Canoe Lofting made easy

hi everybody chuck here with jenkins boatworks welcome back uh focus has shifted we are starting to work on a freedom 17 this is a 17 foot canoe out of ted moore's book canoe craft canoe craft is widely revered as pretty much the bible of cedar strip canoe and kayak building and we are taking a plan out of the book there's five or six plans within the pages of the book so if you're looking for a canoe to build they're in there the only trick is you got to be able to figure out how to get the the offsets and the the half breadths out of the pages and onto a graph and so that's what we're going to do today we're going to do the plotting and lofting of the plans for the freedom 17. and after editing the video i feel like i jump all over the place uh in various parts of it and the whole thing seems like it shouldn't be as confusing as it is and i'm so i'm just going to apologize now for the fact that i feel like a jump all over the place but if if you watch and listen and you're trying to figure out how to do lofting i think that it'll all come together and make sense it's really not super difficult you have to have some understanding of the terminology which we'll go through and so anyway just just watch and then if you need to go back and look at particular sections do that and if you have questions or comments of course put those down in the comments we'll be happy to discuss that and there's a lot of canoe building goes on in the winter time and i know many projects have already started so i'm a little late to the party on mine because i've been busy working on the haven and quite honestly there are some other things that we're going to still be doing on the haven uh that may intersperse uh video episodes between this and that but that happened before when we were building the stitch and glue kayak so anyway i think i can do two things at once well anyway we're glad you're here if you haven't already subscribed to the channel please do uh if you want to click the little bell to get notifications of future um videos do that we're going to do a whole series on this canoe and i'm really excited about it done one before and and i learned a lot the first time and i think we'll have a lot of good information to share there are varying opinions on how you how you do these and how you put them together and there's not any super one way right answer but uh anyway we'll do the canoe lofting in this in this episode and hopefully uh you can get something out of that like i said if you have questions put them down in the comments all right let's jump in all right we've got some of these stations for the freedom 17 plotted out and in this particular canoe it's asymmetrical so in other words uh you'll be able to tell what is the bow and what is the stern [Music] a couple of important things to note we're going to show how we get all these various stations how we loft them out of the book here in just a second but i've got stations 16 which is the aftermost i believe 15 14 13 12 and so on and i happen to do number four clear down there because i had the paper that was the right size for it you're going to hear the words butt line this is your very bottom most part that mounts on the strong back there is the strong back which is no longer living in my hay loft it's the one we used when we did that canoe so it's going to have to be modified a little bit those cross pieces you see on the top there they're just pieces of 2x4 screwed into the top of the strongback each one of those had a station set up on it and so you'll notice say here on 14 it looks like a mushroom and so this part down here which is about eight inches wide that'll actually be cut out of plywood and that's what will mount the stations onto those two by fours that are crossways on the strongback part of the reason i laid these out is because i want you to see something this boat's going to have a bit of rocker to it which means that on the ends it will come up and even the shear line has a bit of a sweep to it so these are all set up pretty much on the edge of this workbench and if you look and see where the shear lines are like here you'll notice that those shear lines are going up as we get down the workbench now they even out up there in the middle of the boat a midship because in the middle of the boat it's pretty pretty fair pretty straight the other thing you'll notice is these profiles here this is your highest point on the form and so on those say here's station 12 we're at about 20 inches so that'll be 20 inches high off of the strong back same thing here at station 11 20 inches that res represents what will be like the keel the most bottom part of the boat so if you can look back at those you'll notice that those get shorter as we get all the way down here so in the very last station close to where the after stem will be see that one's only a little better than 18 about 18 and a half inches that's what creates your rocker you think of it like a rocking chair all right so just as a point of definition the profile is your height all the way from the butt line which is this very bottom part here your water line denoted by wl in some cases i write it out it's not always the same what how i do it and then i've just got it marked off in inches so 2 4 6 8 10 12 all the way up to in this case 19 and 5 16. you're basically just plotting out a graph that we will then transfer onto plywood and cut these out okay so you've got a butt line i wrote it on this one a shear line which is basically where your gunnels are and then the profile those are all very important terms that we need when we go to look at the offsets and the half breadths so let's go do that so this bench over here is where i will make my strips and scarf them together over here is just this was my sewing table is now turned into a lofting table and canoe craft by ted moore is considered to be sort of the bible of cedar strip canoe design and building i'm using this this graph paper and the graph paper i like this because it's set up in one inch squares and they're divided into four so that tells me quarter inch within each of those squares i got this paper at just a office supply store if i could get it at a art supply something like that i got this a long time ago when i did the first canoe bien fang 4x4 gridded paper i really like it because i can use those squares to mark out my distances without having to completely rely on my metal yardstick which is hiding under there let's start out with a couple of definitions we need to know what our base or butt line is our shear line and the profile what we're doing is we're taking these numbers off of these table of heights and the half brett's and we're transferring them onto a graph paper so that we can make the various stations in this case 16 to build this freedom 17. the shear line is along the gunnel now when you make these stations you make them upside down because you build the boat upside down so this down here represents each of the stations all these lines so if we see that one there well let's go on over to number eight let's see right here see it's pretty much a mid ship part of the widest part of the boat so i've started doing it on here and i've got my grass graph paper and you need to know what your sheer line is because that's the even though you're building it upside down that's your top edge of the of the mold and kinda it's the top of the boat the profile although it's the top top of the the graph paper here is actually the keel that's the bottom of the boat and on this particular form the profile is 20 inches so on the water lines which is the vertical you count all the way from the butt line which is clear down here see