Tri Fold Surfboard Design

General Discussion
1

Hi all, First time swaylocks post, Long time swaylocks lurker.

Im building a tri-fold board for the exploitation of lax carry on luggage standards on budget carriers for cheap short long weekends abroad surfing. I have settled on a board shape that i thought would be perfect for the job and banged it out on board CAD. I have one of Berts boards (top and bottom balsa skin with balsa rails) and i absolutely love it to death, the problem is finding a way to make it die. So i decided to make a vac bagged compsand. I choose 0.6mm bamboo veneer for the skins,The rails are gonna be made from 4 inch wide carbon tape to maintain the rocker with the bagging as i dont have much kit (Aussie in England temporarily) to be fooling about with rocker tables and the like.

Below is a crappy ms paint diagram of what i want to do, below that a step by step of what i understand would be the best (and least amount of equipment) way to do it with the questions beside them.

Steps

1.Im going to use the spare bamboo sheeting to make the blocks where the three pieces join, Im thinking of cutting the blank into four pieces (tail included) fitting the shaped blocks in (What adhesive would i use to stick the bamboo blocks to the foam?) fitting the pvc piping to route the cables in and then glueing the blank back together to be laminated.

2.Following what Thirdshade (a big up to Richard for getting me on track) did for his carbon rails (http://www.swaylocks.com/forums/first-time-vac-bagging-build) except dont do a cut lap as the bamboo skin covers it up (is this a correct assumption?). **Should i seal the rails with microballoon/epoxy before or just wet it out when the carbon is stretched out? I have observed mulitiple methods on this one. **Depending on how dense the weave of the carbon tape when i recieve it will make me decide if i will paint black underneath do to the white showing through problem.

3.Following the WMD videos lay 4oz on the bamboo and laminate the deck skin.Laminating 1.5oz on the bottom also. When dry cut to size .

4.What does Greg Loehr use to stick the Bamboo/4oz  to the unsealed deck? Why no spackle or seal on the EPS? What pressure should i use to pull the vaccuum? I have found mention of 7 psi up to 15 psi.

5.Free lap 4oz on the bottom and around the rails, then laminate the top.

6.When the lamination is finished (rails,skins and glass over the top) will route the cavities for the fins (this is a quad) and the leash plug and fit them in.

7.Chop the board into three and put some 4 oz glass over the
top of the raw bamboo ends plus do all the countersinking for the m6 bolts as
well as fit the three goretex valves in. Then stick thin rubber matting on the ends.

Does this sound like the right order of things? If not please make suggestion on where i could potentially go wrong.

Thanks in advance

JD

 

 

 

 

2

hi, i like your ideas. the vid in the link shows it can work , good luck ,

ps where do you live ,  pete

 

http://www.youtube.com/watch?v=s4ZYchaf7eI

3

Have you read the other travel board threads on here? I think the wire will cause problems. There was a good one useing cut finboxs probox maybe? The strength is all in the skins so makes sense to join the sections there.

4

That’s a lot of work. I think that the obvious drawback is that you’ll be compensating performance since the board is cut into thirds. That alone will throw the performance way out of whack for a short board. Why not just support a local shaper and rent or buy a used board?

5

So you'll be able to put a shortboard in you carry-on??  So what goes with all the stuff that normally would go in your carry-on?

6

@fiberglassi

I have compensated for the extra weight with extra volume. I am often far away from a “hire” place (local willing to lend his only board), plus the time lining up a board and so on doesnt lend itself to spontaneous random surfs. Any contributions to the questions posed? “Thats a lot of work”…i have plenty of time.

@Mcding

I travel very light so it is possible. These are long weekend trips.

7

Yeah I have, I have worked with cable structurally and I think if done right it is a superior method as compared to the batton/clip for joining the sections.

8

This is an interesting design challenge.  I believe I will subscribe.

My first thoughts are perhaps your cables could be combined with a telescoping carbon tube system (tube system similar but not identical to handles for luggage).

9

It’s an interesting concept,  definately a more flexible design than the typical  carbon batton tube and clip method you refer to.

Unless you tension quite high each break section might just act like a hinge in each locations. Like one of those wire hinged wooden snakes I played with as a kid…

I’m wondering what kind of tension you’d have to place on the cables to result in a  somewhat natural flex pattern?

I’d build some test sample sections first to see what deformation the tensioning of the wire places on your bamboo end caps.

Have fun anyway.    It’s always nice to read posts from people thinking outside the box.

VH.

10

Hi Jd
Been thinking this one over - is there any way you could use a sort of hinge at the bottom - wouldnt actually have to be a fixed hinge - could just slot together - that way all the compressive load down through the deck will act to close the hinge tightly together - the wire could then be simply used to resist the hing opening - if it were placed close to the deck than the bottom where the hinges were you would have a mechanical advantage in the structure.
Cheers
Rich
www.thirdshade.com

11

I think inter-locking joints that are pressure stabilized is the approach needed.

