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Solo expedition build
- Thread starter Alan Gage
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The gunwale width is within 1/4” from front to back. I think the strength from the knuckle has a lot to do with that.
I don't think there will be much, if any, flex in the gunwales unless they're put under a lot of stress. When I was breaking the test pieces the carbon covered cedar looked to have the same amount of flex as the plain cedar, it just took a lot more pressure to get it there.
Thank you, Doug. To me rehabbing an old beat up hull seems like more work in some ways and I've admired some of your restorations. I've done some home remodeling and I've also built new from scratch. To me building from scratch was easier and more enjoyable. Elegantly working with what's already there takes a special mind set that I don't always have.
I'm not planning anything too special here, it doesn't seem like an area that would see very much stress The inwales will butt into the decks and carbon tape will attach them. I'm also starting to give up on the idea of a carry handle integrated to the decks so there will likely be a thwart/handle a couple inches from the deck which, I'd think, would render any weakness in the joint moot.
Well shoot. Here I was thinking maybe I'd try your method next time but....maybe not. Other than those wrinkles in the resin it worked fine but if you had to do a lot of sanding as well maybe it wouldn't be any time saved. I'll have to see if I can come up with a way to keep the peel ply from wrinkling. I think I'll try multiple, short, pieces of peel ply where the shear starts to bend to hopefully make the curve without wrinkles. Or perhaps the woven nylon peel ply will conform better. I'd like to redo the gunnels on my Kite with carbon so I'll have another chance to practice soon.
So am I! I've been starting to think about it quite a bit the last couple days and am really struggling with how I want to do the seat, foot brace, and yolk. I might have to rig up something temporary first just so I can get it on the water and play with different seat heights and positions.
At this point no, not really. I'm trying to keep an eye towards that and will try to integrate anything I can with the seat and foot brace but they're pretty much taking up all of my brain cells right now. I think many of the tie down points will be added after the fact when I figure out what's going to fit where.
A bulkhead behind the seat would be a handy place to mount the rear end of the sliding seat tubes, if I can get them far enough apart to kneel between, and would also make a nice place to attach little things to keep them accessible while paddling. But it also might interfere with my feet when kneeling if too far forward. Need to kneel in one of my other boats and do some measuring.
Yes, I got some good ideas from looking at his outfitting as well as seeing how you've outfitted some of your boats. It looks to be an art form in and of itself. Looking forward to getting over the next couple hurdles and giving it some more thought.
Alan
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A bulkhead works well in some seat configurations and helps stiffen the hull, especially where the seat stresses are most concentrated.
I’ve seen decked canoes with a full cross-section bulkhead that allowed a sliding seat to be height adjusted. That might be an answer to the sitting/kneeling issue.
A test paddle with a temp seat (and gear…and dog) is a good idea.
Was just thinking about the wrinkles. Some of the problem, may have been the difficulty in getting the multiple layers of fabric to lay against the hull, prior bagging.
I noticed Charlie Wilson using a "Industrial Hair Spray" when laying up the cloth in a Placid boat build ! I wonder if something like this would work ? Just a thought !
I realize it was an infusion process, but it might work for our hand layups.
Jim
I noticed Charlie Wilson using a "Industrial Hair Spray" when laying up the cloth in a Placid boat build ! I wonder if something like this would work ? Just a thought !
I realize it was an infusion process, but it might work for our hand layups.
Jim
The fabric itself, once the final fiberglass layer was added, stayed in place pretty well and does not seem to have wrinkled As far as I can tell it was only the peelply that wouldn't conform and left wrinkles of epoxy.
I was wondering the other day how they got the cloth to stay in place when doing a dry layup; the hairspray sounds like a good solution. After adding another layer of glass to a previous coat that was just tacky enough to lightly grab the dry fiberglass I think I'll avoid hairspray for dry layups. It made it difficult to remove the wrinkles as you started rolling and squeegeeing.
Good luck with your fiberglass job today. Can't wait to see it!
Alan
If he was using hair spray or something else in a can it was probably as a mold release. There are PVA and PTFE mold release sprays. West System did a write up about hair spray as a mold release here.
http://www.westsystem.com/ss/mold-re...and-hairspray/
Have you guys thought about using carbon sleeve for covering the gunwales? It would have to be put on off the boat and then slit at the bottom so the gunwale could then slip over the hull.
