Composite Canoe Build

[Beast388]

Greetings! I am new to the forum, but I have been lurking for some time.

​I work for a company that produces both plastics and fiberglass products. In composites, we produce parts using the light RTM, vacuum bagging, chop, and wet layup processes. So, I have some experience with composites.

​In his company dealings, my boss acquired an old company that has been producing fiberglass parts since the 1960s. In the warehouse of this old factory, there was and old composite canoe mold that was in fairly good shape for its age. My best guess is the mold is 30-40 years old.

​Knowing that I like to canoe in the BWCA, my boss told me that I was welcome to refurbish the mold and build a canoe using leftover materials from the many R&D projects we have done over the years. I know....pretty sweet, right?

​I have a few rolls of 5oz Kevlar, as well as fiberglass in various weights and weaves. I am trying to decide what would be the best laminate schedule with the epoxy resin I plan to use. I have also been toying with infusing the gunwales at the same time as I infuse the hull.

​The mold will make a canoe that is about 18' long, with a 36" beam, and 12" height in the middle. It has three ribs in the bottom, with the center running from bow to stern acting as a keel. The stems are curved, hence the need to split the mold at the midpoint.

​My goal is to mold a canoe that will weigh less than 60lbs all trimmed out. I hope to take it to the BWCA this year with my 16 year old son.

​Does anyone recognize this design? My hunch is that this mold was created from a male plug, or a real canoe.

​This should be a fun little project!

​Here is the mold before the new orange surface coat. The original gelcoat was cracked and chipped.

IMG_2648 by bctc95, on Flickr

IMG_2649 by bctc95, on Flickr

IMG_2696 by bctc95, on Flickr

IMG_2697 by bctc95, on Flickr

IMG_2712 by bctc95, on Flickr


​And after the new orange gelcoat.....

IMG_2713 by bctc95, on Flickr

IMG_2714 by bctc95, on Flickr

IMG_2715 by bctc95, on Flickr

​Once I get the mold sanded and polished, it will be time to make a canoe.

 

[BWCA66]

Looks interesting, how does the mold work, the pics are pretty small to tell much. Laid up about 20 canoes the past 6 months using female molds and hand layups. Our layup in order is gel coat, fiberglass, Kevlar, carbon. All the fabrics are 5 to 6 oz.
Sounds like a fun project.

 

[Muskrat]

Standard layup for the home builder is from outside to inside: 6 oz s glass, 6 oz s glass, 5 oz Kevlar, 5 oz Kevlar. Most canoes have ribs or a foam core. With the mold you have, I would put extra material in those rib grooves. Those will take the most damage on the water and also provide the stiffness to keep the bottom from oil canning. It might even be worth filling them with foam afterwards and laying up a couple more layers of Kevlar on top. You'll probably need some extra fabric at least where the seats will go. I'd get a copy of Boatbuilders Manual by Charlie Walbridge. It's a dated book but very informative for layup schedules and stiffening systems that have been tried.

 

[Beast388]

Looks interesting, how does the mold work, the pics are pretty small to tell much. Laid up about 20 canoes the past 6 months using female molds and hand layups. Our layup in order is gel coat, fiberglass, Kevlar, carbon. All the fabrics are 5 to 6 oz.
Sounds like a fun project.

​With the mold splitting where it does, I will probably put tacky-tape (gummy tape) in between and then foil tape over the seam. Of course, with infusion there can be zero vacuum leaks.

​If you don't mind divulging, do you use just one layer of each in your layup? Do you put any additional cloth or core material in the bottom for stiffness?

​I plan to infuse some test plaques that are 12" X 12" to come up with the best schedule...and to come up with a weight per square foot, desired stiffness etc.

 

[memaquay]

Very interesting! Any way you can get rid of that tri-keel? The way you describe your layup, you won't need them. My understanding is that the good old tri-keels were added when using chopped spray type glass to enhance strength. You won't find them on many modern composite canoes.

 

[Muskrat]

Very interesting! Any way you can get rid of that tri-keel? The way you describe your layup, you won't need them. My understanding is that the good old tri-keels were added when using chopped spray type glass to enhance strength. You won't find them on many modern composite canoes.

Good thinking Mem, I'd be tempted to do the same. Those keels probably add quite a bit to the frictional resistance through the water.

 

[Beast388]

Very interesting! Any way you can get rid of that tri-keel? The way you describe your layup, you won't need them. My understanding is that the good old tri-keels were added when using chopped spray type glass to enhance strength. You won't find them on many modern composite canoes.

​While it is possible to put in the work to fill and sand to remove the tri-keel, I don't plan to do that. I am fine giving up a bit of efficiency to have the extra stiffness. I also like those being the low points in the water to take the majority of the abuse. I will be adding extra laminate in those areas for that purpose.

 

[BWCA66]

​With the mold splitting where it does, I will probably put tacky-tape (gummy tape) in between and then foil tape over the seam. Of course, with infusion there can be zero vacuum leaks.

