i was just thinking

[Lay26]

since i have the time.. was really wondering why we don't see to many composite material riggers? I currently looking to do some building and is it just me or is the price of the birch ply going up? Now that has me thinking of using fiberglass or carbon fiber. what are you guys thoughts on the pros and cons of building the composite boat vs building the current wood hull.

 

[dwilfong]

https://www.boulterplywood.com/Ocume is the lightest ply.
Look at the weight difference in the 4x8 sheets.
all most half the weight of all the other stuff.
I got 2 2x4 sheets shipped to me in FL. for $85

 

[dr gary turner]

I like a composite hull of .030 carbon fiber on the out side, dyvinicil 4oz(thickness depends on the size of the hydro) and 1/64-1/32ply on the inside

This sandwich is vary strong and light.

 

[Terry Keeley]

You can't compare composites to that "naturally occurring cellulose product"!

 

[Lay26]

i remember when you built that hull it has to be over 15 years old and it still holds up...right did anything fail over the years of racing....if you built a wood boat like that would it have gained weight Terry?
i think what I'm trying to settle in my mind is if its worth all the work build a composite hull from plug to finish be worth it

 

[Terry Keeley]

i remember when you built that hull it has to be over 15 years old and it still holds up...right did anything fail over the years of racing....if you built a wood boat like that would it have gained weight Terry?
i think what I'm trying to settle in my mind is if its worth all the work build a composite hull from plug to finish be worth it

Composite boats are about the same weight as lighter wood boats but much stiffer and way more durable. If you get a scratch in the paint you don't havta worry about it soaking up water and oil like a sponge! You don't need to mold them, you can build like laminated wood but with cloth, my SAW boats are done this way.

My heat race boats are going on 20+ years for the tubs, I built those with carbon "braid" over foam plugs in '99. I've had a few different sponsons/rears/ski configurations but haven't changed them since about '06.

My SAW boat is actually on it's 5th tub with several sponson/ski configs, I broke the last two and built the most recent one with "S glass" hoping is gives a little before breaking. Build photos are here if interested: Outrigger Build

Here's a cool vid on the different cloths and their qualities:

 

[dwilfong]

Ocume BS 1088 is water proof.
It is not aircraft cheep ply wood you get at the hobby shop.
It is made to build wooden boats.
You buy the right stuff and you will get what you pay for.
https://en.wikipedia.org/wiki/BS_1088

 

[Lay26]

Dwil fong i hear you on the importance of material choice.
Terry the way your saw boat broke( was that a laminated foam hull) is something I've seen over the years with the wooden riggers especially when they going really fast. Hence the thought if i make a mold of the tub and make it out of composite materials...i could potentially avoid having to deal with that kind of damage..but why do you feel that u don't need to make a mold? i reviewed that video on the carbon vs kevlar and fiberglass. I see that s glass should be seriously considered. I fugure the time it takes to build a wooden boat i could have a mold built one done much quicker once the plug and mold is done...and thats what i think im trying to get away from constantly building wood boats. Thanks for the imput guys

 

[Jeff Lutz]

Ocume BS 1088 is water proof.
It is not aircraft cheep ply wood you get at the hobby shop.
It is made to build wooden boats.
You buy the right stuff and you will get what you pay for.
https://en.wikipedia.org/wiki/BS_1088

Most of that material I’ve found is 6mm .236” thick. Is yours true .250” thick ? Throw some calipers on it when you get a chance please. Jeff

 

[AlexPoca]

I have a few carbon riggers now to many thanks of Terry Kelly for all his guidance.
If planning a vacuum bagging It can get a little expensive with all the consumables that are required for a layup that just go into the trash when done. But end product is rewarding and durable.

 

[dwilfong]

Most of that material I’ve found is 6mm .236” thick. Is yours true .250” thick ? Throw some calipers on it when you get a chance please. Jeff

It is the good stuff........
Not my first time buy from them.

 

[Terry Keeley]

Terry the way your saw boat broke( was that a laminated foam hull) is something I've seen over the years with the wooden riggers especially when they going really fast. Hence the thought if i make a mold of the tub and make it out of composite materials...i could potentially avoid having to deal with that kind of damage..but why do you feel that u don't need to make a mold?

You could make a mold for sure but how to seam it? Frank O used to make a top and bottom IIRC, or you could make the top and sheet the bottom (that's how I do my SAW sponsons). Lots of work tho to make a plug/mold and then tub.

Or you could make a one-off foam plug like my heat boats, cover it with a sleeve and melt out the foam: CarbonSleeves

Lot's of options.

 

[Lay26]

well after two month....I realize why we don't see many composite rigger hulls being produced...i understand now. it takes a lot of time, material, patience and hard work. mold making is a lot of sanding, a lot of prep and getting on the right learning curve. you have to do your research to understand how things work. you will have trail and failure and that means wasted material which means your cost is rising. Vacuum bagging is another level its a bit more material and one time usage. these additional cost makes just build a wood boat more appealing to the masses but while the initial cost of composite manufacturing a bit higher i think the end result of having a solid part from a mold will be worth it...

 

[brad nichols]

The Ocume BS 1088 Is metric sizing and the smallest I have found is 2 mm.

Brad

 

[RaceMechaniX]

Most of the tubs I build myself are Birch ply with carbon inlay. The tubs are all designed in CAD and the plywood is laser cut making it very easy to assemble and try new designs. Comparatively speaking the hulls are pretty inexpensive to build, I estimate about $220 for the laser cut wood and carbon. I am on my 9th iteration of the hull shown below.




Somewhere between the 4th and 5th iteration of this SAW design I had a hull cut entirely from pressed carbon/Divinicell sandwhich. It was horrifically expense at $2400 for the CNC routered pieces. It is fairly light and probably strong enough to survive any crash. It's a shelf queen now and reminder to work in cheap materials in till the recipe is nailed.

 

[BobHorowitz]

Tyler,
What's the tank for?
Bob

 

[Lay26]

Wow Tyler thats a bad looking boat....i see the cost really added up on that one. I think the tank is there to put some weight on the prop

 

[RaceMechaniX]

The tank in the rear was an attempt to make a closed loop cooling system. There is no water pickup in the boat. I would fill the tank and flush the system with ice cold water and make passes. I learned that the tank was only good for a single pass, but the pump worked well. So today I have an Octura streamlined water pickup in the middle of the hull and the small BEC powered pump to cool in between passes. The pickup is out of the water when the boat is on plane. When it slows down the pick helps prime the pump and circulate water through the motor and controller.

 

[Lay26]

So here's an update on what I was thinking...I built a new tub from the best boat I have...the slingshot...however I wanted to put a Quick draw in it so I made the tub 5 1/2 outside so that I could get 5" on the inside. Had some great info passed on to me for materials. Thank you sir. After making the plug and a lot of sanding, painting and waxing I finally made the molds. This hull is the first one I did. It was a great learning experience. Its not perfect but I'm working on it. Currently I'm working on the sponsons the cowl was done to fit the wider tub. Rear sponson will also be carbon fiber as I made a mold for them as well. The fronts are wood because I have an idea for the bottom I want to try. I want to see if it works the way I'm thinking.

 

[Terry Keeley]

Very nice! You jumped right into the deep end.