May be of interest,
40 lb Osprey
http://www.myccr.com/SectionForums/view ... hp?t=10546
Doug
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How Succesful was you lightweight attempt?
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Bryan Hansel
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Sluggo,
The epoxy-wood flour stem would probably be easier to fix since any gouge or dent could simply be filled in with more mix. I used epoxy and chopped fiberglass since the strength vs weight should be greater.
During construction, I weighed the hull at various points and the epoxy and glass sheathing only contributed about 15% to the total weight. All the rest was in wood and hardware, so IMO, that's where the greatest weight savings would probably be.
The epoxy-wood flour stem would probably be easier to fix since any gouge or dent could simply be filled in with more mix. I used epoxy and chopped fiberglass since the strength vs weight should be greater.
During construction, I weighed the hull at various points and the epoxy and glass sheathing only contributed about 15% to the total weight. All the rest was in wood and hardware, so IMO, that's where the greatest weight savings would probably be.
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Bryan Hansel
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s - I think he was just describing using a real thin layer of sawdust and epoxy to come up with a skid plate. I've done something similar using graphite and epoxy on my Bell Magic. It worked for a couple of trips, but I was unimpressed and have not refinished it that way. The advantage would be that it would be easy to repair.
For all but one of my boats, I've left out both the inner and outer hardwood stem and just added extra glass to the stems. Not sure about weight savings, because I've never actually weighed it, but I believe that there is a significant weight savings between 3 and 4 pounds.
If I wanted a skid plate on one of my boats, I'd just add extra glass or dynel coated in graphite and epoxy as described on the clc site: http://www.clcboats.com/shoptips/shoptips_rubstrips.php. This style of skid plate will provide more protection at little extra weight over wood flour and epoxy.
But the wood flour and epoxy seems to work for Jay. This last summer he paddled one of his lightweight canoes from the St. Lawrence Seaway to Lake Winnipeg, and the boat held up just fine.
I agree with Rick about where weight savings is at.
For all but one of my boats, I've left out both the inner and outer hardwood stem and just added extra glass to the stems. Not sure about weight savings, because I've never actually weighed it, but I believe that there is a significant weight savings between 3 and 4 pounds.
If I wanted a skid plate on one of my boats, I'd just add extra glass or dynel coated in graphite and epoxy as described on the clc site: http://www.clcboats.com/shoptips/shoptips_rubstrips.php. This style of skid plate will provide more protection at little extra weight over wood flour and epoxy.
But the wood flour and epoxy seems to work for Jay. This last summer he paddled one of his lightweight canoes from the St. Lawrence Seaway to Lake Winnipeg, and the boat held up just fine.
I agree with Rick about where weight savings is at.
Here are some more thoughts on trying to build a lighter canoe. I'm trying to put together some of the ideas and techniques other people use.
3/16" WRC strips
4oz s-glass cloth inside, no fill coats
6oz e-glass loose weave for outside (gives a nice clear wetout).
4oz s-glass on outside football
WRC outside gunwale
hardwood inside gunwale with slots, is hardwood better for attaching seats or thwarts? Otherwise WRC on inside too. I'm not too interested in chasing down Sitka spruce
cedar thwart
I like the idea of a 1-piece WRC gunwale, but I'm not sure about attaching the thwart and seats. I need to find more info on this.
Would this produce a "light-weight" canoe? I guess it's all kind of relative...
3/16" WRC strips
4oz s-glass cloth inside, no fill coats
6oz e-glass loose weave for outside (gives a nice clear wetout).
4oz s-glass on outside football
WRC outside gunwale
hardwood inside gunwale with slots, is hardwood better for attaching seats or thwarts? Otherwise WRC on inside too. I'm not too interested in chasing down Sitka spruce
cedar thwart
I like the idea of a 1-piece WRC gunwale, but I'm not sure about attaching the thwart and seats. I need to find more info on this.
Would this produce a "light-weight" canoe? I guess it's all kind of relative...
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Bryan Hansel
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Depending on the glass, you can wet out a satin weave clear. Consider that for your outside layer. It will hold less epoxy.
