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Canoe building question

tx river rat

Well-Known Member
Feb 23, 2007
3,043
2
Waco Tx
Oh I am not knocking carbon , but the fiberglass will build a boat with out all the bagging and expense.
Unless I am misunderstanding something ,using foam or another boat for a plug is a pretty complicated deal . When we did that in the power boat business we figured several thousand hours to make a plug then,pop a hull off that is braced for a mold sand and wax the inside and then you are ready to lay up your first boat.
Fiberglas boats being one layer have to be built up much heavier than a composite boat in a normal layup., just look at the advertised weight of fiberglass yaks.
Ron
 

JEM

Well-Known Member
tx river rat said:
Oh I am not knocking carbon , but the fiberglass will build a boat with out all the bagging and expense.
Unless I am misunderstanding something ,using foam or another boat for a plug is a pretty complicated deal . When we did that in the power boat business we figured several thousand hours to make a plug then,pop a hull off that is braced for a mold sand and wax the inside and then you are ready to lay up your first boat.
Fiberglas boats being one layer have to be built up much heavier than a composite boat in a normal layup., just look at the advertised weight of fiberglass yaks.
Ron
Ron - "Building Your Own Kevlar Canoe" is a good read. Doing a fiberglass production is using a "female" mold. The one in the book, you're building from a "male" mold from foam, coating it with wax, and then popping a hull of it. So the time of building a male foam mold and popping a hull off of it is about the same as building a foam cored hull that you would have to glass inside and out. The one in the book then does use some lateral foam stiffeners with fiberglass covering.

Now if you're creating a female mold, then you have to build the male plug, then pop the mold, polish, etc, etc. Takes a lot longer but you're hull count from it will be in the 100s. With the male foam plug, you'll get 2, maybe 3.

A note on carbon fiber: You don't have to bag it. It'll wet out. Kevlar is a bugger because it tends to "float" in the resin instead of soaking it up. But it can be done. Kruger canoes are all hand-laid kevlar.
 

project

Member
Jun 1, 2011
15
0
tx river rat said:
Oh I am not knocking carbon , but the fiberglass will build a boat with out all the bagging and expense.
Ron
You dont have to bag carbon.. you can lay it up just like glass. All the vacuum bag process does is remove extra resin and air from the layup which results in a stronger and lighter part.. Fiberglass can be bagged the exact same way and will be lighter as well. The bagging isnt as expensive as you might think, could probably get set up for $300 or so, not that it would be much use on canoe building but would help in building some light and almost bullet proof paddles.
 

swampwood

Well-Known Member
Aug 6, 2010
274
2
Bayou State - Louisiana
JEM said:
tx river rat said:
Oh I am not knocking carbon , but the fiberglass will build a boat with out all the bagging and expense.
Unless I am misunderstanding something ,using foam or another boat for a plug is a pretty complicated deal . When we did that in the power boat business we figured several thousand hours to make a plug then,pop a hull off that is braced for a mold sand and wax the inside and then you are ready to lay up your first boat.
Fiberglas boats being one layer have to be built up much heavier than a composite boat in a normal layup., just look at the advertised weight of fiberglass yaks.
Ron
Ron - "Building Your Own Kevlar Canoe" is a good read. Doing a fiberglass production is using a "female" mold. The one in the book, you're building from a "male" mold from foam, coating it with wax, and then popping a hull of it. So the time of building a male foam mold and popping a hull off of it is about the same as building a foam cored hull that you would have to glass inside and out. The one in the book then does use some lateral foam stiffeners with fiberglass covering. Now if you're creating a female mold, then you have to build the male plug, then pop the mold, polish, etc, etc. Takes a lot longer but you're hull count from it will be in the 100s. With the male foam plug, you'll get 2, maybe 3.

A note on carbon fiber: You don't have to bag it. It'll wet out. Kevlar is a bugger because it tends to "float" in the resin instead of soaking it up. But it can be done. Kruger canoes are all hand-laid kevlar.
I built 2 canoes using the very same book.
They were both built using Kevlar and I used 3/4" styrofoam as a mold for the ribs and fiberglassed over them.
They were very strong and could take a heck of a load.
 

tx river rat

Well-Known Member
Feb 23, 2007
3,043
2
Waco Tx
Addressing some of these post , 300 dollars for a bagging set up , I can build two boats for that or close to it.
Kevlar is not an option here . here is the general thought about boats built from it
Quote
Kevlar: light weight, strong, not very durable on rocks or hard surfaces, expensive.

