Builders' Forum Archives
Re: kevlar LT17
Posted by LeeG on Oct 26, 2005
Howard hit all the important points, put a tough material at the high wear spots. Thereafter if you want something more durable than 6oz e-glass glass because you're regularly landing on rocks,are a heavy person, or expect to side surf onto rocks with a loaded kayak consider simply add another layer of 4oz glass on the "football" area which is the bottom of the hull about 3' behind the aft bulkhead to 2' forward of the front bulkhead in a diamond shape. If you have money to burn and really want to go to extremes then it's worth reconsidering the regular glassing schedule and utilize s-glass on the exterior as it's more abrasion resistant than regular e-glass, easier to work with than kevlar and as repairable as regular e-glass. The reason for reconsidering the existing glassing schedule is that anything that will be impacting 6oz e-glass over 4mm okoume to failure will require interior reinforcement to balance. To have significant improvements over 6oz e-glass you won't find it with 5oz kevlarcloth. Kevlar felt may work well for canoe skid plates and cloth for composite kayaks but for the exterior layer of a structural material like 4mm okoume you want something that will prevent impacts from dinging (allowing impacts to compress the wood). Kevlar is strong on tension but not on compression. That means that although it's a bear to tear it won't prevent impacts from compressing the wood as well as a material that is high in compression,,which is glass. Also 5oz kevlar will require MORE epoxy than 6 oz e or s glass. So you could put on a regular exterior layer of 6oz e-glass and another 4oz on the bottom and it'll only cost another $15 or so and I bet it'll weigh less than a total layer of 5oz kevlar while providing better impact resistance on the bottom.
In Response to: kevlar LT17 by Pat Egan on Oct 26, 2005