Carbon fiber or fiberglass

[revkev91]

Hi guys im looking at buying a hull for a cat build. Just want to know is it worth the extra money for carbon fiber or should i just stick with a fiberglass hull.

[tlandauer]

Hi,
Please have a read, some very excellent discussion:
http://forums.offshoreelectrics.com/...589#post614589

[Luck as a Constant]

carbon fiber is awesome... worth the money? yeah...
only downfall is that carbon fiber blocks radio signal... but plenty of guys have solved that problem. also, you can lay it yourself into a fiberglass hull for added strength

[keithbradley]

It REALLY depends on the hull you are talking about. Some carbon hulls are very thin and while lightweight, they offer little strength without reinforcement. Many carbon hulls and carbon fiber materials (like cheap CF plate) are made with cheap polyester resin and aren't really any stronger than FG. Some fiberglass hulls are thick and vacuum bagged and offer more strength than a lot of CF hulls. To really make a fair judgment, you have to be sure you're comparing apples to apples. With that said, properly done carbon is NOT rivaled by fiberglass.

[revkev91]

The hulls I was looking at were the fightercat shocker, fantasm, cheetah or the kbb 45" mystic. But i live in Australia and it becomes pretty expensive to get them here unless someone knows a cheap way to get them here or if i can buy them somewhere here.
There is a place in Australia, rc boat bitz that sells the genesis and zonda hulls in CF but not sure of the quality.

[ls1fst98]

The kbb 45 mystic is far above those other 2. Not that they aren't good, the mystic is just built very very well. Almost all the fightercat/tfl hulls even in carbon will require added inlay to make them strong enough.

I have a cf shocker, and in the light you could see through the carbon, and it was the "heavy layup".

[Darin Jordan]

It REALLY depends on the hull you are talking about. Some carbon hulls are very thin and while lightweight, they offer little strength without reinforcement. Many carbon hulls and carbon fiber materials (like cheap CF plate) are made with cheap polyester resin and aren't really any stronger than FG. Some fiberglass hulls are thick and vacuum bagged and offer more strength than a lot of CF hulls. To really make a fair judgment, you have to be sure you're comparing apples to apples. With that said, properly done carbon is NOT rivaled by fiberglass.

Boom! But, the right answer from Keith Bradley would be what I'd expect!

[NativePaul]

I thought the cheap Chinese carbon boat makers are using vinylester resin to lay up with, which works fine though it is not as strong as epoxy and is much cheaper. I was under the impression that polyester would not wet out carbon properly and could not be used, though I have not tried either myself as epoxy is cheap enough in the quantities that I use?

How big a hull do you want and what do you want to do with it? ETTI and Tenshock both use predominantly a single layer of carbon in their boats, but using epoxy resin and have decent fillets for sharper angles than I have on my H&M or MHZ hulls. They are not SAWs hulls and certainly wouldn't stand up to an 90mph blowover, but are are about as light as you can make a boat while being rigid enough not to have power sucking flexible running surfaces, and you won't find a commercially available hull that is faster on the limited power that they are designed for, both do glass versions as well and the glass versions are both heavier as you would expect, to get the same strength needed from a weaker material.

[IRON-PAWW]

I have the v1 Zonda hull from RCBB. That hull is frighteningly thin and lets a whole lot of daylight through. The v2, which is the one you get now, is better apparently. Talk to Joe Dimech at RCBB and see if he'll inlay it for you, if you want that. Keith's hulls are better though, no question. In my opinion - talk to Keith about landing one of his hulls here. It isn't as bad as you might think. I ordered some stuff from Keith without issue. If you want as much speed and strength as is doable out of the boat - talk to Keith. If you're just after a lower cost weekend runner, and don't want to upgrade it, then the Zonda's are fine. But everybody always says initially they don't want speed :). Spend the money once and spend it well I would.

[keithbradley]

The hulls I was looking at were the fightercat shocker, fantasm, cheetah or the kbb 45" mystic. But i live in Australia and it becomes pretty expensive to get them here unless someone knows a cheap way to get them here or if i can buy them somewhere here.
There is a place in Australia, rc boat bitz that sells the genesis and zonda hulls in CF but not sure of the quality.

The fighter cat hulls are definitely thinner, but are also completely different in design, so your choice may be more relative to your needs than anything. The radtek hull will be the best choice if high speed, scale looks, and twin drives are important. The Shocker and Fantasm are lightweight, easy to setup, and don't require a lot of power. The Cheetah is great for running ovals.
If you plan on building a single drive boat, the TFL hulls are going to be a better choice due to the sponson design.

[keithbradley]

I thought the cheap Chinese carbon boat makers are using vinylester resin to lay up with, which works fine though it is not as strong as epoxy and is much cheaper. I was under the impression that polyester would not wet out carbon properly and could not be used, though I have not tried either myself as epoxy is cheap enough in the quantities that I use?

Vinylester resins are for the most part a compromise between polyester and epoxy resins. Technically, neither Poly or Vinylester resins should be used with carbon fiber for structural applications, but that doesn't stop anyone from cutting corners to save money. There are a number of hull manufacturers that use poly resin even with CF, and A LOT of carbon plate out there made with Poly. I have polyester infusion resin that I use when making a test part - that is, a part that will not be used, only molded to test a method or process I'm experimenting with.

The cost seems negligible, but when you start going through resin in 5 gallon quantities, it becomes apparent why some would use the cheap stuff. It keeps cost down, and most people only identify carbon fiber visually, rather than by it's integrity. It's also impossible to compete with prices offered by those using poly resins, because their retail price is often less than the material cost to make a proper laminate. It ends up being a choice between making a product that will compete in the current market, or making something that you know is better.

[jcald2000]

Absolutly correct Keith!

[revkev91]

I want a hull to build as this will be my first build i don't want to spend to much money but i want a hull that will be strong and reliable . I want it to be fast but doesn't have to be a record breaker and it will only be used for some weekend fun and if it can handle a little bit of chop.

Not sure if i want to run twin or single set up. Is twin setup a lot harder to maintain and is it just twice the cost?

[keithbradley]

I want a hull to build as this will be my first build i don't want to spend to much money but i want a hull that will be strong and reliable . I want it to be fast but doesn't have to be a record breaker and it will only be used for some weekend fun and if it can handle a little bit of chop.

Not sure if i want to run twin or single set up. Is twin setup a lot harder to maintain and is it just twice the cost?

Twins cost more. They can offer more reliability at the same power level, and a different driving experience than singles.
Singles are easier to build and easier to afford.
Regular maintenance is for the most part irrelevant. It's not that hard to pull two flexes. Long term maintenance, like changing motor bearings, motors, ESCs, etc. would be doubled when the time comes, but it's possible that the interval could be longer compared to a single also.

There are really only two things to consider. Cost, and performance. The "harder to maintain" and "just bling" sentiment usually comes from people who don't own any twins and wouldn't know. Ironically, the same people are the first to cry foul when they get their rear ends handed to them by a twin.

[montymike]

And the coolest sound from a twin...