Dear Brian,

Don't use Kevlar on the outside of your kayak hull. Even in kevlar commercially made kayaks the outer layer or three are almost invariably made with some typre of fiberglass cloth with the kevlar being left for the innermost layers. This is for several reasons:

Although Kevlar has a tensile strength greater than that of steel, its compression strength in a FRP laminant is actually less than standard e-glass. This means that the outermost layer of your boat--which is in compression when striking an object--should be standard fiberglass. In addition, kevlar is opaque, hard to wet out with resin, expensive, and difficult to work with, as well as being really expensive. Kevlar does not abrade smoothly, and it is subject to UV degradation. Only when the kevlar is used on the inside of the hull, it is performing its best role in preventing a catasrophic puncture due to its high tensile strength. To protect your boat against grounding damage I would suggest thefollowing alternatives to layering your boat with really expensive kevlar:

Add an extra layer of fiberglass tape or cloth to the high wear areas on the keel line, bow, stern, and seating area.

Glue on a new layer of protection in the areas that need it every fifth year or as necessary.

Don't land on the oyster shells if you can help it.

Good luck with your new boat!

--James McMullen