New & in Need

General Composites Discussions Composites Talk
#1

I guess I should introduce myself before I start asking a bunch of questions. I’m Joe Knesek from Lyndhurst, Ohio and I’m new to composites. I’m a business systems consultant by trade but have spent 20 years building & racing RC boats.

I recently finished a Corian vacuum bagging station. I’m using a Parker vacuum generator that’s controlled by Sunx digital sensors.

Over the winter I want to build my first composite boat using Divinycell skinned with carbon fiber. The link below will give you an idea of the boat’s shape. I’d like to use a braided sleeve on the sponsons but I’m concerned that the sleeve will not conform to the shape. The sharp edges are needed from a speed standpoint.

My past boat included in the gallery are skinned with 1/32 birch ply & I’ve considered using flexible carbon sheet instead of sleeving but I would like everyone’s input before I purchase anything. Any feedback would be greatly appreciated.

http://picasaweb.google.com/Joe.Knesek/2007Boats/photo#5136133137925155506

#2

I doubt that you need to use foam core for this application. There are no large flat areas that would need extra stiffness. A few plies of carbon would be more than strong/stiff enough.
I’d say just make a foam model of the boat you want to build, make molds from it, and then make superlight carbon pieces.
The current wooden boat looks heavy!

#3

Welcome to the forum Joe :slight_smile:

Your wood skin hull boats look nice, lots of attention to detail.

Do you know about the process of composites plug and mold building yet? You probably would drop a lot of weight by using just fiberglass and or carbon fiber for your boat project.

For flat braces or brackets ( if needed ) you can make a flat panel of carbon fiber then trim out the individual components from it.

But a hull yeah a mold would be best.

#4

The foam is needed to for flotation. If you build a mold it still needs to be filled with foam to prevent it from sinking in case of a crash. I have ran many professionally molded boats and they are not near as fast as the wooden boats. The edges of the running surface are rounded to get the boat out of the mold and this causes parasitic drag. The motors make a lot of horsepower turning over 35,000 RPM but no torque so drag just kills them.

The wood boat is actually no heavier than a fiberglass boat. I’m just looking to make a stronger boat because they get hit often.

I really would like to know if the carbon sleeve will bend around the sponson’s sharp edge. If not I’ll build to with rounded edges and then add flat plate to the running surface.

#5

carbon fiber cloth can conform to almost any shape you want…

you could always do an overlay if you arent worried about weight…that would make the part WAY strong without all the fuss…brush epoxy on let it get tacky, lay the carbon fiber on and brush more epoxy to wet the carbon fiber out, also you might look at hybrid fabics…carbon fiber and kevlar all in 1…

#6

Well, you got us all beat about rc boat knowledge :slight_smile: I would say just read some of the old threads or use the search feature to look around and see if you can find the info you need. Other than that i personally would be at a loss to help.

#7

Thanks for the help. I’ve been reading through the treads for a week now but it seems like most everyone is using sleeves for tube shaped parts.