Carbon Fiber Nokomis

[Muskrat]

Sounds like a good sturdy layup. I like the thin layer of glass on the inside. Gives you something to sand into without immediately fuzzing the kevlar.

How do you attach your shrink film to the mold? That was always a pain when I did it. The best solution I came up with was attaching a wood strip all along the underside of the stations, one on each side, and then attach double stick tape the whole length. I also put a strip of double stick tape down the keel. With help I'd stretch and lay out the film over the length of the boat and then run down the length and attach to the bottom of the mold. For the stems which I attach last, I leave a section of double stick with the paper on until everything else is in place, then stretch the film over from one side, trim, apply another strip of tape, pull the other side of the shrink over and stick it, and one final trim.

Thats a long winded response, hope it makes sense. It also a little late, but for anyone else or if you do it again sometime, it will make a wrinkle free mold release wrap. And, Duck brand is the only film I will use.

 

[Quinn]

I might put the carbon somewhere else (but I'm also not an expert by any means). By putting it in the middle of your layup you'll get the least stiffness from it, and stiffness is often the main advantage of carbon. Carbon is pretty strong and stiff to go in the middle of a layup where it won't see much stress.

 

[Muskrat]

I think the carbon is in the right place for a work boat so to speak. The s glass is on the outside for good abrasion resistance, and the kevlar on the interior for tension and to prevent catastrophic failure. The 6 oz glass on the outer layer could be rid of for a lighter weight boat or could be swapped for a layer of 4 oz just for the abrasion. The carbon's innate stiffness won't change based on where it is in the layup. Carbon is king in compression resistance, but in my opinion the abrasion resistance of the s glass is more important for a canoe that will probably take more grinds than impacts. I'm assuming the rivers in Iowa are similair to the ones in Kansas and Nebraska I've floated, in which you're more likely to grind to a halt on a sandbar "turtle" than smash into something hard like a chunk of granite.

Edit: Quinn, I'm not trying to sound contrary, I think you're generally correct. Carbon theoretically performs best on the outer layer, especially when making the lightest and strongest layup.

 

[Jim Dodd]

Sounds like a good sturdy layup. I like the thin layer of glass on the inside. Gives you something to sand into without immediately fuzzing the kevlar.

How do you attach your shrink film to the mold? That was always a pain when I did it. The best solution I came up with was attaching a wood strip all along the underside of the stations, one on each side, and then attach double stick tape the whole length. I also put a strip of double stick tape down the keel. With help I'd stretch and lay out the film over the length of the boat and then run down the length and attach to the bottom of the mold. For the stems which I attach last, I leave a section of double stick with the paper on until everything else is in place, then stretch the film over from one side, trim, apply another strip of tape, pull the other side of the shrink over and stick it, and one final trim.

Thats a long winded response, hope it makes sense. It also a little late, but for anyone else or if you do it again sometime, it will make a wrinkle free mold release wrap. And, Duck brand is the only film I will use.

The double sided tape, worked great to suck the film in at the tumblehome.
I tried attaching the film to just the forms, but had way too many wrinkles. I used short pieces of packaging tape about every 6", and then taped the full length with wide overlapping packaging tape.

My method could easily use improvement ! I like the strip idea ! NEXT TIME !! Thanks !

The Duct brand worked ! The other didn't.

I have enough 4 oz E-glass for inner and outer layers, and could swap the 6 oz. Maybe I'll throw a quick test together.
Thanks !

Jim

 

[Alan Gage]

Your window film looks great. When are you hoping to start laying up? Too bad this warm weather couldn't have lasted another week.

Plan is to lay 4 oz E-glass on and wet out. I will let it set, then apply 5 oz Kevlar. Next will go 5 oz Carbon Fiber. A layer of 6 oz E-glass. Lastly a 9 oz layer of S-glass to about the 3 or 4" waterline.

Will you be doing your cedar strip core again after it comes off the mold or will it be a solid laminate? If no core I'm a little concerned you might not have enough layers for a stiff enough bottom.

