Canoe Definitions

tumble home on a a canoe
Tumble Home on a canoe looks like this

Definitions of Canoe Terms

Gel coat – silica sand in a vinylester or polyester resin base which is applied to the canoe to reduce abrasion in kevlar or fiberglass canoes.  Adds weight and sometimes cracks up on impacts.  Gel coat is on everything from canoes, to speed boats, to shower stalls.  Makes a nice clean, smooth finish but also hides serious flaws and sloppy workmanship.  Avoid canoes which have gel coat on the inside – too heavy and who knows what your getting?

Royalex –  (extinct)  Trade name for an ABS plastic foam sandwich material which in the canoe world, has a vinyl color on the outside, a thin layer of harder ABS plastic next ( whitish-green color), ABS closed-cell foam next (grey, foamy looking) ABS plastic layer (whitish-green again) and the inside layer of vynil color.  It comes in big sheets, is heated in a oven and then sucked into a vacuum mold the shape of a canoe that comes down from the ceiling to pick it up.  It cools rapidly in the mold which splits open and drops the newly formed canoe to the floor where it is trimmed and gunwales and seats installed.

Polyethylene (P-tex) – available in linear or crosslinked design.  Linear is just one sheet of tough polyethylene which has been formed to make a canoe using heat.  Incredibly tough, but makes a cheap, bathtub-like canoe which usually needs the support of a keelson (long pipe or tube that lays in the keel in the bottom of a cheap canoe) and other aluminum tubing to keep its bottom from flopping up and down in the water.  Cross linked polyethylene canoes are usually formed from poly pellets in a heated, rotary mold which spins and rocks as the first layer (outside layer) is dumped into the mold and melted into a canoe.  Then the middle foam layer is added and finally the inside layer of pellets is added. Whole thing then cools and out pops the craft.  These are heavy and indestructible canoes and about the same price as lighter weight aluminum canoes.

Cloth Layup Canoes – canoes which are made from essentially some sort of cloth that comes off of a big roll.  Layers of cloth is cut into a rough shape, laid into a female mold and resin is pour in on top of the cloth and then squeegeed  thru the layers using paint rollers and rubber squeegees. These canoes are made out of various blends of cloth including but not limited to kevlar, carbon fiber, fiberglass, duralite and tuffweave  (both proprietary cloths made by different companies as a less expensive alternative to more expensive exotic cloths like kevlar, et al.)

four sheet construction
This is what four sheets of cloth would look like. They are laid into a female mold and wetted through with resin. The resin hardens, the mold comes off, and the result is a cloth-layup canoe. Could be kevlar, fiberglass, polyester, or old T-shirts. The cloth gives the shape and reinforcement, the resin seals out the water.

 

Vinylester resin – a two-part resin used to hold cloth layup canoes together in the shape of a canoe.  Generally thinned out with liquid styrene to make if flow more easily at room temperature.  Cures at room temp.  Bonds to fibers at about 500 PSI .

Epoxy Resin – a two part resin that holds cloth into shape of canoe.  Applied under heated conditions and requires heat to cure it in its purest form.  Bonds to fibers at 2000+ PSI

Skid plates – A “shoe” or covering made from kevlar felt material.   It’s a thicker cloth that acts more or less as a sponge to hold a larger quantity of resin in one place for the canoe to use as guard in the bow and stern areas which take the greatest abuse on any canoe.  Skid Plates or Bang Plates save the bow and stern from abrasions received while landing the canoe or pushing off from shore.  The bow and stern take the most abuse since the entire weight of the canoe ends up on a little strip about 1/2″ wide by 4″ long if you slam into shore.  The bows of  kevlar and plastic canoes without a good skid plate don’t last long in these situations so you see a lot of “wet foot” canoeing where paddlers jump in up to their knees to save that delicate bow or they install the skid plate themselves.  A few companies build them right into their canoes.  On other canoes, it’s up to the canoe owner to install or have them installed if needed.

Skin-Coat hulls – are made of,  in most cases, just the resin that’s been squeegeed thru the cloth layup of the canoe when it was built. The shine you see on a skin coat is resin which cured making a duplicate of the female canoe mold.  Many major companies make skin coat canoes because they are the lightest in weight.  Unfortunately, the resin doesn’t provide a lot of abrasion resistance and rocks literally can tear into the bulky/coarse weave of kevlar cloth as the canoe passes over them.  When you flip over most used,  skin coat kevlar canoes and examine them closely, you’ll see that there are fibers about 1 mm long sticking out along the scratch.  To prevent fiber tear-out in kevlar canoes, some builders apply a thin layer of fiberglass over the kevlar.  Fiberglass is easier to repair, holds up to abrasion much better and ultimately protects the main cloth (kevlar, carbon, etc.) from excessive damage.

Flat Canoe Bottom
Flat Canoe Bottom – Feels secure, but can tip suddenly when canoe is leaned to far.

 

Shallow-arched bottom of canoe

Shallow-arched bottom of canoe- feels tippy and jittery but can lean over much farther than flat-bottom without rolling over completely.

 

cantilevered canoe bottom
Cantilevered canoe bottom – unsettling feeling when canoe is not fully loaded.  It feels tippy with a light load and will either “dump” to the right or left and then stabilize.  More suited to white water for leaning the canoe over to maneuver quickly.

The best canoe bottom is a combination of flat and shallow-arched shapes.  Then it has good initial stability and the ability to lean over without rolling (secondary stability).

rocker
Canoes with “rocker” can turn and maneuver. Non-rockered canoes don’t turn easily and travel faster through the water because they are not pushing that upside-down “hump” you see in the exaggerated diagram.

 

tumble home on a a canoe
Tumble Home on a canoe looks like this – the top sides of the canoe hull in to allow for more comfortable passing by of your hand on the lower part of the paddle.

I don’t care what anybody says.  Tumblehome does absolutely nothing for the canoe’s stability.  It exists to allow your bottom hand clearance when holding the paddle.   Also, tumblehome promotes sloppy paddling technique as you are able to keep the paddle in a “sweep” stroke position as opposed to as perpendicular to the water as possible.

So there you have it.   More information than you probably need, but it’s free.

 

 

 

 

 

 

 

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