That sure doesn't suite my kind of paddling. So I dont even consider it as a material that would meet my needs.
Molds
Laying a boat up on the outside of a foam mockup is sure doable, Like Mat says for one or two boats. To me this is basically a strong back, your hull is going to be rough on the outside
smooth on the inside, the dimensions are going to be larger than your model and kevlar is a bugger to sand and get smooth. To me a mold is something that give a finished product that has the same dimensions as the original, Just the way I think of the word mold.
Swamp thats neat do you have any pics ,would love to see them.
This conversation has gone way off the subject it was started for but I have learned a lot so I guess it is a good thing. I do appreciate your information and resources you have posted.
Thanks
Ron
 

swampwood

Well-Known Member
Aug 6, 2010
274
2
Bayou State - Louisiana
Ron,
No pics.
You are right about the smooth side on the inside, but you also build the epoxy up on the outside and sand it smooth. The same as you fill the weave on fiberglass cloth.
The kevlar is tuff and am sure it would withstand more abuse than an wood fiberglass boat.
 

tx river rat

Well-Known Member
Feb 23, 2007
3,043
2
Waco Tx
Yep your right Seedtick but I am not going to vacuum bag a boat.
Swamp the little Kevlar I have fooled with doesnt sand worth a flip it fusses.
and I have to disagree with you on a wood boat with fiberglass , I have run enough races where they used them and watched them on the bank putting duck tape over holes, havent had to do that on one of my wood boats yet Kevlar is strong but brittle.
Ron
 

swampwood

Well-Known Member
Aug 6, 2010
274
2
Bayou State - Louisiana
swampwood said:
Ron,
No pics.
You are right about the smooth side on the inside, but you also build the epoxy up on the outside and sand it smooth. The same as you fill the weave on fiberglass cloth. The kevlar is tuff and am sure it would withstand more abuse than an wood fiberglass boat.
Ron,
you do not sand the kevlar cloth. Just like you should not sand the fiberglass cloth. You should only be sanding (epoxy).
 

JEM

Well-Known Member
Kevlar will "fuzz" if you have to sand it for a repair. It's a pain. I've seen some shops use a razor blade to cut a "squared edge" to avoid fuzzing. Heard some use sand blasting. :shock:

But I thought the "standard" method for using it in hull lay up was sandwiching between e-glass or s-glass. No?
 

JEM

Well-Known Member
CanoeCritter said:
I was wondering if anyone has tried to build a wooden strip canoe using a foam core instead of the wood strips. The foam I am considering is the type used in construction.

Would it retain enough strength?
Would the epoxy properly adhere to the foam?
And any other questions I should be asking.

CanoeCritter
Back to the oringinal question: Hey you could get really silly:

They make braided carbon fiber and s-glass sleeves (like a sock). Great for push poles and paddles. You could make the hull from 1" wide foam strips, then sleeve each strip in carbon fiber. Then the type of foam wouldn't matter. :mrgreen:

Oh yea your boat will probably cost about $8000. :lol:

Hey wait a minute... what it you actaully did that to every 5 strip or so to form like a skeleton? Could use a wood strip.
 

tx river rat

Well-Known Member
Feb 23, 2007
3,043
2
Waco Tx
Swamp
It is sort of funny what I am playing with really has nothing to do with Kevlar , vacuum bagging building a mold.
I like to play with different styles and try new things ,so I am playing with a new ideals with the foam building. If I work it out it should be an extremely light tough cheap boat , if not I will have a lot of foam for corks and bobbers for fishing. :lol: :lol: :lol:
which ever way it goes I will be the winner just from the experience and knowledge I gain.
Like your tag says some are builder and some are craftsman ,I know where I fit , I am a builder and love trying something new .
Ron
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,553
97
82
Okemos / East Lansing Michigan
tx river rat said:
<SNIP> Contrary to what jack stated you are not just using the outside skin, with the dowels you a have a rigid impact resistant unit where the load is spread completely thru it. <SNIP>
Somewhere, maybe a computer cable got a half twist in itself? :roll: What I'm saying here restates that the strength does NOT come from the outer skin alone. It is a combination of outer (skin) and inner (core) strength together. We agree, Ron.
Kayak Jack said:
<SNIP> Trying to use the outer skin as the sole, or primary, source of strength is in between very difficult and beyond a point of diminishing returns. <SNIP>
 

CanoeCritter

Member
Jul 5, 2011
5
0
Well I definitely got a lot of good feed back and really good information.
I'm with Ron, Kevlar is out, vacuum bags are out. I want to build a nice light weight solo canoe as inexpensively as possible.
Most of the water I run in are rivers with some bumping and rubbing, nothing too severe. But, I do want to build a canoe that will last for quite a few years, not just a couple.

This really has me thinking.....

Should I? or shouldn't I? That is the question. :D
 

Kayak Jack

Well-Known Member
Aug 26, 2003
13,553
97
82
Okemos / East Lansing Michigan
CanoeCritter said:
<SNIP> Most of the water I run in are rivers with some bumping and rubbing, nothing too severe. But, I do want to build a canoe that will last for quite a few years, not just a couple. <SNIP>
A consideration about rocks is - what kind are they? Sandstone that has been worn round in a river isn't as rough on a boat as is, say, freshly broken (last 25-50 years) igneous rocks. Quartz, gneiss, granite, etc. come with lots of sharp edges and points to concentrate their inflicted damage to a very small - but deep - area. Your boat's outer skin may or may not be suited to the rocks where you paddle?
 

JEM

Well-Known Member
CanoeCritter said:
Well I definitely got a lot of good feed back and really good information.
I'm with Ron, Kevlar is out, vacuum bags are out. I want to build a nice light weight solo canoe as inexpensively as possible.
Most of the water I run in are rivers with some bumping and rubbing, nothing too severe. But, I do want to build a canoe that will last for quite a few years, not just a couple.

This really has me thinking.....

Should I? or shouldn't I? That is the question. :D
Of course you should!! :mrgreen: