Nice progress! Not sure the maths checks out on adding to the frames though. Since the paulownia is lighter than water, the more you add the higher the boat floats. Below the waterline anyway. And since it’s so light, the added thickness under water can easily support the added thickness in the topsides.
Appreciate your astute comment and I probably should have explained better that the cause of wanting to increase the displacement at that late stage was because my spreadsheet sum of weights, was starting to compromise some of my decisions as to what weight I added. If it was purely a race yacht, and there wasn't a tight budget, I might have better kept to my original target. I used to build steel yacht hulls to someone else's designs and people were forever having to raise their waterline paint, I'm trying to head that situation off while keeping in mind, any % of weight saving on anything you can, adds up.
New to the concept of boat building…. Enjoying the channel and videos very much, very helpful. What happens to this upside down hull at the end, do you remove those frames or do they become the bulkheads?
Good to hear you're enjoying the channel! I'll be leaving the temporary frames in as long as possible and remove them after the deck is on so the hull stays in shape. To help with that, I have made some temporary gunnels. I'm working on the deck at the moment after I recently turned over the hull.
Nah, you don't need more frames, just use some home made "clothespegs ", V shaped forks of wood, and use them to line up the top plank with the other lower ones. I built a 16ft Canadian canoe with a lot thinner strips and the same mould spacing.
Thanks for the comment and you're probably right, however, although I like trying new ideas and in the case construction methods (new to me) if I have a doubt about something I try to 'encourage' myself to take the conservative choice and it was more about spacing the skins further apart to give a stiffer panel as I'm planning on using a minimum of internal structure. Another lesson for me was to not follow the gunnel for the first plank but lay it around the hull where it more naturally wanted to lay. By doing it the way I did, one edge always wanted to kick out and the other kick in. So they weren't staying as fair as I'd like between the frames (they were being stressed in their most resistant direction) and I really did want to minimize the fairing I needed to do, to save weight, work and materials. Sounds like your canoe turned out well!
Something I also have to admit and deal with is I've been told more than once by friends I need to not strive for perfection (to me it's far from it!), and it's true, perfection is the enemy of getting a boat in the water!
Looks great Karl! just wondering, do you resin soak the timber before applying the thickened epoxy to glue the join, or have you found a way to still make the join strong while missing this step? Cheers
Cheers Ezra. Good question. In this type of construction the strength of the boat does not rely on the joint being strong, so much so that butt joints can even be used as long as they are not side by side. The reason is the timber over all acts like a finger joint, the real strength as with foam construction, is from the skins. Paul from the club told me he built a catamaran and experimented with using fairing resin and micro balloons to join the planks to avoid the problem I had in that the glue line is a lot harder than in his case Cedar, more so for Paulownia. He found the planks did not break on the glue line and from what I've seen, I'd agree. But yes, it's still good to use a scarf joint because it helps keep the 'planks' fair. It does glue very well I've found, without having to pre-soak the timber and doesn't seem to over absorb the resin in the glue and dry the joint. It's very nice to work with! a little over 200kg a cubic meter whereas Cedar is about 385. However, as I've mentioned in video, I did go thicker than required for cedar as you might with foam, but mainly because skins of the same weight further apart make a stronger result and it also aids in construction and therefore I can use less internal structure.
Great work!, I could easily watch another hour of you building the hull. One thing that would also be of interest is where you sourced the Paulownia from, and what the approx cost for a boats worth is?
Thanks for the comments! This paulownianz.co.nz/ is the source of the timber, really good people to deal with, great to see it growing on the farm, using cow dung nutrients. I'm not too sure of the cost relative to cedar, in my part of the world, and probably would have used poplar from just down the road if I hadn't used Paulownia but the cost of the timber for this yacht was a bit over $6k NZ. I could have used less but I intend to use it instead of plywood, so am using quite a bit.
@@KarlFullerNZ > Thanks for the info, I will be following along with interest. One more thing, I went to look at your earlier videos, yet only the current one and one other turned up, I thought I had watched more than that already, is RUclips deleting them from your playlist?, it would be nice to go back and review your design talks again.
@@BlueChromegood that you're keeping an eye on RUclips for me! I've had a look and if you go to my channel and hit the videos option you should see the 4 videos I've made on this design and build.