For attaching seats some people on the board use cleats epoxied to the hull. Bell Canoe Works does this on their lightweight hulls with metal cleats and rivets, but there is no reason you couldn't do it with wood.
I'd add "No hardwood stems."
For attaching seats some people on the board use cleats epoxied to the hull. Bell Canoe Works does this on their lightweight hulls with metal cleats and rivets, but there is no reason you couldn't do it with wood.
I'd add "No hardwood stems."
Bryan's point about no hardwood stems will reduce the build time as well, since lighter stems will also be easier to form to the proper shape. The epoxy, glass and wood flour on the outer stem will hide the appearance of the wood so an expensive hardwood there won't be necessary.
My outwales were ash, while the inwales were softer white pine. The outwales take a lot of abuse, so I felt the more durable (and heavier) ash was justified. The outwales were rabetted out to an "L" cross section and 3/16" thickness for lightness while still retaining structural rigidity. The soft white pine inwales held screws well enough and support weight with no problems so far (two years of use).
WRC outwales will be soft and dent easily, so maybe a layer of glass could increase their durability while still keeping things light... just some thoughts.
My outwales were ash, while the inwales were softer white pine. The outwales take a lot of abuse, so I felt the more durable (and heavier) ash was justified. The outwales were rabetted out to an "L" cross section and 3/16" thickness for lightness while still retaining structural rigidity. The soft white pine inwales held screws well enough and support weight with no problems so far (two years of use).
WRC outwales will be soft and dent easily, so maybe a layer of glass could increase their durability while still keeping things light... just some thoughts.
I'm wondering if anyone has any special tricks, besides just experience, in getting a nice even coat of epoxy for just one coat on the inside. This of course would save a couple pounds. On my last boat, I wanted to try and do this but my efforts were uneven, and as stated in Canoecraft, an uneven coat doesn't look that good. I had to lay on another coat to even things out.
Moonman.
Moonman.
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Erik, Belgium
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- Location: Gierle, Belgium
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Ah, there 's a lot to write about how to do a nice even layout of glasscloth. I 'll try to keep it short.
Situation: hull scraped and sanded. Holes filled and ready to go. Here 's what I usually do:
First, you could do a first saturation coat on bare wood (I 've done it only for my latest layup, and for me it 's worth it for several reasons). Sand smoothly when tackfree and
Secondly: lay the cloth on the hull with latex gloves. As few (NO !!) wrinkels and (NO !!) tearing as possible. Lay the glas on correctly the first time. Then take a wide painter brush and wipe all uneven areas flat to the hull. Let is lay down like that for the night (to sack out).
Thirdly: apply epoxy with rollers. Roll it out on the glasscloth, use ONLY fresh epoxy and avoid to regain any airfullied wipeoff's. When the hull is fully epoxied (say 40' till 1 hour), I take my squeegee and gently force it towards the hull, removing all excess epoxy. Throw away this epoxy (don 't reuse it to wet-out !).
Avoid any tearing with the glasscloth (dry or wet).
Erik, Belgium.
Situation: hull scraped and sanded. Holes filled and ready to go. Here 's what I usually do:
First, you could do a first saturation coat on bare wood (I 've done it only for my latest layup, and for me it 's worth it for several reasons). Sand smoothly when tackfree and
Secondly: lay the cloth on the hull with latex gloves. As few (NO !!) wrinkels and (NO !!) tearing as possible. Lay the glas on correctly the first time. Then take a wide painter brush and wipe all uneven areas flat to the hull. Let is lay down like that for the night (to sack out).
Thirdly: apply epoxy with rollers. Roll it out on the glasscloth, use ONLY fresh epoxy and avoid to regain any airfullied wipeoff's. When the hull is fully epoxied (say 40' till 1 hour), I take my squeegee and gently force it towards the hull, removing all excess epoxy. Throw away this epoxy (don 't reuse it to wet-out !).
Avoid any tearing with the glasscloth (dry or wet).
