Laser 28 construction materials

George,

The early boats were all made of kevlar but somewhere along the way a change to fiberglass was made. I don't know at what point this was done, perhaps Bill Layton from this board will chime in with a better answer.

The actual reason it was changed was because of difficulty in 'wetting out' the kevlar properly in the lamination process. It was found the boat could be made equally strong with fiberglass and be easier to make, only it was no longer 'bullet proof'.

The long term experience with these boats shows that there is really no reason to prefer either one over the other from either a performance or longevity perspective.

Hope this helps a bit George.

Cheers,

Hi George,

Our supplier of Kevlar at the time was Dupont. In early 1986 the cost of this material doubled overnight... needless to say as a manufacturer we simply couldn't afford such major increases.

We consulted with Bruce Farr and he suggested a new weave of Glass called "S glass". It was recently new to builders and had properties superior to the standard roving that most builders were using at the time. We incorporated this change into the the hulls starting around boat # 200.

All decks however were built with Kevlar because the deck kevlar had a matt stitched to it and was dry loaded into a closed mold and then resin injected. As it turned out, the inventory of the Kevlar for the deck outlasted production.

A couple of points to consider: There was no difference in hull weight using "S glass". Kevlar is yellowish/gold color and can be seen/verified near the hull deck-joint. As Paul mentioned earlier in the thread, there is no obvious performance advantage between older and newer L28's. Hope this helps.

No problems with Kevlar hulls. However, approx. 15% of the first 30 boats built did have some dry laminate problems on the gelcoat side of the hull. The affected boats were either sent back for proper repairs or sent to a qualified local yard. Farr's office claimed the boat should have a total weight of 3950 Lbs and most boats on average came out at 4300 Lbs. We suspected we were using too much resin so we tried using less and subsequently some minor gelcoat cracking developed. Most of the affected boats were repaired properly and no structural problems have ever been reported. In hindsight, I suspect our generous interior accomodations were responsible for the additional 350 Lbs.