C-Forum

I've been wondering about laying up a composite open boat. I've worked with fiberglass making surfboards before, but all you do for that is wrap a foam mold in glass cloth. I was wondering what could be used for a mold, could you lay up a composite hull over an existing plastic hull without damaging the plastic boat using a release agent or something. If i were to make a completely new hull design, what can i use to make a mold? wire and clay maybe? Any info would be appreciated. I'm not trying to start anytime real soon, just a project for the future, that id like to start planning now. Any recomendations on the weight of cloth? preferences on epoxies and resins? Thanks in advance for your input

Any info on approximate amount of fabric in yards to make a single boat would be great too

Starting from scratch is a long, difficult process. Some free information is available at Fiberglast, and Charlie Walbridge's Boat Builder's Manual is still the Bible of Boat-making.

A rough estimate of material can be figured from your (theoretical) bare hull weight. The glass/Kevlar/whatever will usually constitute about 30% of the total with regular hand layup, 40-50% with vacuum bagging. Add 10-20% for scraps and trimming.

Don't do this unless you really want a new hull design. By the time you get done with the mold and the boat itself, you could have bought a better boat from Millbrook and skipped all the aggravation.

A friend of mine pulled a mold from a royalex boat a couple years ago and built a composite boat. You need to have a decent hull quality to do this, and then you make a fiberglass negative mold for both sides of the boat (split it down the center line). Then, you flip that right side up and lay your boat hull inside the negative mold and vacuum bag it.

If you check the BlackFly facebook page there are a few photos of the outside of Jeremy's mold, and a few photos of plugs. If you want to build your own boat, building up a plug can be done with anything, but I think dense foam with lots of bondo over the top is a common method. The Liquid Logic blog had some goood photos of this process from the creation of the Remix 100: http://shanesliquidlogic.blogspot.com/2 ... ody-i.html

If you have a design in mind, start with a stripper (wood strip boat, this IS a G rated forum after all ). You don't need to be as neat about it as you would if you wanted to make a wood boat - you'll be glassing it (and paddling it to test), adding bondo or other filler, gel-coating, and sanding (LOTS of sanding... likely at least a weeks worth full time), then you can pull a mold off your plug, THEN start making boats:)

It is a lot of fun, and very rewarding.

BUT, I'll echo the earlier comments - it will cost more than a brand new boat, even using cheaper resins and materials.

So if you want to build your own design and have the joy of paddling it, do it!

If you are trying to get another boat cheap, it won't be.

Having designed and built 4 boats now (2 flatwater, 2 C1 squirt) i can honestly say that wood strip construction is LESS time and material intensive than carving foam (Mentor) or cutting up and severely modifying another design (Maven... which in the end had no piece of the original boat left!).

Sweet Composites is a great resource, as are the Walbridge manual and Fiberglast.

I am by no means an exert on this but I'll give you what I know, or some of the most useful parts anyway.

First, making a composite boat from another existing boat without permission from the person/company that holds the rights is stealing and not a cool thing. It is possible to use a boat as a mold once it is coated with a releasing agent (the most common is similar to white school glue) but the resulting hull will be slightly larger or smaller depending on weather you lay it inside or outside.

Second, the amount of cloth that you will need will depend on the layup you do (how many layers), the size of the boat and the size of the cloth. For example, if you buy 60" wide cloth, which for most solo designs should be able to go gunwale to gunwale in the middle, then you can pretty much figure that you are going to need the length of the bottom of the boat measured from the bow to the stern times the number of layers you want in the layup. Keep in mind that this length will be LONGER than the boat length as there is the depth of the boat in the bow and the stern plus the boat length. Also, you will want a foot or so of excess so that you can have some wiggle room. SO, if we are doing a hypothetical layup of a 10' long canoe that is 16" deep, then you will need 120"+16"+16"+12"=164", convert to yards, 164"/36=4.55555556 yards of cloth per bout. I am not expert enough to recommend a layup schedule, some of that will depend on what you want and the design that you are building.

