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Building racing canoe: WRC or Composite?
- Thread starter Francis
- Start date
Thanks Alan and Jim to help me in my decisions!
For reinforcements what is the best:?
1) do the bias 'carbon' pieces first before I lay the full fabric on the hull
2) first the carbon fabric over the hull and then the reinforcements (carbon). Aesthetic???
3) step nr 1 + with an extra reinforcement (S-glass) on the delicate places
On almost every place where I'm gonna paddle, there is a dock where I can start and finish, so the 'wings' are my biggest concern.
What do you use to give the carbon some UV protection?
For reinforcements what is the best:?
1) do the bias 'carbon' pieces first before I lay the full fabric on the hull
2) first the carbon fabric over the hull and then the reinforcements (carbon). Aesthetic???
3) step nr 1 + with an extra reinforcement (S-glass) on the delicate places
On almost every place where I'm gonna paddle, there is a dock where I can start and finish, so the 'wings' are my biggest concern.
What do you use to give the carbon some UV protection?
I don't know if the carbon needs UV protection but the epoxy will. Most people over here use a spar urethane (marine varnish) that has some UV inhibitors. I started painting most of mine.
What order to place to reinforcements is personal preference. If you use S-glass for wear protection I think it should go on the outside. If just adding an extra layer of carbon I'd bury it under the main layer but some people like to place it on top of the main layer so they can do a better job of feathering the edge. I don't think you can really go wrong either way.
Alan
What order to place to reinforcements is personal preference. If you use S-glass for wear protection I think it should go on the outside. If just adding an extra layer of carbon I'd bury it under the main layer but some people like to place it on top of the main layer so they can do a better job of feathering the edge. I don't think you can really go wrong either way.
Alan
Yes Alan, I meant protection for the epoxy. For my strippers I've used Epifanes (Marine Varnish), but I've heard that a 2K polyurethane varnish is maybe better...?
First 2 weeks holiday and then we start with the laminating. I'll keep you informed.
First 2 weeks holiday and then we start with the laminating. I'll keep you informed.
Wait, wait, wait!! Don't go on holiday yet.
You said you stapled the Corecell to the molds...Do you plan to remove the staples before you sand and glass? I'm extremely interested to know if your Corecell will hold shape, like wood strips would. You didn't say what brand/type of polyurethane glue you used to hold together the Corecell pieces.
As for heat molding the Corecell, I experimented with using an infrared heat lamp to heat and mold some Divinycell. It worked quite well.
And slightly related (but I want to get this thought out there before it vaporizes)...Has anyone tried a sort of cold molding with wide strips of foam core material? It just occurred to me that the PVC foams are more compliant (complacent?) when wrapping around simple curves. It's the compound curves that require heat molding. Maybe 2 layers of 2-3 inch wide strips laid at alternating 45 degree angles to the keel line.
You said you stapled the Corecell to the molds...Do you plan to remove the staples before you sand and glass? I'm extremely interested to know if your Corecell will hold shape, like wood strips would. You didn't say what brand/type of polyurethane glue you used to hold together the Corecell pieces.
As for heat molding the Corecell, I experimented with using an infrared heat lamp to heat and mold some Divinycell. It worked quite well.
And slightly related (but I want to get this thought out there before it vaporizes)...Has anyone tried a sort of cold molding with wide strips of foam core material? It just occurred to me that the PVC foams are more compliant (complacent?) when wrapping around simple curves. It's the compound curves that require heat molding. Maybe 2 layers of 2-3 inch wide strips laid at alternating 45 degree angles to the keel line.
So, the hull is laminated with plain carbon fabric. I was a little bit worry about the area at the wings, but it was easier then expect. After curing I discovered on a few places bubbles. I have now idea how they came there, because I did the whole laminating with a squeezee and when you push on them there is no air underneath... Unfortunately, no perfect hull possible withe these cosmetic imperfections.