​If you don't mind divulging, do you use just one layer of each in your layup? Do you put any additional cloth or core material in the bottom for stiffness?

​I plan to infuse some test plaques that are 12" X 12" to come up with the best schedule...and to come up with a weight per square foot, desired stiffness etc.

We use just one layer of each. We then put cherry veneer ribs on the inside to give it the classic rib and canvas look. There is a football shaped layer of chop strand under and on top of the ribs on the bottom. In addition to looks the veneer gives the stiffness needed. When we pull the hull out of the mold it weighs less than 30 lbs. Our canoes are all finished with all ash and cherry that almost doubled the weight. Website is merrimackcanoes.com

 

[Jim Dodd]

Very interesting! Any way you can get rid of that tri-keel? The way you describe your layup, you won't need them. My understanding is that the good old tri-keels were added when using chopped spray type glass to enhance strength. You won't find them on many modern composite canoes.

My thoughts exactly ! I'd fill in those keel ribs. They just add weight, and would be more of a pain to lay in extra cloth. and the release might be tougher ?
Most molds I've seen are mirror polished on the inside. Guessing to aid removal of the hull ?
I have seen fiberglass hulls that appeared to have been made with a chop gun, and that had a molded gunnel, but I can't put a name on it.

Welcome Beast388 ! Very interesting thread ! Please continue to update !!
Your not here in Iowa are you ?

Jim

 

[Beast388]

Most molds I've seen are mirror polished on the inside. Guessing to aid removal of the hull ?

​After spraying, the gelcoat typically has an orange-peel finish. It will be sanded starting with 220 grit and ending with 1500 grit before being polished. Any imperfection in the mold will visible in the finished product, which in this case is a canoe.

I have seen fiberglass hulls that appeared to have been made with a chop gun, and that had a molded gunnel, but I can't put a name on it.

​One interesting thing about this mold is the scallop where the gunwales will go. My initial thought was to trim the hull after infusion where it meets that scallop, but I want to use that detail as part of the infused gunwale if I can figure out how to do it.

Welcome Beast388 ! Very interesting thread ! Please continue to update !!
Your not here in Iowa are you ?

Jim

​Thanks for the welcome. Yep, here in Iowa....way on the east coast. What was the clue?

 

[Jim Dodd]

Awesome ! The snow was the first real clue, and then the River Maples, in the back ground.
I may know where a canoe, here in town, that is at least similar. I'll check this Spring sometime.

The way the mold is widened at the shear, something, maybe a wood core could be wrapped, and infused ???

I'll PM you !

Jim

 

[Beast388]

The way the mold is widened at the shear, something, maybe a wood core could be wrapped, and infused ???

​That is my line of thinking right now. Using a proper foam would be easier to shape and work. But, I would be worried that a wrapped, infused foam gunwale would be too weak for the load that seats, thwarts and the yoke would inflict on it. Maybe if the foam was wrapped with two layers of 5oz Kevlar would be up to snuff? Decisions, decisions.....

 

[Jim Dodd]

Thinking the Kevlar would definitely add strength, carbon fiber would add stiffness.

Yes, foam would be easier to conform to the mold shear ! Maybe thin strips of wood laminated, to the shape of the shear, before hand. Then when you laid in the hull glass, the wood gunnels would just sit in place ??? Just food for thought !

I'd be tempted to glue in cleats for the seats, instead of stressing the gunnels.

Decisions !!

Jim

 

[Beast388]

​This video has been posted on this forum already, but I find it interesting at the 3:22 mark it appears that this craftsman is using a profile made from cork? The profile is then wrapped in fiber and peel-ply and infused with the hull. He then drills through the gunwale to make his attachments. Hmm...

 

[Jim Dodd]

I've seen this video a few times. I wonder what the brown cloth was? It stated a natural fiber. Jute maybe?

Jim

 

[Beast388]

I've seen this video a few times. I wonder what the brown cloth was? It stated a natural fiber. Jute maybe?

Jim

​Looks like it might be flax....

 

[Jim Dodd]

Yes ! Next , and I'm guessing you knew this was coming ! Is it available, here in the States ?
Maybe Fabric shops, carry Flax cloth ? Time for a Google search !

Thanks Beast !

Jim

 

[Muskrat]

Swift used flax cloth a few years ago. Not sure if they do still. If you're looking for flax at fabric shops, it's called linen. For a composite though anything you could find at a fabric store would probably be too tight a weave.

 

[Jim Dodd]

Thanks Muskrat !
The wife says we're shopping tomorrow ! So I'll have a chance to look at least locally !

Jim

 

[Beast388]

After 4.5 hours sanding the orange peel surface smooth....I looked like a Dorito....

IMG_2730 by bctc95, on Flickr

​I still have the other half to do...then work my way up through 400 grit....and then I will probably buff at that point. I've got to remember that this isn't a production mold....and a glossy mirror finish is not needed.

​Making progress....