carbon fiber vs fiberglass reinforcement

[Johnc]

OK, just asking the experts,
CF is expensive (with epoxy), is it worth it compared to just using fiberglass cloth and epoxy (if just to do the seams, inside transom)?
Also: on the zonda 41" how in the world will are you be able to get the reinforcements up to the points (bow) of the cat.
Yea: did some searching on hear, but probably used wrong wordage to find what I'm looking for.

Enjoy the weather (yea right, live in bi-polar MI and see what its like)

John

[Mike W]

Simple answer. No. It offers slightly more stiffness but in a hybrid layup its value is questionable at best. Benefits are primarily appearance.

I switched to using glass. It is transparent so you can more easily see any trapped air while laminating and the end result will be a better lamination. Carbon conceals trapped air.

Working up front is easiest if you tape a flashlight to the hull to illuminate the area and then apply the material using a brush taped to an extension dowel or paint stick. Practice applying your layup dry to determine how far you can effectively reach to both prep and apply your overlay.

Another method would be to pour a warmed resin mixture in the front of a warm hull and tilt the hull and brush to coat the seams as possible while the epoxy viscosity is low. One big blob in the front only doesn't do much for strength. If can do one side at a time and keep it evenly distributed around the seams until it gels that is best.

[fweasel]

Inlays aren't about covering every square inch of hull surface area, they're about strengthening weak points in the hull like seams and long flat surfaces that flex from a lack of rigidity and support. The sponson tips are indeed the hardest parts of a cat hull to reach internally, but don't need the same attention that a tunnel floor, side walls, or front deck so, all of which are significantly easier to work on and access. The multi-countour shaped portions of a hull are naturally stronger that big flat spots, and as such, don't yield the same benefits vs. the amount of work required. I use a mix of epoxy and chopped carbon fiber and do small pours into each sponson tip and another across the bridge between the two, letting them cure while the hull rests upright in a water bath to control temps. I reinforce the side seams as far forward as I can reach with my tools for a given hull. Using a narrower tape for the seams is much easier to work with than large, full sheets trying to cover a lot of area at once. The large pieces I use cover the tunnel, floor, and as far up the sides as I can reach, all while maintaining a reasonable size piece of cloth that I can actually work with.

[Johnc]

Thanks guys,
All info is taking in:

Mike W, good idea about using dowels/paint sticks as extensions and tilting the boat as needed

Mr. fweasal: Been following your thread "Miss Geico 29 v3 winter build" and plan on following through with what you have done so far (other than I'm going to use FG) Now I need to get some CF plate for the bow stringers like you have. $$$ never ends.

Next project on this thing is the transom where the rudder attaches (looks like that could be a problem in the long run) the bolts come through the seams (hmm) not a good design, should have gone with vertical bolting (that would have helped holding the seams together) just my thought.

Love this Michigan Bipolar weather (65deg today, snow tomorrow)
John

[NativePaul]

Carbon for extra stiffness, whatever the hull was originally made from for extra strength.