Erik, Belgium.
Thanks Erik,
Sealing the inside is something I was thinking about. You can get a nice light coat, then sand it to even out any bumps etc.
Then your one wetout coat wil not sink in in some areas more than others, due to uneven application. And then you can still get that nice matte finish.
I think I just might do this on my next boat.
Moonman
Sealing the inside is something I was thinking about. You can get a nice light coat, then sand it to even out any bumps etc.
Then your one wetout coat wil not sink in in some areas more than others, due to uneven application. And then you can still get that nice matte finish.
I think I just might do this on my next boat.
Moonman
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Erik, Belgium
- Posts: 344
- Joined: Fri May 14, 2004 5:31 am
- Location: Gierle, Belgium
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For steap areas on the inside (near the stems) I always use another trick: I apply a think coating with thickened epoxy near the stems (at least one foot). I let it cure a bit (15') and then gently place the glasscloth against the thickened epoxy. Here also: try to place the glass on the right place from the 1st time, don't tear it off again.
Because it is thickened it will NOT fall off, NOR will airbubbles appear under the glass.
my 2 Belgian eurocents
Erik, Belgium.
Because it is thickened it will NOT fall off, NOR will airbubbles appear under the glass.
my 2 Belgian eurocents
Erik, Belgium.
Sealing the hull
Moonman, many of the experienced builders feel that sealing is a waste of time and epoxy. I think sealing is great for a couple of reasons: 1st, sealing fills in those fine gaps between the strips ( there are always some as it's hard to avoid). This reduces the chance of those pesky little air bubbles that popup about 2 hours after you've gone inside for dinner.
2nd, after buffing the seal coat with a Scotch Brite pad (green or red), I feel that the glass cloth is easier to lay on and smooth out as Erik explains.
3rd, the wetout coat takes less epoxy. I only use a seal coat and a stop with after a good wet-out coat on the inside of the hull then varnishing with a matt varnish. The texture is non-slip and anti-glare and this saves a pound or two of weight.
Ed...
2nd, after buffing the seal coat with a Scotch Brite pad (green or red), I feel that the glass cloth is easier to lay on and smooth out as Erik explains.
3rd, the wetout coat takes less epoxy. I only use a seal coat and a stop with after a good wet-out coat on the inside of the hull then varnishing with a matt varnish. The texture is non-slip and anti-glare and this saves a pound or two of weight.
Ed...
Ed Alger
Hi Ed,
Yeah, sealing the inside is one of the somewhat controversial topics. I know John Michne's points and I know the other points as you've outlined.
It think it honestly comes down to what you're comfortable with and what has worked for you in the past. Its hard to argue with a guy who has done it one way or the other and had great success. And as we know, both methods have produced beautiful hulls.
Thats the beauty of boat building - having a problem or issue, coming up with a solution that works for you, then trying it out, evaluating and perhaps keeping that method or altering a bit on the next project.
I find on my first boat, some of the most satisfying moments were the times I reached an impasse due to some stupid mistake or other and then sitting there in my moaning chair, as Ted calls it, and figuring out a solution. I think with our modern lives and consumer society, we've lost that masterful feeling of self accomplishment when finally solving a building problem or fixing a screw-up.
Peace,
Moonman.
Yeah, sealing the inside is one of the somewhat controversial topics. I know John Michne's points and I know the other points as you've outlined.
It think it honestly comes down to what you're comfortable with and what has worked for you in the past. Its hard to argue with a guy who has done it one way or the other and had great success. And as we know, both methods have produced beautiful hulls.
Thats the beauty of boat building - having a problem or issue, coming up with a solution that works for you, then trying it out, evaluating and perhaps keeping that method or altering a bit on the next project.
I find on my first boat, some of the most satisfying moments were the times I reached an impasse due to some stupid mistake or other and then sitting there in my moaning chair, as Ted calls it, and figuring out a solution. I think with our modern lives and consumer society, we've lost that masterful feeling of self accomplishment when finally solving a building problem or fixing a screw-up.
Peace,
Moonman.