Today almost finished the sanding process for the interior. At this point, I didn't decide how to make my gunnels. I was trying to made them with 2 small Corecell strips glued together, but no it feels as cord, so totally not stiff. OK I have to wrap the carbon around, but I don't know if that gives me the strong gunwales I want. Tips are welcome here.
For the moment, the weight on the scale is 7 kg. I bought some stuff to experiment with the vacuum technique, so another question is: vacuum the inside hull or not...?
Today almost finished the sanding process for the interior. At this point, I didn't decide how to make my gunnels. I was trying to made them with 2 small Corecell strips glued together, but no it feels as cord, so totally not stiff. OK I have to wrap the carbon around, but I don't know if that gives me the strong gunwales I want. Tips are welcome here.
For the moment, the weight on the scale is 7 kg. I bought some stuff to experiment with the vacuum technique, so another question is: vacuum the inside hull or not...?
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Francis,
Fantastic!! Looks great, and I think it will finish very lightweight. 7 kg is great for that length hull. My 14'6" Kite was about that weight at the same point in my build.
Now, back to my questions from before your holiday.
What glue did you use on the Corecell foam?
When you removed your staples, did the foam hold shape?
As for your Corecell gunnels, if you attach 2 of those two layer pieces to the hull and glass wrap them, maybe 2 layers of 4 oz glass, you should have a strong enough gunnel. The strength will come from the section thickness, just the same as the hull.
If you use carbon fiber to wrap the foam, that carbon would likely soak up much resin, and add more weight than you'll be happy with.
Vacuum or not? Vacuuming will definitely give you less excess resin, and less weight. It would also insure that the inside cloth is firmly in contact with the foam. Hand laminating will be messy for sure, and you may have trouble to get a superior lamination.
Fantastic!! Looks great, and I think it will finish very lightweight. 7 kg is great for that length hull. My 14'6" Kite was about that weight at the same point in my build.
Now, back to my questions from before your holiday.
What glue did you use on the Corecell foam?
When you removed your staples, did the foam hold shape?
As for your Corecell gunnels, if you attach 2 of those two layer pieces to the hull and glass wrap them, maybe 2 layers of 4 oz glass, you should have a strong enough gunnel. The strength will come from the section thickness, just the same as the hull.
If you use carbon fiber to wrap the foam, that carbon would likely soak up much resin, and add more weight than you'll be happy with.
Vacuum or not? Vacuuming will definitely give you less excess resin, and less weight. It would also insure that the inside cloth is firmly in contact with the foam. Hand laminating will be messy for sure, and you may have trouble to get a superior lamination.
At this Stage in the game.
I'd be afraid to pull a vacuum on that hull, in fear of deforming it ? More a question than a fear !
I may be wrong as this is way different, than what I do. 7kg = 15+ #. That is light.
Are you going to glass over the Carbon ???? That will increase weight, but add a lot of durability. S-glass, if you can get it !
I'd go with a layer of S-glass on the inside, 6 oz also ???
I'd even use S-glass to wrap the gunnels, over carbon.
Fun build thread for sure !
Thanks Francis !
Jim
I'd be afraid to pull a vacuum on that hull, in fear of deforming it ? More a question than a fear !
I may be wrong as this is way different, than what I do. 7kg = 15+ #. That is light.
Are you going to glass over the Carbon ???? That will increase weight, but add a lot of durability. S-glass, if you can get it !
I'd go with a layer of S-glass on the inside, 6 oz also ???
I'd even use S-glass to wrap the gunnels, over carbon.
Fun build thread for sure !
Thanks Francis !
Jim
Here a picture of the glue I use for the Corecell. It's more messy then wood glue and it's also very difficult to clean the seams when they are still wet. The glue expand in his drying process, so for the outside I wait a little bit (curing time 10 minutes) and then with a Stanley knife I clean it up. For the inside of the hull was that no so easy...
Thanks for the suggestions about the gunnels, but still a few questions. So for the next step after sanding the inside:
1) laminating the inside with the carbon
2) install the gunnels. If I make the gunnels, how can I keep them straight when I laminate them, or glue the gunnel to the hull and them cover them?
