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Old Mar 24, 2015, 12:13 AM
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Originally Posted by TedFlack View Post
Thanks Dick.

I started with two strips along the keel centerline and then did most of the strips from the sheer. So basically the sides are all parallel to the sheer. There are eight strips from the keel in total and the rest come up from the sheer.

I used lot's of rubber bands and no pins because I didn't want all the pin holes and planned on having a clear finish. And I mean LOT's of rubber bands.

I have no idea if that is the best way to do it but it seemed to work OK.
Hey Ted,
Congrats on your beautiful build.
If you don't mind, I have a quick question as I am trying to choose between a few plans, I was wondering what the beam and beam at waterline is on the Alternative. I know it is slimmer than the BP which is intriguing to me.
Also, please do let us know how you find her performance.

All best,
David
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Old Mar 24, 2015, 12:16 AM
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If you happen to have access to a vacuum chamber! The standard way to remove water is to vacuum bake ie lower the pressure and increase temperature. And all the water will be pumped away.
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Old Mar 24, 2015, 02:47 AM
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Joined May 2012
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Leaky IOM Keel

Thanks John,

I'll try both of your methods I think I'll put the keel in a box with glass top in a warm/sunny area plus add the damprid it just might be the trick.

Thanks for the input and potential solution

Tony
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Old Mar 25, 2015, 02:58 AM
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Australia, VIC, Paynesville
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An excellent solar 'oven' is an open white cooler/esky/polystyrene box. It is amazing how hot parts can get in one of those. It is a nice pervading heat that is protected from cooling wind. I used to use this to cook off small parts to ensure complete chemical reaction and to bake on paint.

Just don't leave stuff too long as I've had metal parts get hot enough to melt into polystyrene cooler box, so be warned!
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Old Mar 25, 2015, 09:06 AM
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Calgary Alberta, Canada
Joined Feb 2008
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A couple of options I used in my years of windsurfing :
Tissue paper stuffed in any opening and a fan to increase airflow around board can assist the speed of the evaporation process here. Be patient and wait till fully dry, this can take from days to several days or weeks.
centrifugal force can also work, make a turn table and spin fin with hole facing out.

Good luck
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Old Mar 25, 2015, 09:18 AM
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Minnesota, USA
Joined Aug 2002
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Originally Posted by coolmobility View Post
An excellent solar 'oven' is an open white cooler/esky/polystyrene box. It is amazing how hot parts can get in one of those. It is a nice pervading heat that is protected from cooling wind. I used to use this to cook off small parts to ensure complete chemical reaction and to bake on paint.

Just don't leave stuff too long as I've had metal parts get hot enough to melt into polystyrene cooler box, so be warned!
Did big cat "beach repairs" on boards and rudders. Slide into a black, plastic garbage bag. If you are careful, you can use your hands on outside of bag to smooth it out - and then put a fold at open end - secure with a rock. If done carefully, it is almost (almost) like getting a vac-bag finish. You can adjust heat/temp inside by the opening of the bag and adjusting.

Kind of like leaving your plastic parts in the back car window and finding the sun warped them. Be careful with anything black as it rapidly absorbs heat.
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Old Mar 25, 2015, 11:50 AM
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Shanghai, China
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Am back with Rhino Plus!

Lol~
crazy days saw me revising preliminary drawings of new boat design for 2015.
this is a heavily tweaked version of last year's Rhino thus called Rhino+
Again, before final 3D plans are drawn, I like to get hands on feel of hand drawn sketches which can give me immediate results without disrupting computer command input.
Here are some pics of freshly baked paper works, comments/discussions welcome and appreciated
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Old Yesterday, 02:13 AM
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Originally Posted by triplane View Post
Lol~
crazy days saw me revising preliminary drawings of new boat design for 2015.
this is a heavily tweaked version of last year's Rhino thus called Rhino+
Again, before final 3D plans are drawn, I like to get hands on feel of hand drawn sketches which can give me immediate results without disrupting computer command input.
Here are some pics of freshly baked paper works, comments/discussions welcome and appreciated
Great to see you again Triplane, obviously you are pleased with how your double chined Rhino hull went, and again you are building a sexy different flat/curved unconventional bulb. Looks great and from my square counting is 165mm beam.

Best of luck and hope it is an improvement on your original Rhino. We expect more pics of your excellent quality and well-planned build. Happy sailing now you should be thawing out after your Winter.
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Old Yesterday, 04:51 AM
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Hi Colin,
Nice to catch you again.
This time I will build a wooden hull proto first. I need time to trail for so many new ideas.... well keep it updated anyway.
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Old Yesterday, 06:10 PM
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Quote:
Originally Posted by triplane View Post
Lol~
crazy days saw me revising preliminary drawings of new boat design for 2015.
this is a heavily tweaked version of last year's Rhino thus called Rhino+
Again, before final 3D plans are drawn, I like to get hands on feel of hand drawn sketches which can give me immediate results without disrupting computer command input.
Here are some pics of freshly baked paper works, comments/discussions welcome and appreciated
Hi Patrick,

Welcome back.