A concept like the Lego building block toy for children might work as pressure stabilized joint.

http://upload.wikimedia.org/wikipedia/commons/thumb/3/32/Lego_Color_Bricks.jpg/800px-Lego_Color_Bricks.jpg

12

I drew this up at the start of the build to address the hinge problem, is this what you were getting at Thirdshade? Ignore the bad out of proportion feet!:slight_smile: I made some generalisations mainly the water normal force is uniform across the surface area of the board. My plan is to add “keys” or as stonerburner would put it lego strips attached to the skins to minimise hinging. Any further ideas??

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Im going to lay rubber matting over the ends to preloaded the cable (like a washer), any ideas what would be the best product for the job?

13

Im an Aussie temporarily living in Leeds UK. The difference between my  design and Waldens is the wire orientation, i figure that a surfer is alternating the transfer of force through the balls and heel of the foot so i thought to run the wire through there. Unfortunetly this method sets more of a pivot point then Waldens so i aim to combat that with interlocking joints.

14

hi, i live in cornwall and have a vac pump and adjustable rocker table  if you were closer . leeds is pretty far away but the offer is there if you want to combine a surf trip with a bulld session ,  i think rich/s (thirdshade) method  is  a valid way to set rocker enough to vac down glass or skins without a rocker table , 

it also depends on what you are useing for a blank , insulation foam at 1 lb , like whats inside you burt board would yield a good weight but i would think it would be a nightmare to fully keep everything water tight  and each section of the board would need to be vented to prevent expansion ,

xps from knauf is available from sheffield insulation  1.9 lb and totally water proof but really needs to be set with a rocker table, 

marko  eps foam from seabase is probabally easiest allround , 

i would think you could use some dowels to suport the face joints easily , pete

15

hi, i live in cornwall and have a vac pump and adjustable rocker table  if you were closer . leeds is pretty far away but the offer is there if you want to combine a surf trip with a bulld session ,  i think rich/s (thirdshade) method  is  a valid way to set rocker enough to vac down glass or skins without a rocker table , 

it also depends on what you are useing for a blank , insulation foam at 1 lb , like whats inside you burt board would yield a good weight but i would think it would be a nightmare to fully keep everything water tight  and each section of the board would need to be vented to prevent expansion ,

xps from knauf is available from sheffield insulation  1.9 lb and totally water proof but really needs to be set with a rocker table, 

marko  eps foam from seabase is probabally easiest allround , 

i would think you could use some dowels to suport the face joints easily , pete

16

hi, i live in cornwall and have a vac pump and adjustable rocker table  if you were closer . leeds is pretty far away but the offer is there if you want to combine a surf trip with a bulld session ,  i think rich/s (thirdshade) method  is  a valid way to set rocker enough to vac down glass or skins without a rocker table , 

it also depends on what you are useing for a blank , insulation foam at 1 lb , like whats inside you burt board would yield a good weight but i would think it would be a nightmare to fully keep everything water tight  and each section of the board would need to be vented to prevent expansion ,

xps from knauf is available from sheffield insulation  1.9 lb and totally water proof but really needs to be set with a rocker table, 

marko  eps foam from seabase is probabally easiest allround , 

i would think you could use some dowels to suport the face joints easily , pete

17

As the only interlock, small diameter dowels may focus a large amount pressure on small areas of foam.

Hinges are likely to place large pressure stresses at a few focused points also.

Each segment of the board will act as a lever.

 

18

The “Lego” interlock concept I mentioned would place the interlocks between each segment (in the joint) primarily.

19

Thanks so much for the offer, i cant travel down for the build of this board as ive got alot on my plate up here. I’m using homeblown blanks (which i believe are close to 2.5# foam), i know how much of a noodle the foam in BB’s boards are. Im venting through Goretex vents in the leash cup and on each of the sections. I think i might use open half sections of aluminium or Stainless to interlink the deck pieces.

Oh BTW nice triple post pete :wink:

20

Some inspiration for you:

http://www.swaylocks.com/forums/another-two-part-not-bisect-tm-travel-compsand

http://www.swaylocks.com/forums/el-cockos-centerfold-collapsible-surfboard

Scroll almost all the way to the bottom on this one:

http://surfingsports.com/labels/Imagine%20surfboards.asp

 

I realize none of these are close to your wire method, but same concepts apply as far as loads and join methods. More just to show that it can be done and give you some references to how others have approached the problem.

Won’t 2 sections be enough to fit most airline requirements? That might simplify things a bit.