Pickled Fish

General Discussion
1

I think I’ve been in the sun too long!!

Having mulled most of the summer on three ideas that are somewhere out there where the air is rare, I have shoehorned them all into one design.

Let’s begin at the beginning, a very good place to begin. (Julie Andrews moment)

I’ve had an old longboard up in the shed rafters for over a year, semi stripped; and have wanted to knock a fish out of it for a while. I took the Stev Lis 5’ 5" fish plans and stretched it to 6’ 6" (my regular shortboard is 7’ 4"). It was gonna be so trad an’ all; but then I was seduced by those aforementioned ideas.

Firstly, I was seduced by Steve Morgan’s long channelled Converter,

http://www.hicconverter.com/

Always been a fan of hard channels

Then, I was tickled by the polarised views, expressed here, about Jeff Alexander’s Pickleforks,

http://www.alexandersurfboards.com/gemini_physics.html

I reasoned that I was happy to ride chisel/snub nosed boards (often 6" wide snubs) and reap the benefits of more parallel forward rails, so it was only a short journey down ridicule street to a picklenose.

Finally, someone posted up this pic of a board by Randy Walker of Pearson Surfboards, Santa Cruz

http://www.ksusa.org/Forum/album_pic.php?pic_id=1991

I became fixated with the idea of the keel fins becoming an extension of the hard channels.

So, the ideas festered in the back of my mind until they burst forth as this god-awful thing

(see attachment).

It’s 6’ 06", 18x22.5x19, 2.75 thick.

Comments please… bring me to my senses!

Roll-mop herring anyone?

800×556 24.2 KB

2

IMHO the concave channel should be wide at the entrance and narrower at the exaust, like the HIC. This will generate lift. The timeglass concave channel on the diagram will generate lift in the nose, but possibly sucktion in the tail(drag). IMHO you should have a channel where the deep part of the channel is almost a straight line, and the channel should only narrow slightly toward the exaust to get minimum drag.

Besides that, it looks sound and (in)sane. Go for it!

regards,

Håvard

3

I like it too, for deep dark reasons that shall remain nameless…You may have problems with those fins biting, though, they don’t go very deep into the water, and would probably spin out easily, especially riding over aerated or swirly water…I would go no longer than six-foot, though, if it’s flat and wide, you won’t need the length…

4
Quote:

IMHO the concave channel should be wide at the entrance and narrower at the exaust,

like the HIC.

Is that the HIC Converter you are talking about?

Because that has a channel that is narrow and deep at the nose, and wide and shallow at the tail (with a bonzer-type exhaust).

This will generate lift. The timeglass concave channel on the diagram will generate

lift in the nose, but possibly sucktion in the tail(drag).

Do you think that would still be the case if the foreward end was deep and the aft end shallow?

(the volume of the venturi thereby being equal along its length, and therefore not a venturi at all)

IMHO you should have a channel where the deep part of the channel is almost a straight line,

and the channel should only narrow slightly toward the exaust to get minimum drag.

I must admit I am struggling to marry a number of parts of this design.

I am keen to retain the six keel fins integrated into the walls of the six channels. But I am struggling to combine that with the deep/narrow to wide/shallow full length channel of the Converter (and Gemini). I agree, the long channel would be better with a straight edge (I’m not sure about the parallel thing): but if I were to do that the vee-panels on each side would be a lot smaller.

Besides that, it looks sound and (in)sane. Go for it!

Thanks for the encouragement.

5

Interesting that you mention Alexander’s gemini… a friend of mine just came back from Fiji (did I spell that correctly? It looks odd), and said he was blown away by two guys riding Geminis in very critical waves… he described them as blowing everyone else out of the water in critical overhead-DOH barrels.

6

Well in that case, everyone should just get Gemini boards to improve their surfing, since we know it’s the surfboard, not the surfer, that rips in the surf.

And we all know it’s most important to have a twin nose, because it is just so superior to all other designs.

7
Quote:

Well in that case, everyone should just get Gemini boards to improve their surfing, since we know it’s the surfboard, not the surfer, that rips in the surf.

And we all know it’s most important to have a twin nose, because it is just so superior to all other designs.

Meeaoww… Lee! Have some milk.

I accept that the pickle nose is just an affectation, and that a snub nose of the same width would be just as effective; we’ve thoroughly stomped that divot a while back. Where the Gemini gets an advantage it is through having a wide nose(s) area, more parallel rails up front and that interesting deep channel.

It is the ‘interesting deep channel’ (shared by the Converter design), that I would really appreciate some advice on.

8
Quote:

I like it too, for deep dark reasons that shall remain nameless…You may have problems with those fins biting, though, they don’t go very deep into the water, and would probably spin out easily, especially riding over aerated or swirly water…I would go no longer than six-foot, though, if it’s flat and wide, you won’t need the length…

Yes I am too afflicted by a dark perversion for this board. :wink:

The fins on the original were an attempt to by beat the dreaded kelp beds, see;

http://www.ksusa.org/Forum/album_showpage.php?full=&pic_id=1991 I might be tempted to go with deeper keels, but with six fins I don’t want to make it too stiff.

