THE HAKA BENCH SEAT - AN ALTERNATIVE TO TRAMPS

Good area to mount some starports, for fishing and camera gear then.

Several weeks ago, I sailed on one of Sun-E-Sailor's haka benches. It was a windy day, with 15 knots on our beam. Sitting up on the haka benches, the boat was very well balanced and we sailed 8-12 knots consistently.

Now, I am hooked and wish to acquire a set of hakas for my boat too. But I have no time or talent to build a custom one for myself.

Larry, can you tell us a little more about your stand up paddle boards? Do you believe they can withstand an adult's weight without additional support and braces? Are you concerned with them breaking when the boat rides the waves and the weight is bounced on them?

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Marc K
2010 Hobie Tandem Island
Boynton Beach, FL

[youtube]http://www.youtube.com/watch?v=bfG5qg9OLXw&feature=player_detailpage[/youtube]
Mkrawats the boards are very strong, the video show 15 knot winds two people on the boards. No troubles. They are very nice. I love them and use them all the time. They are "Pelican Flow 104" SUP...

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“Remember life is short- eat dessert first.”
The world is 70% water – So that means we should spend 70% more time sailing than mowing lawns!
Larry

The SUP's look good and have a dual role but they cost about $400 and weigh around 20kg each!
To me, the best off the shelf option seems to be the rotomolded stretcher/spineboards like mbg has. Their negative seems to be cost, well at least here downunder. Being 'medical' adds a huge premium and I haven't seen any less than $300.

Given the popularity of the haka and their benefits to Island sailing I'm surprised Hobie haven't come up with their own rotomolded haka!

I agree with you, Stringy. My initial research showed that the SUP boards can be heavier (50 lbs+) and more expensive ($600+) than the spineboards.

Spineboards are interesting. With Google, I couldn't find the spineboards MBG is using. But I did find other alternatives. They all weigh between 13-16 lbs. They are available for < $200 USD each. Some offer carrying capacity up to 1000 lbs. In my opinion, this is a very reasonable price given the ROI (e.g. comfort and sailing performance) I expect to receive from them.

Rapid Deployment Products carries a nice selection of spineboards
http://rapiddeploymentproducts.com/spineboards

As does Laerdal
http://www.laerdal.com/us/doc/132/BaXstrap-Spineboard

The challenge is to pick WHICH spineboard.

Some spineboards are flat. These flat boards tend to offer decreased carrying capacity and tend to sag more.

Most modern spineboards have custom curvatures along the length of the board. The curvature of the board provides minimal deflection under maximum load. It also increases the patient's comfort when lying down on them. But when sitting on them, curvature can increase or decrease the passenger's comfort. Each board probably has different custom curvatures.

Besides MBG, has anyone else tried a spineboard? If yes, which model?

Do we have any EMTs following this thread? If yes, do you have access to different spineboards to help us compare?

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Marc K
2010 Hobie Tandem Island
Boynton Beach, FL

You're right Marc, not all spineboards are suitable for haka. Back on Page 27 of this thread I tested some that we use at work. The flat plywood boards were useless as they couldn't handle the span of the Islands aka. The curved scoop fibreglass boards could. Unfortunately we don't have any rotomolded plastic boards. A board may be rated at 1000lbs but that would only be if it was evenly supported by 6-8 people using the multiple handholds -not at a span of the 1.5m or so distance between aka.
Mbg reports a 3-4cm deflection using his spineboards. I guess the only way to be sure would be to test the deflection of the board when supported at two points spaced the same as the aka.

A spine board sounds appealing if you can find a suitable pair at a reasonable price.

Personally, I'm going to build a pair of HAKAs similar to those of Captnchaos--see his post above. I was out with him on a recent camping trip and took some pictures. The first is from his post above.


Jim's (aka Captnchaos) construction is straight-forward. This picture shows his HAKA underside. All the boards are ordinary 1x4 pine. He has sanded them, and then painted them with a good marine varnish. He used a good (expensive) marine glue for gluing the cross braces, and then screwed things together with stainless steel wood screws. He also screwed on some rubber pieces to reduce wear on the akas. The shock cord loop is for attaching the HAKA to the aka—just pull the loop and hook it over the end of the HAKA.


This picture shows the aluminum brace. The brace is a piece of trash he picked up on the beach. It is from some type of umbrella structure. This brace adds excellent rigidity to the HAKA.


Finally, I’ve taken a picture the HAKA attached to the aka (see the loop coming up and over the end piece). Jim has a number of points of attachment on his HAKAs which make them more functional.


Jim says these 3-board HAKAs weigh only about 10 lbs. each. I can attest that they are rock solid because he gave me a ride on one. It was a courtesy ride so that I could avoid bushwhacking my way through some thick mangroves. These are Jim’s version 2 of these HAKAs so they illustrate his improvements over the original.

I highly recommend this type of HAKA for cost, weight, and functionality.