EDIT: Don't use hairspray to stick layers of cloth together or stick cloth to anything. Hairspray has a water soluble polymer that once dry forms a hard thin plastic. Since epoxy won't bond to plastic it makes it easier to release from the mold. So it works great as a mold release, but if it is sprayed on the fabric you are laminating it will prevent the epoxy from absorbing.
http://www.westsystem.com/ss/mold-re...and-hairspray/
Have you guys thought about using carbon sleeve for covering the gunwales? It would have to be put on off the boat and then slit at the bottom so the gunwale could then slip over the hull.
EDIT: Don't use hairspray to stick layers of cloth together or stick cloth to anything. Hairspray has a water soluble polymer that once dry forms a hard thin plastic. Since epoxy won't bond to plastic it makes it easier to release from the mold. So it works great as a mold release, but if it is sprayed on the fabric you are laminating it will prevent the epoxy from absorbing.
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Sorry Muskrat for the confusion !
I watched Charlie in the video, spray the mold to hold the cloth in the vertical.
He said it was "LIKE Industrial Hair Spray", It was in their Placid boat build video.
Good warning on regular hair spray !
Jim
I watched Charlie in the video, spray the mold to hold the cloth in the vertical.
He said it was "LIKE Industrial Hair Spray", It was in their Placid boat build video.
Good warning on regular hair spray !
Jim
I bet Charlie was using spray tack. Express Composites sells it, and it's purpose is holding dry cloth in place (usually for infusion). I've never used it, but it's my understanding it only works with poly or VE resin.
Muskrat,
I seriously considered CF sleeving, the cost is much lower and there are a wide range of sizes and material combos available. The weave is biased, so the slit sleeving could wrap around compound curves easily.
I couldn't come up with a reliable way to cut the sleeving. I did try with some CF/kevlar sample sleeving, it didn't work out so well. The edges would fray, and I couldn't keep a straight cut line. I thought about some fixturing to precisely slit the sleeving (I am a former toolmaker and current design engineer), but apparently I'm not sharp enough(no pun intended) to do so in a cost/labor efficient manner.
I also considered, as did Alan, using CF sleeving over the gunnel section, allowing the sleeving to tuck up into the sheer line slot like a fat woman's skorts. Again, how to work out any wrinkles while epoxying the gunnel in place??
If you can come up with an ingeneous way to use some sleeving, let us all know, please. It's a stumbling point for me for sure, and many of us might like to use those materials if we could just work out the technique!
With a one piece wood core gunwale like Alan used with the slot that slides over the sheer I would laminate the sleeve onto the gunwale while it was off the boat. After the epoxy was cured or somewhat cured I would then cut the slit out of the bottom, so it could be dropped onto the sheer, but that wouldn't work with a foam core gunwale since the foam doesn't add much strength in bonding to the hull. Most modern windsurf masts are made of carbon and they still have quite a bit of flex. It seems to me without actually trying it that one could still bend it into shape once cured. If it can't, then maybe a crude jig could be made that approximates the sheer curve so that when the gunwale is made up it is cured roughly to the shape of the boat.
The foam core gunwale poses problems for the reasons stated above. Wonderful analogy about the fat woman's shorts. I know exactly what you mean. I'll think on a solution. I'm a horticultural scientist who pretends to know chemistry and fabricating, not exactly an engineer, but I'm decent at coming up with cockamamie schemes with limited materials.
For foam core gunwales done all off the boat. My initial thought is to sleeve like described above and let cure, cut the slot, and then use a strip of carbon or glass tape to shove into the slot, but having the ends of the tape come out of the slot and then immediately turn over to mate with the already cured sleeve. Seems too difficult, unless you had a cedar strip the depth of the slot wrapped in packing tape (mold release) shoved in with the carbon tape, and then with a long skinny bag, vacuum the whole gunwale assembly. Once cured, pull the cedar strip out and then epoxy the gunwale assembly onto the boat.
That's just my initial idea I'll keep thinking on an easier way.
The foam core gunwale poses problems for the reasons stated above. Wonderful analogy about the fat woman's shorts. I know exactly what you mean. I'll think on a solution. I'm a horticultural scientist who pretends to know chemistry and fabricating, not exactly an engineer, but I'm decent at coming up with cockamamie schemes with limited materials.