From what I've read I also tend to agree with Quinn about the placement of the Carbon if you're not using a core. I don't have any real world experience but from what I read and understand the layers in the middle of the laminate don't aid as much in stiffening as opposed to being closer to the outside. I like the idea of protecting the carbon with fiberglass but wonder if it's not buried a little too deep.

It took 10 bottom layers on my tandem for it to feel as stiff as that fiberglass Wildfire I picked up at the auction. Of course it's a lot wider and flatter bottomed and I'm also trying to judge the stiffness by hand only. Right now my composite Bloodvein has, on the bottom, a layer of 6oz. s-glass, 6oz. carbon, and 5oz. kevlar with one more partial layer of carbon under the seating area and running up the sides. Hopefully I'll pull it off the mold this weekend. I'll be adding more layers to the inside but am curious to see how stiff the current layup feels on a narrower and more rounded hull shape.

Of course all this gets a disclaimer that none of my composite hulls have touched the water yet so what do I know. And you've already built two of them. Think I'll be quiet now.

Alan

 

[Muskrat]

I think this layer order gets a little blown out of proportion. Consider that a single layer of fabric is 0.008 to 0.017 inches thick. All five of Jim's layers will be about 0.050 inch thick. The compressive and tensile forces from inside to out of that panel would be much different than a panel with a 0.250" core. Layup up a panel with a core material, kevlar on one side and carbon on the other. That panel will fail at different degrees of force applied depending on which side is on the outside of the bend. Do the same with only a layer of carbon and kevlar, no core, about .020" and you probably won't notice the difference.

Regardless of all that, Jim was going to use a 0.125" cedar core. 0.02 inches from the outside puts that carbon layer well away from the center of the laminate.

 

[Alan Gage]

Regardless of all that, Jim was going to use a 0.125" cedar core. 0.02 inches from the outside puts that carbon layer well away from the center of the laminate.

Agree if he's using the core. I thought perhaps he'd changed is mind and was going with a solid laminate.

Alan

 

[Jim Dodd]

I really like a wood core ! In the last build, the WRC core was 1/8". I'm thinking I can reduce this even more. Plus a layer of 4 oz E-glass on top of this.

I didn't realize the S-glass was soo heavy. 9 oz. I could opt for 6 oz E-glass ?

Thoughts ?

Jim

 

[Jim Dodd]

Will you be doing your cedar strip core again after it comes off the mold or will it be a solid laminate? If no core I'm a little concerned you might not have enough layers for a stiff enough bottom.

It took 10 bottom layers on my tandem for it to feel as stiff as that fiberglass Wildfire I picked up at the auction. Of course it's a lot wider and flatter bottomed and I'm also trying to judge the stiffness by hand only. Right now my composite Bloodvein has, on the bottom, a layer of 6oz. s-glass, 6oz. carbon, and 5oz. kevlar with one more partial layer of carbon under the seating area and running up the sides. Hopefully I'll pull it off the mold this weekend. I'll be adding more layers to the inside but am curious to see how stiff the current layup feels on a narrower and more rounded hull shape.

Of course all this gets a disclaimer that none of my composite hulls have touched the water yet so what do I know. And you've already built two of them. Think I'll be quiet now.

Alan

With a funeral Saturday (temperature is going to make that brutal) Thinking I better wait some.

Alan, I'll patiently wait until you pull the Bloodvein Composite off. I too am anxious to here about it's stiffness. Hoping to gain more info from you, on the weight as well as rigidity.

When we finish these, We'll have to have a contest ! Ha !

Jim

 

[Alan Gage]

From what I can tell on some composite hulls no external fiberglass isn't uncommon, a layer of 6oz. e-glass is standard, and a layer of 6oz. s-glass is the upgrade.

Alan

 

[Quinn]

I'd make test pieces before deciding on a layup. A while ago I made 4 note card test pieces of 9 oz glass and Polyester. They were all vac bagged at once, so they had very similar resin content. From the outside in they where: g/g/p/p, g/p/g/p, p/g/g/p, and g/p/p/g. g/p/p/g was by far the stiffest, and the difference between it and p/g/g/p was significant. All had varying properties in terms of ultimate strength and impact resistance.

