Easy steps to a 70+ mph .21 hydro

[Brad Christy]

Guys,

Gregg David's scratch-built CF twin did the same thing. He had laid up the carbon in a press and then built the boat like you would a wood boat. I can't be sure, but I think he got just over one full season in it before it performed the same trick Tim K is describing. The joint between two carbon plates is not very strong at all because the epoxy used to bond them doesn't penetrate like it does in wood. A single layer of CF veil and one layer of 3/4 oz glass cloth in the joints will eliminate this failure. I would think that this would be standard building procedure for an all CF outrigger (non-monocoque).

BTW, I don't normally finish a tub to this point unless it is my own. I leave it up to the buyer to decide how "sturdy" to build the boat. Joe asked me to and I agreed (I was in a good mood that day, I guess.......... ) Even on my own boats, I will not be laying the entire radio box in CF anymore, but only at the joints where the wood grain runs WITH the joints. I still like the entire engine/tank area to be veil/clothed in like in the photos. Even full carbon in the bottom like in the photos only added minimal weight. My personal boat that I raced over the last two years weighed in at under four pounds RTR. In my opinion, the added weight is worth it for the longevity gains.

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

 

[TimD]

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[F.Orlic]

Let me start off with saying that Hummingbird is a beautifuly built boat and only true expert like Jim can build a boat of that quality, however, after taking a good look the way Tim's boat is build I'm not surprised with what happened. The joint on a Hummingbird boats is weaker because of carbon fibre than just plain wood boat. When you join two pieces of wood glue will penetrate both pieces and form a strong bond, on the other hand when you join 1/4" thick piece of plywood to Carbon fibre glue will only penetrate the wood and there is no chemical reaction to make a strong bond. Glassing a boat inside like Blackjack is best way, only thing I don't like is veil carbon used in Blackjack. Veil carbon is not even close in strenght compared to wowen carbon.

 

[Brad Christy]

Glassing a boat inside like Blackjack is best way, only thing I don't like is veil carbon used in Blackjack. Veil carbon is not even close in strenght compared to wowen carbon.

Frank,

But it's just strong enough to keep the rigors of racing from taking it's toll. I can wet out the entire bottom of my boat with one layer of carbon veil and one layer of 3/4oz glass cloth with about 5-6cc of WestSystem epoxy and it just about doubles the strength of the plywood.

We're taking this thread away from Preston. Sorry........

Thanks. Brad.

Titan Racing Components

BlackJack Hydros

 

[Mike Larson]

Hey, Guys! buildin my first rigger at present, almost complete, do you recommend the reinforcement of the tub in an all wood boat? just for peace of mind? will be eyeing this thread too, keep us goin preston.... , and thanks. mike

 

[K-ZAM]

Hey Preston since everyone on this forum has a 70+ .21 Hydro. It appears you are wasting your time explaning how. However, if you want to learn how to build

a 4lb brick **** house this is the place to be.

Kentley Porter

 

[shoboat]

Preston,

Nice job!

MS

 

[Tim Kish]

Preston

Sorry for taking your post in a different direction.

I just wanted to share what happened with my boat to help others

avoid the same problem.

I will say no more.

Tim K

 

[Don Ferrette]

I'll leave this one-

Seriously guys, Preston will make this soooo easy for everyone that Jim Benns should be swamped with boat orders. I've said it before & I still believe the 20 Hummingbird is one damn fine boat. B)

 

[Joe_Knesek]

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[izitbrokeyet?]

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[Dave Rumble]

Preston keep going with this post. I think this will truly be one of the best posted topics to date and well worth the time and effort to complete. I appreciate all the information that you have provided so far in this post and in my PM questions to you in the past.

I have a 20 Humming Bird and am about to finish the setup on the hull so I am all eyes and ears for the next update on this post. I also feel that putting as many people on the same speed level as possible (70 mph) will do nothing but push the technology improvements on the 20 Hydro to a new level.

Whats the fun of having only one or two 20 Hydro's on the pond smoking every ofther boat on the pond. I would far rather see all boats in the heat running in the 70 mph range in the race. That would be wicked, and far more exciting and entertaing to the racers and future racers that would be spectating the event.

Thanks again and keep up the good work!

 

[Preston_Hall]

I just typed for a half of an hour and hit the esc key to loose it all. I'll come back later and straighten some of you out.

 

[Don Ferrette]

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[tracerbob]

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[Don Ferrette]

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[Joe_Knesek]

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[Don Ferrette]

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[Joe_Knesek]

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[Brad Christy]

Kevin,

I never mentioned anything about performance. I have my way of getting there, Preston has his, you have yours. I was only agreeing with Tim K on his issue. So was Frank.......

BTW, I bet if Andy Brown were to post this thread, he'd say you just GOTTA start with an SGX and a MAC...........

Hey Gambrel! What would you suggest?

Thanks. Brad.

Titan Racing Components

BlackJack Hydros