Composite Canoes Glossary of Terms & Frequently asked Questions:

What is gelcoat?
The first step when building a composite boat is to gel the mold. Gelcoat provides a smooth glossy exterior & colour choice. Gelcoat covers the fibreglass / Kevlar or carbon cloth to provide an exterior layer of durability & impact resistance. The main purpose of gelcoat is its slippery surface better enables a boat to be relived from the mold upon its completion

What is a hand Lay-up?:
Means excess resin is removed by hand without the help of an automated pressure process like vacuum bagging or infusion

What is vacuum bagging?
Originally an aerospace technology, vacuum bagging is similar to a wet hand lay-up, except a bag is put round the boat & mold. The air is then retracted from the bag. This presses the material mix together, which in turn pushes excess resin out. This pressure process maximizes a boats cloth to resin ratio, which in turn builds a stronger, lighter boat. Remember resin is simply a binder, thus excess resin provides little positive function except to add weight

What is Infusion?
Infusion is similar to vacuum bagging except the boat is layed-up ‘dry’ – meaning without resin. A hose runs from a resin container up in throughout the hull of the mold. The air is then retracted from the bag until zero gravity is achieved, which then enables the resin wick up into the boats cloth ~ like water creeps into a paper towel. Infusions manufacturing advantage is that there’s less labour required!

Can you explain the different types of resins?

Sure, resin is “the glue” which holds all the boats building materials together. Put simply, “da better the resin da better da boat”! There are 3- main types of resins used today:

- Polyester Resin:
The least expensive resin. Its offers less flex than other resins and is normally used in standard fibreglass boat construction

- Vinylester Resin:
Vinylester resin offers a good compromise of price vs. strength characteristics. Premium weight fibreglass, moderate weight Kevlar and even some ultralight Kevlar boats are made using vinylester or blend of vinylester & epoxy resins. Vinylester & epoxy resins flex better than polyester resins

- Epoxy Resin:

The most expensive & strongest of the 3- resins, 100% epoxy resin is normally used to build ultralight boats. Difficult to work with epoxy often cures best in a heated mold.
Note: 100% epoxy boats will still have a thin vinylester skin as it weathers better than epoxy on exterior surfaces

Can you explain the Pro’s & Con’s of Hull Cores vs. Flex Ribs?
You bet, consumers can choose either

- Rib or Flex Ribs:
Ribs are used as hull stiffeners and to minimize weight. This technique provides moderate flex between ribs and non-flex points underneath the ribs. This process actually maximizes a canoes rip n’ tear points or flex vs. non-flex points as the hull travels over an object – like an underwater object

- Core Bottoms:
A diamond shaped dense foam core is pulled to the boats hull using a wet vacuum bagging or dry infusion pressure process, while also sucking excess resin out. Unlike ribs, a hull core material EQUALLY disperses stress throughout the entire length of the boat – an obvious advantage over older rib technology

What factors can alter a boats weight from the manufacturers listed weight?

- The Boat Building Process:

People make hand-layed boats and last time I checked people aren’t perfect, thus weights can vary up to 5 lbs. Vacuum bag or infusion boats material amounts are precisely controlled by the automated process, thus weights seldom fluctuate more than a pound or two

- Gelcoat Colour Choice:

Bright colours vividness is largely achieved by adding more gelcoat, thus darker colours tend to weigh more than lighter colours… yellow is the heaviest!

- Wood Trim:
Wood trim gunnels can add substantial weight to a canoe (ash: 5 lbs, Cherry 3 to 4 lbs). Also remember wood can fluctuate greatly. Anybody who ever bought a bunch of 2 by fours knows you get can vastly different weights

- Manufactures:

A manufacturer can make an honest mistake, however sometimes they might specify a lower weight for a perceived sales advantage

We trust our Frontenac Outfitters article has helped you better understand Canoe Materials & Modern Manufacturing Processes

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