Or do I first glue the gunnels to the inside and then laminating them in one shot when I laminate the inside hull?
The easiest way is install wooden inside gunnels, but then I made the total weight more. It's difficult to find the balance between 'light' and 'stupid light'.
As I said, no with 2 strips for the gunnels, it feels as I have a rope in my hand. What kind of sizes has yours gunnels in foam?
Thanks for the suggestions about the gunnels, but still a few questions. So for the next step after sanding the inside:
1) laminating the inside with the carbon
2) install the gunnels. If I make the gunnels, how can I keep them straight when I laminate them, or glue the gunnel to the hull and them cover them?
Or do I first glue the gunnels to the inside and then laminating them in one shot when I laminate the inside hull?
The easiest way is install wooden inside gunnels, but then I made the total weight more. It's difficult to find the balance between 'light' and 'stupid light'.
As I said, no with 2 strips for the gunnels, it feels as I have a rope in my hand. What kind of sizes has yours gunnels in foam?
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My foam gunnels were the same floppy noodles as yours before I epoxied them in place and laminated them
if you’re unsure make a sample section of hull and gunnel and test it out
no need to experiment on your hull do it on a sample piece
i think my gunnels were about 1-1/8” x 1” with a deep slot cut to fit over the hull
it was difficult and time consuming to laminate them in place on the hull
someone on this forum made laminated gunnels on temporary forms next to their hull and the gunnels came out great
i can’t remember which member but maybe they will chime in
if you’re unsure make a sample section of hull and gunnel and test it out
no need to experiment on your hull do it on a sample piece
i think my gunnels were about 1-1/8” x 1” with a deep slot cut to fit over the hull
it was difficult and time consuming to laminate them in place on the hull
someone on this forum made laminated gunnels on temporary forms next to their hull and the gunnels came out great
i can’t remember which member but maybe they will chime in
I'd laminate the inside first, then add the gunnels.
If you don't plan to hang your seats from the gunnels,( most racing canoes don't ) You won't need a real stiff gunnel.
Alan Gage has a neat seat design you might like. I tried to locate it. Maybe he will chime in ! Or PM him.
Jim
If you don't plan to hang your seats from the gunnels,( most racing canoes don't ) You won't need a real stiff gunnel.
Alan Gage has a neat seat design you might like. I tried to locate it. Maybe he will chime in ! Or PM him.
Jim
I love wood canoes and have paddled a 1951 OT Guide for 30 years. But for racing I would build one out of kevlar. More complex shapes are possible with more sheer entry lines.
They generally use a wood strip hull to create the composite mold so I'd say you can get the same shapes from wood.
Alan
Here an update of the C1 racing canoe I build with Corecell and carbon fiber. The laminating of the inside was a little bit tricky. I had cut the carbon so I could lay them from gunwale to gunwale. and did the wet-out on a plastic sheet and then with some extra hands, lay them in the hull. With a squeegee I removed the extra epoxy, but after curing I had stille a few bubbles. Maybe next time it's better to vacuum bag the inside. A week ago I did already a test with the C1 and I'm very happy with the performance! I had installed a temporary footbar system, but today I glued the L-profiles. I made the gunwales with 2 strips of Corecell and then wrap them with Carbon tape. I was a little bit worry about that, but the result is very stiff.
I wet-sanded the outside and have a very dull result (see picture). Can I do something extra to prepare the hull before I'm gonna apply the 2K clear coat varnish?
I wet-sanded the outside and have a very dull result (see picture). Can I do something extra to prepare the hull before I'm gonna apply the 2K clear coat varnish?
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I have a hard time wetting out carbon also.
Seems like air likes to hide in the weave.
Now that you've completed your third racer, tell us how it compares in weight against your first two !
An do you think made the biggest difference ! ?
How would you build your 4th racer ?
Jim
Seems like air likes to hide in the weave.
Now that you've completed your third racer, tell us how it compares in weight against your first two !
An do you think made the biggest difference ! ?
How would you build your 4th racer ?
Jim
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