As this board will be a kind of test bed, I might go with bigger keels and grind 'em smaller if necessary.

As to the length. I am a fat and lazy 95Kg (210lb), ride a 10’08" crowd beater (18x24x14.75", 4"thick with full rails and low rocker) most of the time and a 7’04" shortboard (16x24x15", 3.25"thick with 6 hard channels) when the crowds/waves permit. I think a 6’06" fish is as small as I want to go this time, but I have another beatup longboard I can hack down if I like this one.

Thanks for all the comments.

9

Jesus Lee, thanks for mincing my words/intended message.

The point I was making was a friend of mine was very impressed at the skill these guys demonstrated on alternative equipment. When he first saw them paddle out, he thought there would be no way that they would be able to hold into the throating barrels on their small, wide, wierd boards with oddly-placed fins, and considered himself corrected and impressed within 5 minutes

I am well aware of the flak Alexander et al have taken for their wierd boards, but the fact is that the boards do indeed appear to work… as do modern thrusters, fishes, singlefins, etc etc etc. The double-nose thing is probably aesthetic, and not in a make-it-prettier manner, but they demonstrated that riding one does not make or qualify one as a kook.

10

Hmmm, the hic converter website has changed alot since last time I checked it. I swear the channel was wider at the front then the tail when I last checked it :-p Anyways, the channels should hold more volume of water in the entry and go to less volume to generate lift. If you look at catamaran personel ferries or the offshore racing boats (http://www.hydrolift.no/bilder/glommafestivalen04/2a.jpg have some similarities to your board design) you will find this design. The entry is much wider and higher than the exaust. IMHO the channel should not have any abrubt changes in it’s lines to maximize lift and maintain a minimum drag. Bdw. I don’t think you can have the same ratio to the entrance/axaust as with the boats since you don’t have an engine. Also the FP plans may be of use, but again, I think the change ratio from entrance to exaust is IMHO to extreme.

regards,

Håvard

11

http://www.class-1.com/ for the insane offshore raceboats.

regards,

Håvard

12

Cool ideas and drawings.

Twin pointed noses seem like double the hazard. Square or rounded will keep the width.

The full-length and deep channel looks slick. I’m a little concerned how water moving sideways or at an angle (as when surfing rather than paddling) will react in the front half of the board. Anyone know?

The six fin set-up can work if the first set is deeper.

13
Quote:

Hmmm, the hic converter website has changed alot since last time I checked it. I swear the channel was wider at the front then the tail when I last checked it :-p Anyways, the channels should hold more volume of water in the entry and go to less volume to generate lift. If you look at catamaran personel ferries or the offshore racing boats (http://www.hydrolift.no/bilder/glommafestivalen04/2a.jpg have some similarities to your board design) you will find this design. The entry is much wider and higher than the exaust. IMHO the channel should not have any abrubt changes in it’s lines to maximize lift and maintain a minimum drag. Bdw. I don’t think you can have the same ratio to the entrance/axaust as with the boats since you don’t have an engine. Also the FP plans may be of use, but again, I think the change ratio from entrance to exaust is IMHO to extreme.

My full length channel will be deep at the front and shallow at the rear; this, combined with the increasing vee in the channel base as you aproach the tail, will mean that the cross-sectional area of the channel will decrease from fore to aft, despite the widening of the channel. In a way it is misleading to invoke the venturi effect for open channels; as that pertains to closed tubes.

It is interesting to note that in open channels, where the fluid flows over the restriction as well as in it, the greatest pressure and speed is not at the throat of the restiction; but at a point some distance beyond. See the article about gap winds at;

http://www.weathernotebook.org/transcripts/2004/07/30.php or,

http://www.suite101.com/print_article.cfm/13646/107207

I have noted your concerns about the curvy track of the channel wall and have reduced the hourglass effect (see attachment). I could have had a straight track from the front noses to the rear fins on the tip of the fishtail, but i thought that would reduce the side vee panels too much.

Another possibility is to divorce the full length channel from the fin/channel combos; but I am loath to do that, preferring the integrated approach.

800×303 4.62 KB

14
Quote:

Cool ideas and drawings.

Thank you (all stolen mind) :wink:

Twin pointed noses seem like double the hazard. Square or rounded will keep the width.

Pretty blunt hazards compared to the Geminis (but will fix nose guards). I will try that experiment that someone suggested, of sticking duct tape across the nose crack to see if it affects things. I might try it with the fish tail too.

The full-length and deep channel looks slick. I’m a little concerned how water moving sideways or at an angle (as when surfing rather than paddling) will react in the front half of the board. Anyone know?

