basalt Innegra tandem tripper.

[Mp214parks]

Hello all. I’m new here. I’m just getting started on my next canoe build. And it looks like you guys are a gold mine of composite info. I’m still reading through all the composite build threads, so I’ll keep the questions down for now.
I have finished my mold. It’s cedarstip, mud, and paint. I’m thinking I’ll coat it in window shrink wrap for a release. As of now, my layup plan inside to out is 5 oz carbon, 3 oz plain Innegra, 7 oz basalt Innegra, 3 oz s glass. I will trim it with dyvinicell foam enclosed in carbon sleeves. I realize this might not be the litest option, but it should give it a really clean look.

The purpose of this boat boat is to race in the Yukon 1000. I’ve ran it twice before. It’s a design I tweaked from several others. It’s 17’6” x30.4” at the 4” waterline. The goals of the layup are:
liteweight, rigid, clean. The goals of the boat are: efficient, seaworthy, lite.

 

[Jim Dodd]

AWESOME !

Oh if I was 40 yrs younger, and lived in Alaska !!!

Carbon gave me fits wetting it out, so be careful. I was working by myself, and only put one layer on at a time, waiting until it cured past tacky. The problem was, I couldn't tell if it was wetted properly !

Others put several layers at a time on. They may be more experienced than me, and also used a slower setting epoxy ! I sure could have used an extra hand ! ( I will next time)

Had a very tight weave S-glass, 6 oz, that was also difficult, but manageable.

The heat shrink plastic works great, except if you have Tumblehome !

In my Black Pearl thread, I show how I managed that, and it worked ! I will do this on my next composite also !

I'm excited to follow along !

Jim

 

[Jim Dodd]

Your Male mold looks great !

The window film will make up for some rough spots in the hull. Not that it matters, as it is the inside of the hull !

Jim

 

[Mp214parks]

Well that’s one of my quandaries... I do have tumblehome at the paddleing stations. I was Planning to get the fabric to stick to the mold at tumblehome areas by clamping on the pre made gunwales after doing a complete layup in one sitting. I have two somewhat experienced buddies to help. And of course it’s easy enough to have a cool shop. Not sure if thats too ambitious. It seems like a worst case scenario would be if my fabric starts getting stiff two or three layers in, I could tape my gunwales with packaging tape and clamp them on temporarily to hold the fabric to the mold at the gunwales. At any rate, I need to get that fabric to hold to the form.

To make my gunwales, I plan to package tape my mold at the gunwale line. Then wet out my gunwales and clamp them on using a cedar batten which is also taped. I’ve never used peel ply and I’m a little nervous to start.

 

[Jim Dodd]

The plastic I used worked great ! Tipping the hull helped a lot also. The first layer was wet out, one side at a time. I let the first side cure over night. Leaving the clamped plastic on, then tipped the mold to the other side, and wet that side out ! No problem where the to edges met at the keel.

The plastic I used was the kid painters use for painting around trim. A little thicker than a plastic jug.

Check my photos, at my Black pearl thread.

Jim

 

[dougd]

If you're using Peel Ply make sure it's the correct kind. My first order I bought Peel Ply that had to be lifted off after 2 hours, it's green in color. A hard mistake to learn from! The other is blue and can be left on for long periods of time.

https://www.jamestowndistributors.c...3754&familyName=Vacuum+Bagging+Release+Fabric

The mold looks great!

dougd

 

[Guest]

If you're using Peel Ply make sure it's the correct kind. My first order I bought Peel Ply that had to be lifted off after 2 hours, it's green in color. A hard mistake to learn from! The other is blue and can be left on for long periods of time.

Some Release Treated peel ply is white, and looks almost like lightweight glass cloth. I have not noticed a difference between the blueish stuff and the white.

The Green Pull peel ply has it's place. Just not in my shop.

 

[Mrindy]

Oh man, this is going to be a fun build to watch! I made a carbon fiber Innegra last summer based on an 18 foot Jensen. The tumblehome looks very similar to your plug (not as extreme as Jims) and I think you could get it in one go. It was my first time using peel ply and what a game changer. I felt like it helped tack the fabric down better, especially on the gunwales. Similar to your plan, I also had backup strips wrapped in plastic ready to clamp on the gunwale line if needed.

I am not an engineer by trade but have read that the CW is to have the stiffest materials on the outside and the more flexible materials on the inside to improve efficiency and provide more impact resistance. Given the materials, maybe switch the carbon and basalt Innegra layers? Someone with more knowledge or experience may be able to confirm or refute that. I have also read that pure Innegra floats on resin and is a bit squirmy so sandwiching it seems like a good idea.

