Hi Bryan,
Do you wet out both layers at the same time? I do remember John Winters wrote somewhere that he has used 4oz cloth, laying it perpendicular to the length of the boat, and overlapping it by a few inches as he worked his way down the hull, calling it sort of a 'frame stiffener'.
And Bernie, thanks for the additional info on the chart numbers. I guess you have to take these sorts of things with a grain of salt. Always best to do your own testing anyway, as that would more closely match exactly what you are trying to do.
Moonman.
Light weight Canoe
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BearLeeAlive
- Posts: 196
- Joined: Tue Aug 18, 2009 7:00 pm
This is all great info. I am very close to building my first canoe, which is a solo, It is the Kite, which is basically a modified Osprey with a full sweep to the shoulder. This is a photo of the only one built to date by Martin Step at Green Valley. I had bought the plans before he had announced it to the public.
I have all my strips cut to 1/4 x 3/4, and plan to plane them down to 3/16", and it sounds by the conversation on this thread that wound be an ok thing to do. I would be doing a bead and cove with a 1/4"R bit.
Woodwork is no problem for me, this glassing bit does have me a little confuzzled though. If I was to use something like the 3.2 oz tight weave, would it be advisable to double it only on the football, or the entire surface? On the inside of the hull, would it also be advisable to double up in the bottom to help support my 220 lb frame? This canoe would be for flat water only.
And on the topic of light weight, and considering that the hull in the Kite should be quite strong near the shear due to the sharp shoulder (hope I am using the right term here), I am thinking I could cut down on the size of the gunwales somewhat. I plan to mount a sliding seat on a platform so it would not be hung from the gunwales. The thwarts could be attached without too wide of a gunwale too. I was thinking 3/8"x3/4" on the outwate, and 5/8"x 3/4" for the inwale. I am thinking of using cherry as I want a fairly tough wood, I like the look of it too. Would this be going too small?
I have all my strips cut to 1/4 x 3/4, and plan to plane them down to 3/16", and it sounds by the conversation on this thread that wound be an ok thing to do. I would be doing a bead and cove with a 1/4"R bit.
Woodwork is no problem for me, this glassing bit does have me a little confuzzled though. If I was to use something like the 3.2 oz tight weave, would it be advisable to double it only on the football, or the entire surface? On the inside of the hull, would it also be advisable to double up in the bottom to help support my 220 lb frame? This canoe would be for flat water only.
And on the topic of light weight, and considering that the hull in the Kite should be quite strong near the shear due to the sharp shoulder (hope I am using the right term here), I am thinking I could cut down on the size of the gunwales somewhat. I plan to mount a sliding seat on a platform so it would not be hung from the gunwales. The thwarts could be attached without too wide of a gunwale too. I was thinking 3/8"x3/4" on the outwate, and 5/8"x 3/4" for the inwale. I am thinking of using cherry as I want a fairly tough wood, I like the look of it too. Would this be going too small?
Last edited by BearLeeAlive on Fri Oct 29, 2010 7:29 am, edited 1 time in total.
-JIM-
Hi Jim,
I guess using the 3.2oz cloth to save weight depends on how light you are trying to get to. That cloth may be hard to get as well, especially if you live in Canada (wish we had a better choice of fiberglass up here). I can't give knowledgeable advice on the best layup for that cloth (having not used anything but 6oz) but for the gunwales, I think you'll be okay. On my Winisk, I used 1/2" x 3/4 outwales and 1/2" x 3/4" inwales, with 1/4" x 3/4" x 3" long scupper blocks. I used cherry for the rails and walnut for the scuppers. I also epoxied everything to the hull. Its plenty strong and I don't baby that boat - its taken a beating on lots of trips.
Moonman
I guess using the 3.2oz cloth to save weight depends on how light you are trying to get to. That cloth may be hard to get as well, especially if you live in Canada (wish we had a better choice of fiberglass up here). I can't give knowledgeable advice on the best layup for that cloth (having not used anything but 6oz) but for the gunwales, I think you'll be okay. On my Winisk, I used 1/2" x 3/4 outwales and 1/2" x 3/4" inwales, with 1/4" x 3/4" x 3" long scupper blocks. I used cherry for the rails and walnut for the scuppers. I also epoxied everything to the hull. Its plenty strong and I don't baby that boat - its taken a beating on lots of trips.
Moonman
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Glen Smith
- Posts: 3719
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- Location: Baie-St-Paul, Quebec, Canada
This seems like a waste of wood. If it is smooth on all sides, I would run them through the tablesaw using a thin kerf Freud 7.25" blade. It has a 1/16" kerf so the strips should just need a quick pass through the planer to get them all to the same thickness.I have all my strips cut to 1/2 x 3/4, and plan to plane them down to 3/16"
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BearLeeAlive
- Posts: 196
- Joined: Tue Aug 18, 2009 7:00 pm
Moonman, I am not extremely worried about weight, I would just like it to be as light as possible without compromising the strength. I can handle my 40 lb Swift Winisk with no problem at all.