 

[Jim Dodd]

I'd make test pieces before deciding on a layup. A while ago I made 4 note card test pieces of 9 oz glass and Polyester. They were all vac bagged at once, so they had very similar resin content. From the outside in they where: g/g/p/p, g/p/g/p, p/g/g/p, and g/p/p/g. g/p/p/g was by far the stiffest, and the difference between it and p/g/g/p was significant. All had varying properties in terms of ultimate strength and impact resistance.

You've convinced me ! I'll put some to a test.

Stiffness is a priority, as well as durability. I'll throw in looks also.

I'm seeing the light of testing especially now, that I've recently done a little !

Thanks !

Jim

 

[Alan Gage]

Savage river gives a rough idea of their different layups in terms of cloth type, number of layers, and core thickness. No doubt they're more involved than the brief website descriptions but it's interesting none the less. Scroll to the bottom.

http://www.savageriver.com/canoes/racing/blackwater

Alan

 

[Jim Dodd]

Wow ! They are really light ! Wonder how stiff the sides are, with so little cloth ?

I can see I need to drift away from Ash gunnels !

You are going to have to school us on the carbon gunnels !

Thanks for the link, on this cold Winters day Alan !

Jim

 

[Jim Dodd]

It's been crazy around here, but I made it down to the shop. Cut a few scraps for a test.

Brought home three scraps. one 4 oz E-glass, 6 oz E-glass, and a piece of 9 oz S-glass here's a pic in the above order

Decided to mic their dry thickness.
4 oz E-g= .006"
6 oz E-g=.009"
9 oz S-g=.011"

The 4oz is quite drapable, and a tighter weave than the 6oz.

The 9 oz S-glass is dense, very tightly woven. Good thing, I'm only using it on the flat, and just below the water !

I thought I could go one of two routes. Two layers of 6 oz, which would= .018" or or one layer of 4 oz E-g and one of 9 oz S-g.this equals .017".

The only thing I'm slightly concerned about is the 9 oz S-glass appearing cloudy over the Carbon Fiber.

Hoping for some thoughts !

Jim

 

[Alan Gage]

I put one partial layer of 6oz. s-glass on the outside of my Bloodvein. After the fill coats the carbon under the s-glass looked good as long as you didn't compare it to the areas that weren't covered by s-glass, they had more pop. Not a deal breaker for me though. I don't know how much cloudier it would be if thicker.

Looking like a warm up towards the end of the week. Think you'll be ready to lay down some cloth by then? I know I will be.

Alan

 

[Jim Dodd]

Today I was back at CF Nokomis, and wetted the Carbon fiber on top of the previously cured Kevlar, from yesterday.
I will post pics tomorrow, along with three mistakes I made, nothing major.

So in lieu of pics, here is a cool You Tube vid.

Jim

 

[Alan Gage]

That is a cool video but, COME ON MAN! We need some pictures! Don't tease us like that.

BTW, that video is exactly what I look like working in my shop. Everything is neat, clean, and orderly. Everything is meticulously measured and laid out and nothing ever goes wrong. And never any cursing either.

Looking forward to pics tomorrow.

Alan

 

[Jim Dodd]

OK !

This build has it's share of problems, Builder generated!
I'll throw some pics to start.

Seriously thinking of bigger batches, but my Ducks are all lined up. It does save time to have most of my cups already loaded. I warm the resin slightly while mixing. Each batch gets mixed at least 3 minutes.

First big mistake ! Kevlar wasn't wide enough, nor long enough. Builder Error !!

Error #2, I should have trimmed the CF Before wetting out. It would have made the scraps a lot more usable !

Loved wetting out the 6 oz E-glass over the CF ! Unlike wetting out the Kevlar, and the CF, it was obvious, if I had enough resin on the cloth.

Peel Ply on the stems.
One more layer, the 9oz S-glass, up to about the 3 or 4" waterline. Then finish the fill coats.

All in all, I'm excited about my next CF. I know I have a ways to go on this one, but basically I'm pleased !

Thanks Alan ! OH and Muskrat !

Jim

 

[Canotrouge]

Nice looking layup!! I guess if we didn't make mistake we wouldn't learn and it could get boring quick!! Or not!