Third, making a mold can be done different ways. As has been mentioned you can carve foam to the shape that you want and then smooth it with clay or glass and finish with a release agent. Another way would be to build a wood strip canoe, either as a mold OR as a core for the composite layup. There are other ways but I don't know enough about them to be very helpful. As a note, I did all of the sanding on my wood strip canoe in about 12 hours with power random orbital sanders and a disk sander so it does not need to take that long. I built the whole wooden part of my canoe in 2 weeks of obsessive labor (I went to work, ate some and slept 3-4 hours a day, the rest was stripping) Also, if you decide to build a straight up wood stripper you do not need to be crazy careful with the wood construction, especially if you plan on painting it.

One other factor that you will need to consider is the amount of resin that you will need and the cost and weight of that. In an ideal layup with glass or kevlar, the cloth weight will be equal to the the weight of the resin. In a real life hand layup there is likely to be more resin than ideal and some of it will be wasted so plan on at least 20-25% more resin than cloth by weight (typical epoxy resin weighs approx 9lbs/gal).

If you decide to make a canoe, I recommend that you order more materials than you figure that you will need, if you have some left over you will have repair materials or the start of the next boat. One thing to note is that composite cloths do have a shelf life so don't order too much.

This is by no means everything that you will need but it will give you an idea to start with. If all you are wanting is a composite canoe then the suggestion that was given to just buy a Millbrook is a good one. Until you tool up, make a mold, buy composites and then wood for gunwales and such, you may have more in building one. If you want to be able to say that you made your own boat, want your own design or are looking a making several, then make sure that you know what you are getting into and have fun.

Building a canoe was a lot of fun for me and I will do it again but it is not cheap or quick. It is not that hard either if you have the time, patience and perseverance. Keep us posted.

Although what has been said here is all true...

....just by virtue of this question:

Any recomendations on the weight of cloth? preferences on epoxies and resins? Thanks in advance for your input

I wouldn't start the task before being able (through research and reading) to answer these questions for yourself. As these are really the most inconsequential of things you must know at this point.

Don't get me wrong it's a great project, and the only way to truly get what you want (or did want); however it really helps if this is a labor of love. As like said before, expect to invest more than 2-3 boats worth before getting the first production composite boat complete. There's the prototype cost, the mold coast, and the final boat cost. (Hint they all use different resin, cloth's, or fabric).

As your first step - my best suggestion is to first get your wood-stripper dialed in just right... carefully - paddle, paddle, paddle it some ... even maybe altering it 2-3 times (or starting over) before molding. Some people I've read - even go as far as saying it takes two molds to get one absolutely to plan... as the boat-or-part will (possibly, and likely) change some after popping from a mold. This especially true when gunwhaling a canoe, as opposed to a C1.

Sir Adam wrote:If you have a design in mind, start with a stripper

Are there any drawings available for a whitewater woodstrip canoe?

Normally I would say "none that I am aware of", however if you search the forum for the "stinkeye" as I recall tracings are available:)

I'm sure that Mikey B will chime in here but he did design and build the STINKEYE. I built one with help from Mikey and Millbrook is going to be making a composite version soon. I'm not sure if Mikey is still open to distributing plans as he didn't want to undermine sales for Kaz.

I did offer up the plans a while back, but nobody was interested. I told Millbrook that since they were wanting to build it that I wouldn't offer them out anymore. Funny all the interest in woodies now
Mike

And a "pirogue" (Craig I think that was your description of my baby ) got it started.
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Check with Kaz... since we're talking plans being shipped to Norway perhaps you can work something out.

I asked mostly out of curiosity. Here in Norway there are no whitewater canoes available on the market so one way of getting one is building it yourself. I do not have the time (but I have the tools) to build a canoe now. Hopefully I will have time in the future.

Barskekarsten,
I'd be more than to ship a couple crates full of canoes to Norway!

JKaz.