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Nice progress! Not sure the maths checks out on adding to the frames though. Since the paulownia is lighter than water, the more you add the higher the boat floats. Below the waterline anyway. And since it’s so light, the added thickness under water can easily support the added thickness in the topsides.
Appreciate your astute comment and I probably should have explained better that the cause of wanting to increase the displacement at that late stage was because my spreadsheet sum of weights, was starting to compromise some of my decisions as to what weight I added. If it was purely a race yacht, and there wasn't a tight budget, I might have better kept to my original target. I used to build steel yacht hulls to someone else's designs and people were forever having to raise their waterline paint, I'm trying to head that situation off while keeping in mind, any % of weight saving on anything you can, adds up.
New to the concept of boat building…. Enjoying the channel and videos very much, very helpful. What happens to this upside down hull at the end, do you remove those frames or do they become the bulkheads?
Good to hear you're enjoying the channel!
I'll be leaving the temporary frames in as long as possible and remove them after the deck is on so the hull stays in shape. To help with that, I have made some temporary gunnels. I'm working on the deck at the moment after I recently turned over the hull.
Nah, you don't need more frames, just use some home made "clothespegs ", V shaped forks of wood, and use them to line up the top plank with the other lower ones. I built a 16ft Canadian canoe with a lot thinner strips and the same mould spacing.
Thanks for the comment and you're probably right, however, although I like trying new ideas and in the case construction methods (new to me) if I have a doubt about something I try to 'encourage' myself to take the conservative choice and it was more about spacing the skins further apart to give a stiffer panel as I'm planning on using a minimum of internal structure.
Another lesson for me was to not follow the gunnel for the first plank but lay it around the hull where it more naturally wanted to lay. By doing it the way I did, one edge always wanted to kick out and the other kick in. So they weren't staying as fair as I'd like between the frames (they were being stressed in their most resistant direction) and I really did want to minimize the fairing I needed to do, to save weight, work and materials.
Sounds like your canoe turned out well!
Something I also have to admit and deal with is I've been told more than once by friends I need to not strive for perfection (to me it's far from it!), and it's true, perfection is the enemy of getting a boat in the water!
Looks great Karl! just wondering, do you resin soak the timber before applying the thickened epoxy to glue the join, or have you found a way to still make the join strong while missing this step? Cheers
Cheers Ezra. Good question. In this type of construction the strength of the boat does not rely on the joint being strong, so much so that butt joints can even be used as long as they are not side by side. The reason is the timber over all acts like a finger joint, the real strength as with foam construction, is from the skins. Paul from the club told me he built a catamaran and experimented with using fairing resin and micro balloons to join the planks to avoid the problem I had in that the glue line is a lot harder than in his case Cedar, more so for Paulownia. He found the planks did not break on the glue line and from what I've seen, I'd agree. But yes, it's still good to use a scarf joint because it helps keep the 'planks' fair. It does glue very well I've found, without having to pre-soak the timber and doesn't seem to over absorb the resin in the glue and dry the joint. It's very nice to work with! a little over 200kg a cubic meter whereas Cedar is about 385. However, as I've mentioned in video, I did go thicker than required for cedar as you might with foam, but mainly because skins of the same weight further apart make a stronger result and it also aids in construction and therefore I can use less internal structure.
Great work!, I could easily watch another hour of you building the hull.
One thing that would also be of interest is where you sourced the Paulownia from, and what the approx cost for a boats worth is?
Thanks for the comments!
This paulownianz.co.nz/ is the source of the timber, really good people to deal with, great to see it growing on the farm, using cow dung nutrients.
I'm not too sure of the cost relative to cedar, in my part of the world, and probably would have used poplar from just down the road if I hadn't used Paulownia but the cost of the timber for this yacht was a bit over $6k NZ. I could have used less but I intend to use it instead of plywood, so am using quite a bit.
@@KarlFullerNZ > Thanks for the info, I will be following along with interest.
One more thing, I went to look at your earlier videos, yet only the current one and one other turned up, I thought I had watched more than that already, is RUclips deleting them from your playlist?, it would be nice to go back and review your design talks again.
@@BlueChromegood that you're keeping an eye on RUclips for me! I've had a look and if you go to my channel and hit the videos option you should see the 4 videos I've made on this design and build.