i wrote it on there butt line and you count on the butt line and you measure up 20 inches and any kind of water line measurement that you have is based off of this bottom base line not off of the shear line it tells us in here that the shear is at seven inches right here those numbers are in feet the second number is inches the third number is eighths of inches and then if there's a plus sign that means add a 16. so here where it says shear over here you come across we're on station number eight zero feet seven inches zero eights so so we know it's seven inches up it's the table of heights so it's seven inches up well that's an easy one you just mark that off at seven inches you draw a line across fifteen and seven eighths why does it say fifteen seven eighths at the end of the shear line let's find out in the half breaths so that's the widths the widths halfway on each side of the center line for number eight says one foot three inches seven eight one foot three inches twelve threes fifteen inches and seven seven eighths so what we did on that one from the center line the half breadth we come across all the way until we get to 15. i've got a mark on the butt line every two inches well until i get out to there where i mark the fifteen every two inches is our widths or half breadths and you gotta do it on each side and there it is so we know that on this particular mold it's going to be 31 plus inches 15 and 15 and 7 8 and 7 8 that's how wide the canoe is at the top at the gunnel so now we're going to use the water line measurements and the butt line measurements and figure out what the rest of this mold looks like more in a minute one more thing how did we know that the profile was 20 inches well in the table of heights we come down to profile come across to number eight and it is one foot eight inches well one foot eight inches that's 20 inches so from the very bottom down here we go all the way up here 20 inches we know that that is the deepest part or the highest part of this particular mole okay more in a minute okay so i've plotted in the the table of heights so this top section up here for number eight and so the shear line we knew was at seven inches right that's how high it is up off of the butt line the next one but two inches is one foot seven inches or 19 inches and seven eighths so on the two inch butt line we go up 19 and 7 8. and you can see it that's just right close to the 20. it's only two inches away from the center line so you got a slight curve coming down on the six inch butt line go straight up there and we're 19 and a half the book says it's 1-07-4 that's four-eighths it's a half-inch one foot seven inches 19 and a half let's double check that six inch butt line six inch station eight wait a minute where are we that's a six inch i think i goofed it up i was on the number nine one it's not right i have to change that one it should be 19 inches 3 8 plus how about that so i caught my mistake on this six inch butt line i was on station nine and we're on station eight so i have now corrected that and it was 1-07 three plus so one foot seven inches or 19 inches 3 8 plus a 16. so now we're just above the 19 mark well it's not marked but that's the 19 inch line 19 inches each little tiny square is a quarter inch so 2 8 3 8 plus a 16. okay so you just do that until you get all of them now what's interesting is like there's the the 14 inch butt line clear up here and you can see how far it's still up there on a nice flat curve coming out from the middle of the canoe but then two more inches over and suddenly we're clear down here so that's a 16 inch butt line right and that's at the widest point but that one's only seven inches off of the off of the the height so see it's right close to the shear line because the shear line's at seven inches very interesting all right now we'll do the half breaths i'm gonna plot a few of those and then we'll come back okay so now we've plotted the water lines and the beauty of this is that they start to intersect with the butt line measurements so the table of heights start intersecting with the half breads and it's kind of a check system to where you can see if your curve is going to be right and if they're mating up so the first one on number eight is water line eight inches water line eight inches table station eight one dash o four so that's one foot four inches no eights sixteen inches that's an easy one so water line eight here water line remember counts up that's eight inches from the base and so we go over sixteen inches one dash oh four zero sixteen inches and you come clear over here until you're on 16 inches away so that's that mark right there now the last butt line that we did was also 16 inches right there well here the 16 inch butt line was there so we know there's the shear line where the gunnel is it's going to come up to here up to here and then the next one's two inches up now that one is one four one plus or one foot four inches 16 inches and an eighth plus a sixteenth plus designates add a sixteenth let's double check that one that is water line number ten water line number ten station eight one four two there we are 142. that is water line 12 is that where we were at water line 12. 142. i think we were on 141 plus which is this one so we're basically doing two here so there's that one and then there's that one and you just keep plotting them up there so this one here at number 16 water line 16 it's 15 and three eighths it's designated as one three and three so it's one foot three inches and three eighths so 15 inches and three eighths so see now we're in between that 15 and the 16 from down here you're just measuring out from that center line you do that then the next one plots up here now these two one was a butt line and one was a water line but then if we pull back here you can see what the shape of this whole thing looks like from the profile up there it's a flat fairly flat bottom slight curve until we get over towards the side of the canoe and then it really curves until we get all the way down here to the shear line now of course you have to plot these on the other half of the paper and so you can see i've got all my little marks there and you basically just connect the dots until you have the whole pattern that you lay out on your plywood and you cut out we'll quickly take a look at the last one we did before this which i kept trying to do again because i kept shifting the wrong thing here is station number nine and you can see these dots are all connected and so that's what that's going to look like now this part down here where we just got straight lines coming down i do them on the six inch mark that's 12 inches and that's the that's the part that's you're not building a canoe off of that that's just the part that connects to the strong back where you set it up so that that's that mushroom is sticking up in the air and we'll have 16 of those dudes the whole length of that strong back so that then we can build our canoe off of these and you can see we've got multiple molds already made which we looked at those in an earlier video anyway the book canoecraft says this is too complicated for their discussion and as i'm trying to video it and describe it i see why they didn't try to tell you how to do it in the book but once you get started on it as long as you stay in the right column and don't plot the wrong deals it gets to where it's pretty easy you look at 1-6 and you know it's 18 inches you know stuff like that all right good luck thanks for watching we'll see you next time

Channel: Jenkins Boat Works

Views: 8,385

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Id: tJHUN8Xm9LE

Length: 23min 21sec (1401 seconds)

Published: Thu Dec 03 2020