Im intrigued by your gunwale plan! Are you doing 2 gunwales wrapped in sleeve or a uniwale?

Mike

 

[Alan Gage]

As of now, my layup plan inside to out is 5 oz carbon, 3 oz plain Innegra, 7 oz basalt Innegra, 3 oz s glass.

Are you planning to put a foam insert in the floor? If not then from my limited experience I don't think you've got enough cloth.

I believe that, in terms of hull integrity, more important than the stiffness of the cloth is the thickness of the entire laminate. The stiffness of carbon won't make up for a thinner hull thickness.

It's been a few years since I really looked into this but I believe the ultra light manufactured canoes with a foam core were running 2-3 layers of 5-7 ounce cloth on the bottom of the hull. Without a core (solid laminate) it was more like 9 layers, obviously at a higher weight.

I've build a couple solid laminate canoes. If I remember right the solo had 9 layers of cloth (carbon, kevlar, and fiberglass) on the bottom of the canoe under the paddling station and the tandem had 10. The solo is isn't very rigid but it doesn't oil can and gives way nicely when hitting obstructions. The tandem oil cans easily when empty. Neither of them have terribly rounded bottoms so you could add stiffness by modifying the shape but even then I think your plan may be too optimistic.

There is a youtube video out there when Charlie Wilson was working for his old employer (don't remember which small manufacturer our East) and they were talking about their, pretty new at the time, vacuum bagging system. These were solid core hulls and Charlie said when they went to vacuum bagging they found they had to add an extra layer of cloth because their laminate was coming out thinner due to more compression and less resin. So the same number of layers and same type of cloth resulted in a hull that wasn't stiff enough because it was now a little thinner. It's hard to find a substitute for thickness.

Alan

 

[Mp214parks]

Hey Mike. I read your thread through a couple times. Great build.
As far as the order of lay up goes, I was under the impression that the stiffer fabric need to be on one of the outsides of the layup. So either the inside of the canoe or the outside of the canoe would qualify (based on my understanding). The basalt Innegra offers a lot more impact and abrasion than carbon. And it looks really cool. So I went with it on the outside. One downside to having the basalt Innegra on the outside is that you need to have a glass layer for sanding. But I can certainly be talked out of this for any good reason.
I think it was your build that convinced me not to use blue board foam and spend the money on dyvinicell.($200 for a 1/2”x4’x8’ sheet here) So my plan as of now is to rip the foam, angle it on the table saw, scarf the joints, and glue together ahead of time. Then day before hull layup, I’ll sleeve the foam , wet them out, and clamp them to the hull. I’ll take them off the next day, do the hull layup, then clamp them back on. This will probably make a release problem for me as it will stiffen things up a lot. I’m thinking maybe I can rip open the stern stem with a small skill saw to help if needed. My gunwale line is a little crazy with tumblehome at the paddleing stations and flare at the yoke. (It kind of looks like the savage river canoes.) so I want to make sure my gunwale line doesn’t distort on me. My gunwales will use 1” sleeve, so the are only 1/2” thick and about 3/4” deep. I’ll put separate inwales on when I do the interior trim.
The whole peel ply thing has got me confused. I think I’ve decided to use Duct window heat shrink for the mold covering/release. I’ve been with Composite Envisions. I called them and the stuff they recommended I use was $40 a yard, which is more expensive than any of my fabrics. I could see the benefit in using this on interior trim like ribs. But I don’t get the cost/reward on using it on the entire hull like I see being here.

 

[Mp214parks]

Alan, I gues that brings up the whole question of ribs vs. floor insert. I was hoping ribs would be sufficient due to the excessive cost of the foam. I was thinking of using 2” carbon sleeve around the 1/2” foam at whatever width fills out the sleeve. I’ve seen (in pictures only) Kevlar canoes done this way that had a total of 15 oz of Kevlar and 5 oz of glass. I’m not sure that the sleeves are the absolute best way to do it, but I like the idea of having a clean edge I don’t have to fuss with. I also might put in a couple bulwarks, one behind the bow seat and one in front of the stern seat area. This is to add to the seaworthiness of the boat. ( We will take on water during this race in high winds)
This canoe doesn’t need to be extremely ultra lite.
I guess another question is whether I should use S glass on the outside or if E glass is fine.

 

[Mrindy]

Cool idea on the gunwales! If I understand correctly, youre going for attaching the pre-cured composite outwales before removing the shell from the mold? That would save a lot of trouble dealing with a floppy hull later. You may not even need to stress about doing it immediately after the full layup and wait till both are fully cured (and trimmed) to attach them while its still on the mold, assuming your tumblehome cooperates. I think Alan did something like that one time, cant remember if he had to prefit the sleeved foam to the curve on the gunwale though.

