I am considering building a canoe using the "Building Your Kevlar Canoe" by James Moran, however I am thinking that I might use a Kevlar/Carbon fiber weave cloth instead of just Kevlar.

Sorry to say I have zero experience with any layups, however, I am willing to give it a try. Can you think of any disadvantage of using hybrid fabric? There of course will be a cost difference. The design does call for use of s-glass over the Kevlar.

Has any one built a canoe using his method?

What do you think of the use of the hybrid fabric?

Hybrids give you the benefits of both. You need less material to gain structural strength so you can save some weight. With carbon/kevlar you get a strong laminate and it wears well.

....... ain't cheap tho....

Still a good idea to use an e or s glass along with it so you can keep the fabric weight of the C/K down (helps with cost a bit too).

Using epoxy or vinylester resin would work better with the hybrids, seems to saturate the fabric better than some polyesters available. They are both a little more felxible than most poly's too so less likely to fracture in a lighter more flexible laminate.



Cheers,

Thank you for the reply
Mr Moran book calls for use of S-glass over the Kevlar. He also states not to use polyesters. I guess you agree with him.

I've noticed the Moran book has been mentioned by a couple of other folks on this forum, I'll have to source a copy and give it a look.

I was really curious what he used as a form or mould.

The book was published in 1995 thus some things have changed (like carbon fiber fabrics becoming more popular).

The basic steps are as follows:
Use one of the three plans the author offers, modify one, or design your own
Transfer the plans to plywood and cut out.
Attach the stations (plywood) to the strong back.
Cover the form with ripped sheets of construction foam
Cover the construction foam with drywall compound and shape as desired.
Apply paraffin wax to the mold
Apply mold release wax to the mold
Fit the Kevlar on the mold and epoxy
Fit the s-glass over the Kevlar and epoxy
Remove the 'canoe' from the mold
Seal the bow
Attach the gunwale
Add reinforcing ribs
Add seats
Have fun.

I obviously skipped the finer detail.

I have this book. The hybrid fabrics are nice but you still need something to protect Aramid (Kevlar). Amamid is great stuff but gets fuzzy when it's scratched and will start to wick in water. If it does get scratched, repair it is a messy process and it's hard to make it look nice. You basically have to bury the frayed fibers.

S-glass has nice propeties of its own in addition to great abbrassion resistence and ease of repair.

Epoxy has better strength properties and is easier to work with than poly, as you may already know. Poly just stinks to high-heaven and is not forgiving to mixture errors like epoxy.

I've wanted to give this a try but haven't taken the leap yet. One concern I had is using the drywall (sheetrock) compound. It'll break out easy and an example of that is even shown in the book. I guess for a one-time use, it would be good enough. I keep debating that what if I like it and want to build another? I'll have to repair the form. But I suppose it couldn't be too hard.

Wishy-washy, I know.

Might be an idea to play with glassing a bit on another project with lower cost materials before putting it to the test with 1000$ worth of High tech materials.

Kevlar and carbon and even S glass are all more dificult to work with than the normal E glass.

I too have Morans book , though I didn't care for his designs the technique for building a mould are unique. One way to make a sturdier form is to use drymix drywall compound. The kind that sets up in 20-30-45 or 90 minutes. One brand name is "Durabond".

This compound sets up harder than regular DW compound, almost like plaster, and would make a stronger surface for waxing and laying up a canoe.

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Solo canoes and single blades, with a sail for those windy days...

...........O
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It's basically a "one off" male mold so you could also use any design available as a strip build boat (Bear Mtn, Green Valley, Guillemot, etc).

If drywall compound doesn't suit your needs a light-weight automotive body filler would work as well but smell more obviously. The light-weights sand out quite well.

Good old floor paste wax can sub for parrafin.

The only real trick to carbon, kevlar or S glass is taking extra care to saturate the fabric well, it doesn't absord the resin as readily as e glass. You can use a squeegie to work it into the weave well then flatten it out and get rid of excess resin. A final flood coat over the weave to make sure it isn't exposed. It's the same process as glassing a stripper (boat that is... )

If you are going to use expensive hybrid material "CanoeCraft" has some excellent advice on glassing with epoxy. Might be a worth while investment or there's tons of free advice on forum's like this one.......



You don't have the noxious fumes with epoxy but you still need good ventilation and protection for skin. I've found proper mixing to be more critical and unforgiving with epoxy.

I would think using epoxy might be the better choice of the resins, it's more flexible and less prone to fracture but it isn't UV stable so needs protection. Varnish for a clear finish or paint and cover up all that expensive hybrid fabric....
Poly or vinylester's should get some protection as well.

Sounds like it would be a neat project for a home builder. If you decide to jump in keep us posted on progress.


Cheers,

yes definately worth mentioning....while epoxy doesn't stink as bad as poly, good ventilation with fresh air supply...not just blowiing the air around, is important.

If indoors, a small box-style fan blowing out one window with another window or door open to draw air in from is a good idea.

Some thoughts.

First, you might consider building a stripper first. Once you have the outside layer of glass on you can then wax up the stripper and build your laminated boat over it. Once you laminate your boat take it offf, pull the stripper off the forms and glass the inside. I always use Partall #2 wax with a good healthy coat of PVA release agent. to guarantee release. (All available from most fiberglass supply stores)

Now you have two boats. Sell one to pay for the other.

The difference between the stripper's performance and laminated boat will be so minor that you would never notice it.

I have done this and it works. Sort of a "waste not want not philosophy".

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Cheers,

John Winters

....... if you do opt for the "stripper as plug/ 2 boats at once" option look into the newer tripping designs rather than something with recurve and tumblehome.

Bit of a fix if you end up with a boat and plug you can't get apart

You would have a unique canoe tho.............



Cheers,

Komatiq,



IIRC, making the kevlar hull includes opening up both ends along the midline where the stems would normally be... so even with recurve and tumblehome, opening and detaching the kevlar beginning with the stem areas should allow for enough separation so that the kevlar version can be lifted off the cedarstrip. There's an option for versatility here, since one version can be built for looks (the cedarstrip) and the other for greater durability, with more reinforcement. Or vice versa, with the kevlar being the ultralight version.

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><((((º>

Thanks FT, I'll be sure and mention that I was joking in future posts rather than rely on using just 's



..... figured Deleteriousone would know what I meant.

Sorry for any confusion folks..........

Cheers,

[quote="Komatiq"] . . . Bit of a fix if you end up with a boat and plug you can't get apart
I did understand this statement was in jest; however, there is a kernel of truth in it. I have read some accounts of people needing to destroy the mold in order to release the Kevlar shell.

I would love to have a cedar strip canoe as well but in this case it will not work for several reasons.
1) I will not have the finances to build both (even if I were able to sell one)
2) The reason for the Kevlar / Carbon version is so I can port the thing alone.
3) I do not have the tools necessary (I will need to borrow many of the tools just to make the Kevlar version)
4) Most importantly, I do not have by any stretch the needed skill set to accomplish that type of woodwork (at least not and make a boat that floats )

I do have a few other details which the fine folks of this forum may help.

The plans call for 8.9oz Kevlar, however I can only find 5.5oz in the hybrid cloth.
Would the stiffness of the carbon fiber in the hybrid cloth be enough to compensate for lower weight?

What is Texalium aka "Silver Carbon Fiber"? Is it carbon fiber? How does it compare to carbon fiber / Kevlar?