For foam core gunwales done all off the boat. My initial thought is to sleeve like described above and let cure, cut the slot, and then use a strip of carbon or glass tape to shove into the slot, but having the ends of the tape come out of the slot and then immediately turn over to mate with the already cured sleeve. Seems too difficult, unless you had a cedar strip the depth of the slot wrapped in packing tape (mold release) shoved in with the carbon tape, and then with a long skinny bag, vacuum the whole gunwale assembly. Once cured, pull the cedar strip out and then epoxy the gunwale assembly onto the boat.
That's just my initial idea I'll keep thinking on an easier way.
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It's kind of a fun problem to think through and, like Stripperguy, it's spent plenty of time occupying my thoughts.
I wondered about laying it up on the bench as well and bending it into place afterwards but I had so much trouble getting the one piece cedar gunwale over the hull (I had to cut the ends to separate inwale and outwale) that I don't think you'd be able to do it once it was wrapped in the carbon laminate, it would be much too stiff.
I also thought about making a jig and laying it up pre-bent to make installation easier. But then how to cut the slot in the bottom? Since the gunwale is now bent and curved you can't simply run it through the table saw or router as you would with a straight piece. Letting it green cure and cutting away the laminate over the precut slot with a sharp razor blade is a good idea.
I think the easiest way to do it off boat would be separate inwales and outwales; either laid up straight or pre-bent in a jig. Then epoxied to the hull after setting up hard. It would allow you to use carbon sleeving, which seems to conform to curves and hold shape nicely, hopefully eliminating the need for vacuum bagging. The thinner pieces would hopefully have more flex to be bent to fit the hull. And it should be stronger than a single piece gunwale since with fully wrapped, separate, inwales and outwales you've basically got 4 layers of carbon and 3 cores rather than 2 layers of carbon and 1 core as with the single piece gunwale system. Because of this extra strength you could probably get by with thinner gunwales, making them easier to fit to the hull.
One downside to the above method is figuring out what to do with the now exposed top edge of the hull. I suppose it could be filled flush with black epoxy or it could also make a really neat feature by leaving it natural cedar and topping it with a layer of fiberglass for protection. It would also be a more expensive method since you'd have to buy twice as much sleeving as opposed to a single piece gunwale. Granted the narrow sleeving is cheaper than the larger diameter but not near enough to make up the difference in length required.
I'm anxious to hear what else you come up with!
Alan
I wondered about laying it up on the bench as well and bending it into place afterwards but I had so much trouble getting the one piece cedar gunwale over the hull (I had to cut the ends to separate inwale and outwale) that I don't think you'd be able to do it once it was wrapped in the carbon laminate, it would be much too stiff.
I also thought about making a jig and laying it up pre-bent to make installation easier. But then how to cut the slot in the bottom? Since the gunwale is now bent and curved you can't simply run it through the table saw or router as you would with a straight piece. Letting it green cure and cutting away the laminate over the precut slot with a sharp razor blade is a good idea.
I think the easiest way to do it off boat would be separate inwales and outwales; either laid up straight or pre-bent in a jig. Then epoxied to the hull after setting up hard. It would allow you to use carbon sleeving, which seems to conform to curves and hold shape nicely, hopefully eliminating the need for vacuum bagging. The thinner pieces would hopefully have more flex to be bent to fit the hull. And it should be stronger than a single piece gunwale since with fully wrapped, separate, inwales and outwales you've basically got 4 layers of carbon and 3 cores rather than 2 layers of carbon and 1 core as with the single piece gunwale system. Because of this extra strength you could probably get by with thinner gunwales, making them easier to fit to the hull.
One downside to the above method is figuring out what to do with the now exposed top edge of the hull. I suppose it could be filled flush with black epoxy or it could also make a really neat feature by leaving it natural cedar and topping it with a layer of fiberglass for protection. It would also be a more expensive method since you'd have to buy twice as much sleeving as opposed to a single piece gunwale. Granted the narrow sleeving is cheaper than the larger diameter but not near enough to make up the difference in length required.
I'm anxious to hear what else you come up with!
Alan
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I've been following along quietly (and getting ideas for a solo to be built sometime in the future), and was pondering last night on how to use a CF sleeve for the gunnels. The issue of bending the gunnels once the epoxy has cured sounds like it would eliminate this option.
After reading Alan's last entry, I had a brief flash of inspiration. The gunnel is made of two parts (inner and outer) which are both fairly flexible, and the two gunnels are placed into a CF tube. This tubing is then placed over the top edge of the hull like a pair of saddles bags, so that you've got the top edge of the hull covered by two layers of CF. If the CF tube is sized properly, the top edges of the gunnel pieces should be positioned with the top of the hull. You would then wet out the CF tubing structure with epoxy and vacuum bag the whole shebang to bring it in tight with the hull. I realize I'm making a big assumption with the vacuum bagging - you need to be able to create enough pressure to get the gunnels to curve and conform with the hull shape, and never having used a vacuum bagging system, I'm assuming you could do it. Is this too big an assumption?