What would be really interesting is a comparison between the new design and the original Rhino i.e. the changes you have made and why?

I take it you think the twin horns idea works in practice and is not just a matter of individual aesthetics?

Also, I would be interested in your reasoning on going for the double chine. As an aside, I would note that Frank Bethwaite (erstwhile revered and much famed NZ/Australian guru of all matters technical) did some experiments comparing sharp chines to chines with a pencil round. He found the sharp chines gave a 2 per cent advantage, which is considerable in the scheme of things. It seems to me that multi-chines would tend to smooth out this knife-edge effect, cancelling out to some extent the reason for having a chine in the first place. Discuss, please...

I note that your 2015 design could hardly be more different to mine. I will be intriguing to see which, if either, is the more successful. It would be fascinating to put them up against each other. Now there's a thought.

n
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Old Yesterday, 11:06 PM
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Hi Nick.
Try to answer your questions.
I can't recall accurately who'd invented multiple chine concept but saw Jeff Byerley experimenting this on his various designs starting from a M(10r maybe?) called JAB. While not 100% sure his reason to do this, I have my own understanding.
Back in 2013, after sailing against local BPs for couple of years, I want to design a boat with wider performance scope (i.e. light winds, flat water). My approach is to make the rocker line flatter(thus shallower draft is obtained) while retaining sufficient buoyancy in forward sections. To achieve this, I need to enlarge the radius of underwater lines of the shadows and limited WLB. The balance is fulfilled in a manner of introducing a secondary chine just below WL to force the large radius "stop" in place of ideal beam width. I also flattened shadows of stern sections to make it easier to plane when running downwind, and this idea has proven itself very effective. (many times saw Rhino closing gaps between leading boats and even made overtakes in downwind leg) . Besides these arrangements, I also considerably lowered the height of the main chine to maximize the prismatic effect. That is to say, when heeling in same angle with other designs, Rhino will have 2-3 chines working under waterline against 0-1 that of others.
Now a bit more on the new "Plus" design development:
I have sailed Rhino in various conditions and regattas/training sessions in the year of 2014, through which the basic theory of design is proven to be in the right direction. The motivation for me to get my hands on Rhino+ is the original design 's performance was less ideal on choppy waters with that "too fat" bow shape, and that shape also makes boat somewhat sticky in drifting conditions.
To iron this wrinkle out, the new design uses much smaller radius on forward sections to get a finer entry. With reduced volume and still seeking for good balance, I have the forward rocker line deepened a bit and C of B moved aft with widened transom. Flatness @ stern is saved with secondary chine fine tuned to improve water exit angle.
Other features of new design including extended upper chine at bow with flare which I hope can make some help to minimize wet surface in that area thus keep the wave resistance low. When heeled in certain angle, it also should be helpful to aid the hull pointing at a higher angle.
As for the horns, I think I have some explain somewhere else in this thread. (maybe in one of "Torti"'s post). The major reason to make a Y shaped ridge on fore deck is to realize the "End plate effect" around jib boom area. You know none of our jib boom will stay centered when beating upwind, so you need the ridge to be in line with the boom where it should be. The concave shape should induce more clean air to the lower main sail and minimize vortex generated by cockpit recess.

Patrick
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Old Today, 01:55 AM
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Joined Dec 2014
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Might I suggest a hard turn of the bilge rather than the second immersed chine? The chine adds a small bit of turbulence due to water moving across the hard edge as the boat sails. Eliminating the chine but keeping the bilge turn very hard will keep the stability and hull shape characteristics almost the same while reducing drag.

Just a thought.
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Old Today, 04:48 AM
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Quote:
Originally Posted by Emintaka View Post
Hi Patrick,


Also, I would be interested in your reasoning on going for the double chine. As an aside, I would note that Frank Bethwaite (erstwhile revered and much famed NZ/Australian guru of all matters technical) did some experiments comparing sharp chines to chines with a pencil round. He found the sharp chines gave a 2 per cent advantage, which is considerable in the scheme of things. It seems to me that multi-chines would tend to smooth out this knife-edge effect, cancelling out to some extent the reason for having a chine in the first place. Discuss, please...


n
Hello Emintaka,
As much as I respect the Bethwaites, I am not sure Frank B's findings are applicable here. I suspect he tested on planing hulls such as 18 foot skiffs and 49'er protos? In those conditions, the hard chine does serve to cleanly separate the flow and not have the added drag of flow curling up and around a softer chine.
On a displacement hull, below planing speeds, I think a sharp edge could very well add drag.
Again, I am not a designer, nor have a I made any experiments - but judging from latest designs by BG (Alternative) and IV (V9), they seem to be happy with softer chines.
Just my 1,24 Renminbi;-)
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