Sorry if there is any confusion on the peel ply - the shrink wrap window plastic mold release is money. I was referencing using the peel ply on top of the completely wet out laminate. It helps avoid oversaturation, gives a clean finish, and pretty much negates any sanding. They must be trying to upsell you, the $3.50 per yard stuff works great: https://compositeenvisions.com/airtech-econostitch-peel-ply/

And I have some disappointing news...I need to add a foam core. It worked fine for tripping with packs, but empty it oil cans between the ribs with that flat racing style bottom. My first build was a Kevlar V-shaped hull and I was all Team Ribs. Now a reluctant defector. You could totally use that sheet you have though! Here are some sketches Im working on for cutting up a 32 x 48 foam they sell at express composites, for a visual. Hoping it works!

 

[stripperguy]

Your plug looks great!! I hope it will perform in the water as it does in your dreams...
As far as layup schedules go, the outer layers are needed for impact and abrasion resistance, inner layers for strength. When you hull has a load imparted (from the water or a beaver dam or rocks) the outside of the hull is in compression, the inside is in tension, and the intermediate layers will see shear. All of the high modulus materials perform best in tension.
Also, you'll gain far more stiffness from added section than you will from added layers. For a given beam (hull shape in your case) and layup schedule, the stiffness of the beam (hull) will be a function of the thickness cubed. There is no better way to increase stiffness and limit deflection than to add hull thickness. If you can do this with 5 lb/ft^3 Divinycell, you've got an ideal composite, lightweight and strong.

I would recommend leaving the stems open to allow you to pop the hull free around that tumblehome. Just don't wait too long, a day or so and the layup will still be pretty springy.You can easily finish the stems after the shell is off of the plug.
I also like the idea of those preshaped gunnels. Be aware that wrapping foam with carbon sleeve is sometimes a challenge. And many of the available carbon sleeving is incredibly thirsty, and may add way more weight than you anticipate. A couple layers of glass sleeve can provide the same stiffness, with less weight. But it won't look as cool...

Lastly, look at the cost of the 1/4" Divinycell and compare it to the cost of many multiple layers of carbon, kevlar, and innegra. I think you'll find that the foam is a bargain, especially if you consider cost vs strength vs ease of laminating. Your time is worth something, isn't it?

I'm looking forward to seeing your progress, you've got a great start so far. And a team of "experts" to help you out.

Mike T.

 

[NomadAK]

Great looking plug! I'll be following this closely. If you ever need an extra hand, I'm down in Anchorage and just starting my first build, and would love to lend a hand and learn a thing or two!

 

[Jim Dodd]

I'm not going to enter the lay up schedule, other than just to say, if you pull the hull off the forms, and find areas not stiff enough for your liking, add more layers where needed, on the Inside !

To start, lay up Full layers, over the mold, so you don't have fugly bumps to feather out later ! Do that on the Inside !

Very Interesting !

Jim

 

[Jim Dodd]

I guess another question is whether I should use S glass on the outside or if E glass is fine.

I know the cost difference seems a lot, but in your case, I think I would. I'd use S-glass Over the Innegra on the outside. It is sandable, but more durable for your use,

Was it Mrindy that just cloesed one end of his hull ? Some one did! Using the Duct heat shrink film, the hull will lift off like a feather ! Those that used PVA, struggled !

On My next, I will just leave one end open, and stay with the plastic as a release.

Jim

 

[Mp214parks]

Well you guys convinced me to do a foam core floor...

I have some 1/2”Divinycell, that’s what the local guys carry. But that seems like a little overkill. And the suppliers down south I’m seeing won’t ship to Alaska(FibreGlast). It seems like the 1/8” would be the only size that’s shippable since it rolls into a tube. Getting my local guys to get something special takes a month or more. Any comparable products out there? Or suppliers I’m not aware of? Or I guess using my 1/2” probably isn’t the end of the world, just a little extra foam. I could rip it and strip it from the inside. I just hate to throw away all the kerfs.

 

[BWCA66]

Not to throw a wrench in here but the Northwind description of their new canoe says that the basalt inegra is stiff enough to not need ribs or a foam insert. Wonder is vaccum bagging makes a big difference or if they have their own special inegra.

 

[Jim Dodd]

Not to throw a wrench in here but the Northwind description of their new canoe says that the basalt inegra is stiff enough to not need ribs or a foam insert. Wonder is vaccum bagging makes a big difference or if they have their own special inegra.

Many other manufacturers are getting away from the foam ! Yes ! I'd like to know their lay up schedule !

Jim

 

[Jim Dodd]

A pic, of how I handled getting the cloth to follow the Tumble home.

Again, I wetted just one side at a time, and tilted the strongback.