The Converter website says,

“The channel walls, known as the track, act as secondary rails creating more forward drive as well as giving the board added traction in critical situations”,

and,

“In the case of nose riding on a longboard, it is natural for the board to want to sideslip, however, with the aid of the track, the board will stay its course. In the case of a shortboard, this track helps to increase momentum by stabilising the board, and by nature of the design, allows the surfer to ride higher on the water’s surface. The beauty of this secondary rail is there is no hangup; it can be easily released and does not interfere with the normal turning aspect of the board.”

(that’s enough bovine waste for anyone)

The six fin set-up can work if the first set is deeper.

I can see the fins will be an ongoing project. It’s a shame I won’t be able to use a fin system (cos the fins need to be completely flush with the channel walls).

15

I LOVE IT!! A good starting point for something completely different. Keep up the chatter I’d like to see this type of board developed further…

Hicksy

16

Interesting articles. I think since water is more solid than air and don’t compress you would get more of the venturi effect and less of the gap effect than if we were talking airgoing through the same channels.

One thing tho’, with so many different designs in a board it will be hard to tell what does what. But then again, I guess you don’t have the time nor the funds to test all the different designs by themselves before combining(I certainly don’t)

regards,

Håvard

17
Quote:

Interesting articles. I think since water is more solid than air and don’t compress you would get more of the venturi effect and less of the gap effect than if we were talking airgoing through the same channels.

Not sure I agree with you on that one. Although water is described as a, virtually, incompressible fluid; that doesn’t mean it doesn’t vary in pressure from one spot to another. As water travels down a venturi channel the pressure in the channel will increase as it apporaches the neck. There will be a point where the pressure within the walls of the channel is higher than the water outside; the higher pressure water will travel to the area of lower pressure and spill out of the channel.

One thing tho’, with so many different designs in a board it will be hard to tell what does what. But then again, I guess you don’t have the time nor the funds to test all the different designs by themselves before combining(I certainly don’t)

Indeed, it is rather a well-mashed stew of ideas!

Frankly though, many of the concepts here will have little effect.

I don’t expect I will be brave enough to make the full length channel deep enough to significantly affect flow (I don’t want it to paddle like a brick).

The fish shape is pretty much a proven design, so that should throw up too many suprises.

The pickle nose, I believe, is just a silly affectation (but kinda fun).

I reckon the biggest potential area of interest will be the fin/channel combo. To this end, I have resolved to shoehorn a fin system in there somehow ( it would resolve the problem of filleting a fin that sits right on the edge of a channel). I thought I could layup the bottom, with the fin channels as nornal; rout out the holes for the fin plugs right down through the channel walls, so that when the fin is in place, the inside face is flush with the channel walls. I would also have to cut back the channel wall to accomodate the foil thickness of the fins. Then I would backfill the gap made when routing the slots for the fin plugs (I feel an explanatory diagram coming on).

18
Quote:
Quote:

Interesting articles. I think since water is more solid than air and don’t compress you would get more of the venturi effect and less of the gap effect than if we were talking airgoing through the same channels.

Not sure I agree with you on that one. Although water is described as a, virtually, incompressible fluid; that doesn’t mean it doesn’t vary in pressure from one spot to another. As water travels down a venturi channel the pressure in the channel will increase as it apporaches the neck. There will be a point where the pressure within the walls of the channel is higher than the water outside; the higher pressure water will travel to the area of lower pressure and spill out of the channel.

With water it will take a longer time for the water to redirect when it hits an obstacle which result in more pressure and possibly less deflection which IMHO is what causes max gap wind to happen further from the gap. It might depend alot on the scale tho, and I might be just plain wrong. :slight_smile:

Good luck, hope you can figure out a way to fit some fin system plugs to tune it.

regards,

Håvard

19

Well here’s the reality (see attached pics).

High Concept… low skills… terrible paint job!

Will keep you posted when I get it in the water.

Quote:

I’ve had an old longboard up in the shed rafters for over a year, semi stripped; and have wanted to knock a fish out of it for a while. I took the Stev Lis 5’ 5" fish plans and stretched it to 6’ 6" (my regular shortboard is 7’ 4"). It was gonna be so trad an’ all; but then I was seduced by those aforementioned ideas.

Firstly, I was seduced by Steve Morgan’s long channelled Converter,

http://www.hicconverter.com/

Always been a fan of hard channels

Then, I was tickled by the polarised views, expressed here, about Jeff Alexander’s Pickleforks,

http://www.alexandersurfboards.com/gemini_physics.html

I reasoned that I was happy to ride chisel/snub nosed boards (often 6" wide snubs) and reap the benefits of more parallel forward rails, so it was only a short journey down ridicule street to a picklenose.

Finally, someone posted up this pic of a board by Randy Walker of Pearson Surfboards, Santa Cruz

http://www.ksusa.org/Forum/album_pic.php?pic_id=1991

I became fixated with the idea of the keel fins becoming an extension of the hard channels.

So, the ideas festered in the back of my mind until they burst forth as this god-awful thing

(see attachment).

It’s 6’ 06", 18x22.5x19, 2.75 thick.

Comments please… bring me to my senses!

Roll-mop herring anyone?

20

Another photo