Vinylester+Knitted Fabrics

[sharkeymarine]

The combination of these 2 products are holding up well under severe conditions, check out the PICS http://pages.zdnet.com/sharkeymarine...arine/id6.html

[richard]

What makes Vinylester better than Epoxy for this construction? Is it a matter of thickness/workability with particular fabrics, or is it more cost?

For that matter, how much better is vinylester than polyester? I know I read something about it being less prone to develop blisters, but what else is better about vinylester? I don’t hear about too many amateur boatbuilders using vinylester – mostly either polyester or epoxy and I'm curious why.

[sharkeymarine]

Vinyl vs Epoxy , Cost is a major factor, workablity that too. As far as them both? Epoxy is superior. Vinyl vs Poly? A night and day difference. Again cost is a factor because afterall, Vinyl has an Epoxy base. Once I worked with the Vinyl, it is hard to go back to Poly. Poly creates alot of heat in multi laminants and is very brittle. For example: I took a single layer of 1708 biax fabric and wet out 2-4ft strips one of each. After they cured I gave each a flex test. The Poly strip made a bend of about 90 degrees and cracked right in half. The Vinyl, I was able to bend a full 180 degrees and touch the sides end to end. That convinced me to spend a little more for the resin and save a little in how much glass was needed. Currently the sides in my 13 ft Vee-Bottom are 1/8 of an inch thick. 1 layer of 3/4oz mat skin and 1 layer of 1708 Biax Knitted fabric. The boat has run 75 miles in the NPBA NYC Poker Run as well as 85+ miles in NJPPC's Poker Run which in part was in the ocean, and came back w/out even a stress crack. http://pages.zdnet.com/sharkeymarine

[Jeff]

Very nice

To go that fast in a 13' boat must be quite a thrill! You really can't beat a small boat for fun.

And your hull is beautifully done too!

But now I have a question for you: what can you tell me about that small catamaran racing next to you? I built a small 12' cat as my first project, and have never seen a comparable boat (in design and size), until now...

It looks like yours is pulling ahead, and the handling of a small v probably can't be beat by a small catamaran, but I would still love to know more about that catamaran since it looks pretty similar to my own.

[sharkeymarine]

Jeff, thanks for the kind words. The 13ft cat was built by a company called "FUNBOATS,INC." of Point Pleasant, New Jersey, USA. It is actually a scaled down version of the 30 ft SHADOW offshore cat that this guy used to work for. Since then he now is in Florida somewhere still doing fiberglass work, I don't know exactly where. The boats were fun to race against but they had a real hard time making turns without barrel rolling over. That was another reason I tried to run the inside lane because usually they will flip to the outside. All in all it was a competitive boat. One guy had kept upping his horsepower until the boat finally reached over 80 mph. He stated that that was when then tunnel began to work. Makes sense, the 30 ft boat did the same thing. It too didn't run well until you went over 80 mph. Sounds to me the tunnel needed more compression to carry the boat at lower speeds. Do you have any pics of yours??

[Jeff]

My 12' cat was built in 1995 and 96. I probably shouldn't have said that it looks that similar, as my lines were a bit simpler. But a lot of people have asked me where they can get plans for a similar boat, and to date, I have never seen a comparable. The 12' cat was my first boatbuilding experience, actually the first time I ever used resin or fiberglass, and was done in pretty limited time flowing around other events, but it was still a great experience.

I should get a larger outboard one of these days and see what mine has in her, but the problem of poor turning was already there at 35 mph (not dangerous, but not the feel I wanted either), so I can only imagine 80. The lack of an optimized hull for cornering was made worse by too much weight too high and the worst engine config possible. But I suppose I should have realized that the difference in scale and weight distribution compared to a larger cat would call for some major changes to make a smaller cat corner better. On the other hand, since it was my first project, it still went pretty well all things considered. Now if I can only find time to get back to that type of project...