My first boat project 23' cat

[Robin Smith]

First I would like to say this is a great website. I have learned so much already from the rest of y'all that I felt I should start by saying THANKS!!

I am in the descovery stage in building a 23'- 25' cat.
Thanks to someones posting I think I am going to try my own version of a Bobkat w/ HySuCat foil for the hull design. I have so many questions and so much research to do that I thought starting this post would be advantageous to myself and other to follow as I progress.

1. Reading a post here you talked about framing and your conclusion was T stock but I do allot of building and we use square tube allot and I that would be my choise of frame material 1x1 w/ .125" wall thickness. What is your input on this?

2. Foil designs and my greatest concern about this area is debrie and will a foil stand up to impact if it hits something in the water?

3. I wish I could find the posting by Small Cat that had this design in it I would attach it here is this a really good design as was said in post?

[Robin Smith]

Hi back with more question.
1. Decking, I was going to use diamond plate then the guys at work reminded me how even it when wet can get real slick. They recommended spray on stuff like what is used for truck bed liners. How is this product going to effect the metal? living in Maryland it gets real hot and I am not sure weather coatings and paint will help or cause more problems.

2. What works best for sound deadening material?

[marshmat]

Fun project, I hope!

A big issue with square tube is that water and undesirables, if they get inside, can corrode it fairly quickly. What metal are you using?

How a foil stands up to impact depends on its construction; rudders of all kinds can snap, but in general there's a tradeoff between strong and low-drag.

For nonskid on my boat, I just used the same paint as for the hullsides and deck, only I sprinkled a bit of fine silica sand (sold for pool filters) on top of the wet primer. It's lasted 5 seasons with no maintenance and works incredibly well.

Sound deadening.... for an engine? Fibreglass batts/tiles are common and effective, but they can soak up water... perhaps Roxul? Styrofoam's common too, and adds flotation.

[Robin Smith]

Aluminum is going to be material used and the materials used for sound deadening must not hold water or effect aluminum as a resolt of using it.

[crawdaddy031]

Sound deadening can be acomplished with the closed cell polyurethane foam with aluminum backing found in the big depot stores. Seal the open sides with aluminum flue tape and also can be used for taping joints between panels. Panels from 3/4 to 2 inch thickness can be had. The foam will be either yellowish or a blue color with aluminum skin. I second the opinion of silica in the primer. The use of Rhino lining as a nonskid is a no going back without serious work experiment.
Jim " on the hard today"

[Robin Smith]

I found the link which has the hull design I was thinking of triing. It's at the bottom end of article and was provided by Small Cat to which I say Thank You.
http://www.hypermax.com/multihullsmag/magazine/articles/cat%20hulls/performance_of_cat%20hulls.htm

comments are welcome?

[Robin Smith]

I hope this comes up never did it before. foilwing (http://)

[Robin Smith]

The wing above is Aluminum 3/4" thick 12" wide and 42" long has a support for center not shown 8"x1/2" thick w/ a deck reenforcement of 12"x12" on top. welded to hulls and deck. will this work for a wing

[Robin Smith]

I have started making my first model of my catamaran yesterdayand I am perplexed about one thing!

1. Is there a way to know if your design is too top heavy? With a beam of 100" wide and a length of 25', the deck is going to be 2' above the water. The things below that line will be the twin outboards 150hp, twin fuel tanks 110gals each, water tank 35gal, waste storage tank 35gal, twin fish lockers, wire hoses, pumps, ect. This craft will be 105" tall.

Wow, I think I just answered my own question but would still like to be sure. That is a fair amout of weight below deck.

Please comment on what you see so far? Thank you