In doing the 5/8" inwales, I also planned on routing in 1/4 scuppers, somewhat for weight savings, but mostly for a place to attach stuff.
Glen, I have both fat fingers and poor editing skills. The strips are at 1/4x3/4 right now. I used either the Freud blade you mentioned in my cabinet saw, or a resaw blade on my bandsaw to do the ripping. I was given a 20' chunk of WRC by a friend to use, so ended up with lots of strips. About 60 clear, and another 80-100 with one scarf joint if I want or need. That, and a huge pile of kindling too. :)
In doing the 5/8" inwales, I also planned on routing in 1/4 scuppers, somewhat for weight savings, but mostly for a place to attach stuff.
Glen, I have both fat fingers and poor editing skills. The strips are at 1/4x3/4 right now. I used either the Freud blade you mentioned in my cabinet saw, or a resaw blade on my bandsaw to do the ripping. I was given a 20' chunk of WRC by a friend to use, so ended up with lots of strips. About 60 clear, and another 80-100 with one scarf joint if I want or need. That, and a huge pile of kindling too. :)
-JIM-
BearLeeAlive,
The outwales were 3/16 ash rabbetted out to an L shape so that the sheerline was capped on two sides. I've been using the Huron for several years now with no problems and I'm probably heavier than the average paddler.
PS... I went with 6 oz glass inside and out, and the outside bottom got an extra layer for any abrasion. The last several canoe trips have been kinda rough, dragging the canoe fully loaded over beaver dams and onto shore at campsites so while roughing it out there the extra durability may have done some good. I also thickened the keel line under the stems quite a bit for skid plates, although the wear there is less than I thought it would be.
I used 3/4 inch square pine on the inwales for my Huron and there is no shouldered tumblehome on it like there is on the Kite... so going with thin inwales would probably be OK with the extra stiffening near the sheerline (the shoudered tumblehome) that the Kite will have.And on the topic of light weight, and considering that the hull in the Kite should be quite strong near the shear due to the sharp shoulder (hope I am using the right term here), I am thinking I could cut down on the size of the gunwales somewhat. I plan to mount a sliding seat on a platform so it would not be hung from the gunwales. The thwarts could be attached without too wide of a gunwale too. I was thinking 3/8"x3/4" on the outwate, and 5/8"x 3/4" for the inwale. I am thinking of using cherry as I want a fairly tough wood, I like the look of it too. Would this be going too small?
The outwales were 3/16 ash rabbetted out to an L shape so that the sheerline was capped on two sides. I've been using the Huron for several years now with no problems and I'm probably heavier than the average paddler.
PS... I went with 6 oz glass inside and out, and the outside bottom got an extra layer for any abrasion. The last several canoe trips have been kinda rough, dragging the canoe fully loaded over beaver dams and onto shore at campsites so while roughing it out there the extra durability may have done some good. I also thickened the keel line under the stems quite a bit for skid plates, although the wear there is less than I thought it would be.
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Redbird Bernie
- Posts: 28
- Joined: Sun Oct 17, 2010 3:14 pm
- Location: Illinois, USA
Judging by the length of this thread reducing weight is an issue. Unfortunately all our good ideas have no basis in hard facts. Where are all the studies on the characteristics, properties and behaviors of cloth and epoxy layered core materials?
Rather than building something that could ultimately be unsafe, I will opt for the more conservative approach until such time as building techniques and materials are comprehensively tested. Research, in my mind is a time consuming and costly proposition that is best conducted by better equipped technicians rather than one-of builders like me. That is to say, we may be innovators in a lot of ways but are not naval architects. Yes, you guessed it; I just can’t see spending the time getting educated and doing the research for something I didn’t even design but got out of a table. Perhaps one of you would take on the challenge? How about it Glen?
Bernie
Rather than building something that could ultimately be unsafe, I will opt for the more conservative approach until such time as building techniques and materials are comprehensively tested. Research, in my mind is a time consuming and costly proposition that is best conducted by better equipped technicians rather than one-of builders like me. That is to say, we may be innovators in a lot of ways but are not naval architects. Yes, you guessed it; I just can’t see spending the time getting educated and doing the research for something I didn’t even design but got out of a table. Perhaps one of you would take on the challenge? How about it Glen?
Bernie
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Glen Smith
- Posts: 3719
- Joined: Sat May 08, 2004 9:08 am
- Location: Baie-St-Paul, Quebec, Canada
Bernie, perhaps the info at this link would interest you: http://www.thag-o-mizer.net/
Or this one: http://www.guillemot-kayaks.com/Building/Testing/
And also this: http://www.oneoceankayaks.com/Abrasion.htm
And this: http://www.oneoceankayaks.com/Epoxtest.htm
All tests performed by qualified people.
Or this one: http://www.guillemot-kayaks.com/Building/Testing/
And also this: http://www.oneoceankayaks.com/Abrasion.htm
And this: http://www.oneoceankayaks.com/Epoxtest.htm
All tests performed by qualified people.
