree
Yeah, these aren't the kind of boats you throw up on your shoulder and march off with, eh? They look sturdy as heck, though.
70lbs wouldn't be all that bad with one of those canoe carts, but loading it car-top would be a bit much. If you could just slide it off the back of a pick-up and have a cart to get it to the water, even 100 wouldn't be completely out of the question.
Seedtick - does the plywood boat get glass inside or out?
George
ps - still love the shape of the cypress marsh pirogue. I think that is one of the prettiest boats I've seen.
70lbs wouldn't be all that bad with one of those canoe carts, but loading it car-top would be a bit much. If you could just slide it off the back of a pick-up and have a cart to get it to the water, even 100 wouldn't be completely out of the question.
Seedtick - does the plywood boat get glass inside or out?
George
ps - still love the shape of the cypress marsh pirogue. I think that is one of the prettiest boats I've seen.
weight was not a major concern for us. Whether or not 70 lb is too heavy depends on the lifter and his technique. My Dad was able to put a 100 lb bateau on the roof rack of a car well into geezerdom. The trick is to not try to lift the boat completely in the air
plywood is marine fir plywood
1/4" sides and 3/8" bottom, it does not need glass to be structurally sound
we epoxy saturate because the veneer layer tends to check over time
plywood is marine fir plywood
1/4" sides and 3/8" bottom, it does not need glass to be structurally sound
we epoxy saturate because the veneer layer tends to check over time
As far as loading the boat on a truck rack is concerned. We can find out in March. I will have an emty rack and if someone will divert Pipers attention for a couple of min. once I get clear, I'll let y'all know if it was easy or not. :wink:
Baldy, if you keep those clown shoes to home, and stay out of my way at the bacon, I'll create the diversion you are asking for. Otherwise, I'll watch you like a hawk.
Keith and Seedtick, thanks for the great post. You truly spread the wealth of knowledge you have. You say the plank boat and the ply version were built side by side. They are very similar in size, with the exception of the bottom width and flare.
Plywood
btm = 26 - 1/2 inches
side angle = 36 degree
Cypress
btm = 29 inches
side angle = 30 degree
You fellas use those jigs to determine the flair and width of your builds, question I have, is the difference in the two boats just different placement of the jigs, or is it different jigs? Are you you gonna paint Piper's boat? Also, I was surprised by the fact you installed no side ribs in the ply wood boat. Doesn't need them apparently, but I would have figured the pirogue needed ribs, and would have over built. Obviously you guys have been there, done that, to know it isn't needed. Oh, and please don't be shy in posting a few photos of that beautiful cypress planked Marsh Pirogue.
Plywood
btm = 26 - 1/2 inches
side angle = 36 degree
Cypress
btm = 29 inches
side angle = 30 degree
You fellas use those jigs to determine the flair and width of your builds, question I have, is the difference in the two boats just different placement of the jigs, or is it different jigs? Are you you gonna paint Piper's boat? Also, I was surprised by the fact you installed no side ribs in the ply wood boat. Doesn't need them apparently, but I would have figured the pirogue needed ribs, and would have over built. Obviously you guys have been there, done that, to know it isn't needed. Oh, and please don't be shy in posting a few photos of that beautiful cypress planked Marsh Pirogue.
we used two different sets of jigs. You just can't bend around and twist a 5/8 or 3/4" solid plank like you can a 1/4" piece of plywood
we typically paint plywood boats and varnish the plank boats
marsh pirogues are a style that was traditionally built without ribs. Not to hurt anybody's feelings, but we're using real marine plywood and not luan. Big difference in the quality of the panels. IF i had to build one out of luan, it would have ribs.
Adding on ribs would no doubt make it stronger - 9 ribs would be stronger than 7, 7 stronger than 5, etc. But the folks that started building these when marine plywood became readily available after WWII deemed the ribs unnecessary. Our experience confirmed this
we typically paint plywood boats and varnish the plank boats
marsh pirogues are a style that was traditionally built without ribs. Not to hurt anybody's feelings, but we're using real marine plywood and not luan. Big difference in the quality of the panels. IF i had to build one out of luan, it would have ribs.
Adding on ribs would no doubt make it stronger - 9 ribs would be stronger than 7, 7 stronger than 5, etc. But the folks that started building these when marine plywood became readily available after WWII deemed the ribs unnecessary. Our experience confirmed this