After reading Alan's last entry, I had a brief flash of inspiration. The gunnel is made of two parts (inner and outer) which are both fairly flexible, and the two gunnels are placed into a CF tube. This tubing is then placed over the top edge of the hull like a pair of saddles bags, so that you've got the top edge of the hull covered by two layers of CF. If the CF tube is sized properly, the top edges of the gunnel pieces should be positioned with the top of the hull. You would then wet out the CF tubing structure with epoxy and vacuum bag the whole shebang to bring it in tight with the hull. I realize I'm making a big assumption with the vacuum bagging - you need to be able to create enough pressure to get the gunnels to curve and conform with the hull shape, and never having used a vacuum bagging system, I'm assuming you could do it. Is this too big an assumption?
All right I'll give up my idea (for what it's worth). Make the full length gunwale to the correct profile including the slot, preferable from foam but cedar might work as well if the shear isn't too swoopy. Make strips of polyethelyne the same size as the slots the full length of the gunwale. Coat these with mold release. Now slide CF sleeve over the gunwale core leaving it fairly loose and wet it out with epoxy. Next push the poly strips (along with the CF) into the slot, lastly vac bag the whole assembly. Take the whole mess over to the canoe and clamp in place next to the canoe gunwale. Wait a few hours remove from canoe, pull vac bag material and poly off new gunwale. The gunwale profile should match the canoe (close) so that it should be easy to install. Kick back and enjoy.
Some good ideas here, guys. Where's Alan? Are you watching/listening?
I'm always torn by these one off builds...if I did this for a living, I suppose I would have dedicated jigs and fixtures for gunnels and such.
I do like Wysedav's idea of using the sheer line as a form, key is getting the CF (or whatever) to freely slide as it is being wet out.
I'm always torn by these one off builds...if I did this for a living, I suppose I would have dedicated jigs and fixtures for gunnels and such.
I do like Wysedav's idea of using the sheer line as a form, key is getting the CF (or whatever) to freely slide as it is being wet out.
Until you pull the bag and find everything shifted and wrinkled while you were bending it to fit the hull.
Until someone tries it I'm not convinced you can put a carbon sleeve over a straight one piece gunwale, pinch it in place in the slot, and then change the shape without everything getting wonky with you then being unable to smooth the fabric because it's pinched in the slot.
Since Memaquay is laid up and is too much of a masochist to build anything under 75 lbs anyway that leaves it up to Dave or Jim as the only other two currently building that haven't installed gunwales yet. Someone's gotta figure it out and I look forward to seeing your results!
Sleeving seems to be available in heavier weights than tape as well, which would be nice and could eliminate multiple layers if going for more strength, especially when over foam.
My carbon tape is 5.7oz/yd and even with two layers over foam I could feel just a little give when pushing hard with my finger tips. The carbon tape I'm using for thwarts is something like 18oz/yard and is hard as a rock over the foam thwart I made and extremely rigid.
Lots of good ideas floating around here. I'm sure we'll all come away with one or two little tidbits for later use.
Alan
Oh yes, I'm here. Nice weather and long evenings are starting to really take away from canoe building time. Grabbing a quick bite and will head out for a while this evening. The last couple days have mainly been dedicated to building a mold for my seat. Came out pretty well but will need some touchup so, unfortunately, actually forming the seat will probably be a week off. Gotta get back to those decks and get some thwarts installed to get it out for a paddle and test seating positions.
Alan
If I may, I'd like to make a suggestion for someone to try...
What about using a plastic tube, like teflon, cutting a slit in it, and then epoxing it to the hull first. Then wrapping the CF tape or Kevlar over the top of it and down on the hull? Has anyone tried this? Does flexible tube or hose work with epoxy?
Maybe it's a dumb idea. I don't know.
What do you guys think?
What about using a plastic tube, like teflon, cutting a slit in it, and then epoxing it to the hull first. Then wrapping the CF tape or Kevlar over the top of it and down on the hull? Has anyone tried this? Does flexible tube or hose work with epoxy?
Maybe it's a dumb idea. I don't know.
What do you guys think?