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BearLeeAlive
- Posts: 196
- Joined: Tue Aug 18, 2009 7:00 pm
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Redbird Bernie
- Posts: 28
- Joined: Sun Oct 17, 2010 3:14 pm
- Location: Illinois, USA
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Bryan Hansel
- Posts: 678
- Joined: Fri May 14, 2004 6:36 pm
- Location: Grand Marais, MN
- Contact:
I wet out all the layers at the same time when using 3.2. It gets a little harder with three layers. For the inside of the boat, I overlapping it like you've described. You end up using less glass, and it's easier to wet-out without getting puddles or floating the glass. It probably stiffens like a rib would, but I can't imagine it adds up to much.Moonman wrote:Hi Bryan,Do you wet out both layers at the same time? I do remember John Winters wrote somewhere that he has used 4oz cloth, laying it perpendicular to the length of the boat, and overlapping it by a few inches as he worked his way down the hull, calling it sort of a 'frame stiffener'.
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Bryan Hansel
- Posts: 678
- Joined: Fri May 14, 2004 6:36 pm
- Location: Grand Marais, MN
- Contact:
If you go with a 3.2, you'd want to lay multiple layers up the sides--inside and out.BearLeeAlive wrote:If I was to use something like the 3.2 oz tight weave, would it be advisable to double it only on the football, or the entire surface? On the inside of the hull, would it also be advisable to double up in the bottom to help support my 220 lb frame?
Depends on your glassing. If you just go with just one layer of 3.2, you might need stronger gunwales.I was thinking 3/8"x3/4" on the outwate, and 5/8"x 3/4" for the inwale. I am thinking of using cherry as I want a fairly tough wood, I like the look of it too. Would this be going too small?
Last edited by Bryan Hansel on Sun Oct 31, 2010 6:31 pm, edited 1 time in total.
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Bryan Hansel
- Posts: 678
- Joined: Fri May 14, 2004 6:36 pm
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- Contact:
These, at least, the ones that I'm mentioning, have been tested and used successfully by a number of builders, myself included. 9.6 oz. of tight-weave glass saves weight because of less epoxy usage. It's just as strong or stronger, because you maximize the fabric to epoxy ratio. And the extra layers work to enhance abrasion resistance. It really comes down to usage.Redbird Bernie wrote:Judging by the length of this thread reducing weight is an issue. Unfortunately all our good ideas have no basis in hard facts. Where are all the studies on the characteristics, properties and behaviors of cloth and epoxy layered core materials
Some resources: This book, although not specifically dealing with wood-strip construction, is gold as far as canoe and kayak building: http://amzn.to/cq2GHB Nick Schade writes about some of these ideas in his new book, Building Strip-planked Boats: http://amzn.to/cwpxc1There are also plenty of good books on the use of composite construction in boat building. If you want specific recommendations, I'll list a few that are on my shelf. There are also a set of scantlings for sale on the Internet that go into this type of construction. Message me if you want a link as he doesn't allow linking to his website.
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Redbird Bernie
- Posts: 28
- Joined: Sun Oct 17, 2010 3:14 pm
- Location: Illinois, USA
Bryan, thanks for the references.
After reviewing the links Glen posted regarding building material testing, it looks like Nick Schade has the most comprehensive data.
The three point testing he had done on 1.5" x 5" samples in a load frame quantifies each sample's relative flexibility and break strength, but is not indicative of hull strength. A more comprehensive approach would have been to test a greater number of samples, use wider samples with an identical number of strips, and test for shear and twist strength. In any case, there seems to be so much variation from one sample to the next that little is to be learned from the data.
The drop weight tests he conducted quantifies peak energy to the ratio of wood to glass and peak energy to panel weigh. The results indicate that double glass on the outside of the hull is advantageous, and that heavier cloth is more impact resistant. Also, the data implies that, for the same glass content, multiple layers of glass at different angles to each other will be stronger than a single layer.
My original goal was to build a light canoe that I could handle even with a bad back, could paddle solo or with a partner. Perhaps I should concentrate on a Rob Roy instead.
After reviewing the links Glen posted regarding building material testing, it looks like Nick Schade has the most comprehensive data.
The three point testing he had done on 1.5" x 5" samples in a load frame quantifies each sample's relative flexibility and break strength, but is not indicative of hull strength. A more comprehensive approach would have been to test a greater number of samples, use wider samples with an identical number of strips, and test for shear and twist strength. In any case, there seems to be so much variation from one sample to the next that little is to be learned from the data.
The drop weight tests he conducted quantifies peak energy to the ratio of wood to glass and peak energy to panel weigh. The results indicate that double glass on the outside of the hull is advantageous, and that heavier cloth is more impact resistant. Also, the data implies that, for the same glass content, multiple layers of glass at different angles to each other will be stronger than a single layer.
My original goal was to build a light canoe that I could handle even with a bad back, could paddle solo or with a partner. Perhaps I should concentrate on a Rob Roy instead.