20 foot race boat (NZ)

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Chilli Dog
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Re: 20 foot race boat (NZ)

Post by Chilli Dog »

deck rails and seat
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Chilli Dog
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Re: 20 foot race boat (NZ)

Post by Chilli Dog »

this boat took me a couple of week ends and ten nights after work to complete , it's pretty rough , and here it is at scrutineering yet to be launched
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THCL500J8
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Re: 20 foot race boat (NZ)

Post by THCL500J8 »

Chris, Thanks you.
its so brilliantly simple. (the boat not you, ok your also brillant) (Charles payed me to say that)

Its what a lot of us want in a seagull boat, Can be raced and stand a chance, but be used as a normal boat with the grand kids or the missis if need be.
I think there might be a few Chris Steele specials popping up around the place. My only question is what thickness ply did you use?

Thanks for shearing and the building tutorial most helpful.
TC - 1960 LLS - 1961 LLS - 1966 THCL - 1968 EFNRL - 1986
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Chilli Dog
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Re: 20 foot race boat (NZ)

Post by Chilli Dog »

the ply I used is 6mm , and thank you for kind words though I point out Adrian Pawson deserves a fair amount of the credit too for his input .
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chilli dog under way down the Waikato on launch day
chilli dog under way down the Waikato on launch day
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Chilli Dog
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Re: 20 foot race boat (NZ)

Post by Chilli Dog »

the decks are 6mm boat ply as is transom . (not bendy ply) and I used 20 X 20 for the deck to hull join to save time
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Charles uk
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Re: 20 foot race boat (NZ)

Post by Charles uk »

Thanks Chilly a very informative thread, I wonder how it would go with one of Adrian's Sports on the back of it, that might well demonstrate it's potential further up the speed curve.

Nice piece of work, & looked very good gliding down the river, from the bank, where my engine building ability had placed me!
Make it idiot proof and someone will make a better idiot.
THCL500J8
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Re: 20 foot race boat (NZ)

Post by THCL500J8 »

Funny i was wondering how it would run with my 102cc "almost seagull" a 4hp Mariner / Yamaha a great little motor.
TC - 1960 LLS - 1961 LLS - 1966 THCL - 1968 EFNRL - 1986
Michael
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Re: 20 foot race boat (NZ)

Post by Michael »

I like it and I suspect it will go well with moderate power like that of a Seagull. But with the soft chines, and have to wonder if the speed will increase much with a larger engine? Not sure that it will ever plane, surf, yes.
One other comment. I note that your joint goes from gunnel to gunnel, which to me makes the joint a weak spot, even though you covered whole boat in glass. When I have built similar boats, I would stagger the joints for the sides and bottom so they do not overlap each other.
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Chilli Dog
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Re: 20 foot race boat (NZ)

Post by Chilli Dog »

I used tri axil cloth on the inside of the joins . weak they are not . I get your point Michael , but this boat was also made in a very sort space of time in order to make the race start , every time saver cut I could take helped. even joining the ply . i did using boat cloth to tape the deck to the hull however
As for would this boat plane ? I'm sure it will . I'll locate a little more horse power at some stage and let you know .
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Michael
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Re: 20 foot race boat (NZ)

Post by Michael »

I was just thinking about your boat rules - in particular the 3.5 length to width ratio. Working out hypothical numbers, this makes for quite a wide boat. ie a boat with a length of 14' would need to be 4' wide. Have I got that right? Also, where do you measure width - at widest point?
Just to compare to my boat, it is 24' long, 2' 4" wide on bottom. I have hard chines and side are angled outwards, so a guess would be that max width at gunnel would be about 3' 6"
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Chilli Dog
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Re: 20 foot race boat (NZ)

Post by Chilli Dog »

well done michael you seem to have grasped the ratio aspect , and if you read my post I don't explain why the rule is because I don't know . but i guess it to avoid canoes and making older style clicker types obsolete.
at the widest point is my guess as to point they are measured .mine is 1800 mm
Your boat type is common in bermuda (allwood style ) if you had read my thread you'd understand why I built my boat in this manner.Stable , dry and capable of carrying a number of people
But what I didn't say was no hard chines and the reason for that is unless you can balance horse power , ballast and design they often suck more power than they provide lift benefit of . we use stock motors on the whole with less power , my boat will find it's own level a lot like a racing yacht . Thanks so much for posting a picture of you boat .
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Last edited by Chilli Dog on Thu May 15, 2014 8:48 am, edited 1 time in total.
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Chilli Dog
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Re: 20 foot race boat (NZ)

Post by Chilli Dog »

Tinker and I
Thanks to Nina at working edge pictures for the photo :)
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Charles uk
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Re: 20 foot race boat (NZ)

Post by Charles uk »

Michael, the 20 foot class in NZ has very different rules to yours,

New Bermudan Flea Class: mono hull, minimum length 12 ft, max 20ft, one bow, no outriggers, two persons onboard with minimum combined weight of 150 kg, spare seagull engine can be used to make up weight, standard engine, no modifications, models 102, century and silver century, prop modifications allowed using seagull props, cavitation plate allowed.

So the only way to find a speed gain is hull design & perhaps some prop work, just look at the pictures of this hull in motion, look how much water it's pushing out of the way when it's going, I'g guess someone had been studying racing yacht design.

The Kiwis are at the front in yacht hull design & I know Chilli has worked in that area, if your budget won't cover a 20 kilo carbon composite hull, this radical hull might be the way to do it on the Waikato, which has very different conditions to yours.

One thing about the Kiwis, is that they think outside the box & some of it works real well!
Make it idiot proof and someone will make a better idiot.
Michael
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Re: 20 foot race boat (NZ)

Post by Michael »

I have no problem with the design, but do think it best suited for low horsepower engines.
I do agree that this design leaves a very clean wake.
I would be interested to know how it would perform with say a 15hp engine.
Have you tried that or are you thinking about trying it.
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Charles uk
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Re: 20 foot race boat (NZ)

Post by Charles uk »

I don't think 15hp was even considered when that hull was designed & built, I got the impression it was designed as a displacement hull to take full advantage of a stock Century's limited power output.

The Waikato is two & a bit times your RISR, so there are a few DNFs & the odd POM who DNS!
Make it idiot proof and someone will make a better idiot.
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