Keith

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2015 AI 2, 2014 Tandem

"Any intelligent fool can make things bigger and more complex ... It takes a touch of genius and a lot of courage to move in the opposite direction." A. Einstein

"Less is more" Anon

Here's the new set - 10.7 lbs each (not counting the turtle mascot on one). I just finished the second one. They are teak, like the last set that I made and turned into outdoor benches. You really need a tiller extension when sitting on the haka. By the way, I don't like the amount of force it takes to keep that big sailing rudder where I want it. The cables stretch, too.









I added Hobie leashes to them because I'd hate to lose them if I capsized (not likely and they are bungee'd on anyway).

They are strong enough, but the 3/4" thick ones were really incredibly strong, so I may add some lightweight aluminum L shaped pieces underneath that run lengthwise under the two outboard boards (two on each one). Just to be safe.

Ridin' in style, Kevin ! Mahalo.

We have collected the Ti last week and I have managed to hit the workshop for a couple of days to get started on the hakas.

I have some Ash left over from building a Roubo Bench
http://www.handmadeboxes.co.uk/blog/index.html

just one board so the hakas will be three slats wide


initial planing


and sanding



i wanted to have an overhand to the rear for extra hiking room and was going to reinforce with carbon fibre until I found out how much it would cost and reverted to some 15mm aluminium strips.

These will be laminated in with some epoxy

I have also gone with full length stringers to keep the boards straight and give something to fix on to the akas.


These are made from oak - again what i had lying around in the workshop

There will little or no fixings, just some dominos and glue.

I am working on the design as we go so keep looking in to see how it turns out



more as it happens

CC

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May the odds be ever in your favor..

Back to the workshop on a dreary, overcast Saturday after yesterdays visit to the hospital for an endoscopy and time to put it all together.
Here is the idea for the strengthening ribs



Then cut some slots and holes in the boards for bungees and drainage. The idea here is that modern glue joints are so strong that you are better off having any slots in the middle of the boards rather than between them. Hmmm...we shall see



Using the festool domino just to line everything up with very small dominos



Then we glue up the centre beam using titebond 3. It has fast grab time and is totally waterproof. the fast grab allows us (me) to continue working after an hour of so of clamping. Great when you are a few clamps down!

With the beam sort of dry I routed the slots for the aluminium strengtheners. Again this is non scientific and as the bean seemed pretty strong maybe unnecessary



These are epoxied in using west system epoxy



Then with the aluminium in one side the messy job of putting the rest together again with dominos and eopxy



I elected to set the aluminium below the dominos so it is half in the sandwich adn half out as registering the boards without dominos or biscuits would be a nightmare with slippery epoxy



These will dry overnight for day three,

And just so we are ready i have laminated up a couple of timbers for the ends. Some purple heart which Keith had spare and some mahogany which will make a nice capping piece.



See you all tomorrow!

CC

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May the odds be ever in your favor..

Interesting approach. We are all secretly drooling over your shop setup. ( sigh).

I was going to suggest using the router to channel the boards and trim off some weight. What do you calculate them to weigh?

While you are at it, why not route some side handles/ grab holds for sailing, carrying and hanging?

With your tool setup and techniques, this project would make a good video.

Cheers!
NOHUHU

Thanks for the comments. Yes I think some more holes will be a good idea as they are made from hardwood so fairly heavy. (more scientific weighing to follow)

I am going to fit some leftover scotty mounts for rod holders.



Sunday saw the end caps being glued on. This time with bigger dominos.





It almost looks like the cutouts were put there purposely to allow the end caps to be clamped on!

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May the odds be ever in your favor..

Getting there,..

One thing I should remind folks of - if you use fixed mounting points, such as this, the spacing is usually calibrated for a precise intended location. You may not be able to use it anywhere else. (Closer to the hull, over the tramps, AI vs TI, or say, two benches on one side).



The further you sit away from the hull, the wider the Aka deflection. Thus the angle of any fixed mounting system will need to change. This was particularly true of the PVC half tubes we used on the original Haka models.

CC, what are you planning to put out on the Ama track system?

Good point that and your comments well received.

i have tried to make the location a "sort of curve" rather than "exact" position particularly so it can work with the tramps out and in. To be honest there is a huge amount of "suck it and see" with this. Anyway if it all goes wrong we can have a a few days worth of fire wood!

On that point how has anyone fixed their hakas with the tramp out. is there anywhere to get a cord round it?

I have scotty mounts on the revo and some spare scotty flush mount sockets so was going to fit these to the hakas for fishing rods and possibly for a downrigger in the future.

I will post more about the other mods to the T1 when we get a day sunny enough to photograph them - mostly yakattack gear which I am now importing to the UK I think it is so good!

one more question - i have fitted KB's spray skirts and wanted to run the tension line through a pulley on the aka. Has anyone done this? Just a cord round the bungee button and a harken swivel pulley?

Oh and Nohuhu....you dont have a good ukelele maker near you that you could reccomend? I have just started playing and need a decent uke.... not to mention my Tiki mug collection for which I am always on the lookout for interesting finds.

http://www.ooga-mooga.com/cgi-bin/all/collection.cgi?mode=gallery&user_id=781

we'll be sailing soon.
CC

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May the odds be ever in your favor..