The Raven

Modified Sheldrake Cardboard Core

Start: July 7, 2014.

Finish: n/a

This is the 3rd board I’ve built. 2nd hollow, cardboard core. This is a prototype model; I’m still developing my process.

I use a Sheldrake template and I modified the plans to remove much of the horizontal stringers. On my first board, I just cut them to size or disregarded them, after I had assembled the board. This left the “holes” that the stringers would have filled. It worked OK, but there’s noticeable weakness, bending and separation in places. I removed the slots that the stringers would slide into. I expected to leave stringer near the rail, but it ended up affecting the artistic quality of the board, so I removed them without recutting the pieces (and repainting). I had some issues glassing it and I used too much force testing a mock-up “vaccum bag” using shrink wrap. I’ll modify the plans for future builds. Despite some folks’ intuition, the lengthwise stringers are unnecessary. The board would wobble and be difficult to work with without them, However one (or two, for symmetry) that only connects two cross pieces is enough to lock the whole thing in place. I keep them in the tail area to add a little extra strength for the fins and leash. People hardly notice it. They see diamonds instead of hexagons. This approach gives me greater artistic liberty as well. I edited the drawings using Corel. Unfortunately, I haven’t been able to find a satisfactory way to edit the drawings using free/open-source software. One other benefit to this approach is that the required sheets of cardboard reduce by 7 (to 11 from 19). I had the drawings cut on a laser cutter the engraver at my work uses on cardboard I acquired from the rubbish. I wanted to get the lengthwise rail pieces cut in two single pieces on a cnc at work, but they said it can’t handle such a small bit for the design (they mostly cut relatively simple cabinetry).

My primary goals with this board, beside strength, is transparency. On my first board, I tried to create a highly transparent shell, then adhere that to the core. It didn’t really work too well. On this board, I had an idea to try to use woven roving on the cardboard to get a better bond. There’s a possibility, if done right, this approach could work, but my experience was that the woven roving held it’s (cylindrical) form too well and didn’t seem to want to stick to the cardboard. When I sat the shell on it, the roving stuck strong to the shell and hardly to the cardboard, so I coudln’t really move the shell around to align things. It produced an uglier result than desired, but the board is still blowing minds. On a future board, I plan to skip the roving. I plan to rough sand the cardboard edge, close to 2mm deep. I don’t think the shrink wrap helped much, either. Better to use weight.

Without the lengthwise stringers, until the board is glassed, it is highly flexible along the rocker. In order to work with this, I designed a custom support (out of cardboard) that has a vertical piece every 8cm from front to back. I left some out of the center, which made for a minor flaw. Also, I left the closest vertical piece to the tail 16cm away and 8cm from the nose. This caused some minor sag, but I don’t think it will affect the board’s performance much. Mostly an aesthetic issue. I had the support stay about 6cm away from the rail edge so as not to cause a problem with wrapping the rails. I’ve found a solution to this and I plan to have a vertical piece from from 2cm from the tail and nose then one every 5cm or so. I also plan to build one that will give the proper deck “rocker”, since it stays a little flimsy until 2 pieces of glass are on.

I use foam to give support to the fin and leash plug areas. My first board used 2-part pour marine foam. I had some issues with that, since I had already glassed the board and the pressure from the foam’s expansion caused some deformations. I was able to deal with it, though. On this board, I decided on my fin laout in advance. I chose thruster since it required less foam than a quad layout. That’s mostly because I’m working with a leash plug and even with the plug, I’m only using 2-4 less cells. I think the thruster will be good, because I think it might slow the board down a little. I used the spray foam that’s used to seal gaps you can get at a hardware store. I think the marine pour foam may be cheaper in the long run if you plan to build many, but the spray foam seems to be a good idea for a one-off board. The spray foam is far less dense than the marine foam. It’s water resistant, not -proof.  I took a chance on this, since I don’t plan on keeping it exposed to water for long. Also, I figured it should provide enough support, since I see guys are managing to secure fin plugs to just the cardboard itself. I haven’t rode on it yet, but it seems plenty strong. I took a chisel to it to knock down the resin and it withstood that.

On my first board, I built the vented leash plug in being mindful more of airflow than of strength. I ultimately paid the price for that decision. I ripped the glass around the leashplug on an overhead session and a lot of water got in. I eventually glassed over the plug hole and tried to surf leashless, but there must be a pin hole somewhere I couldn’t find and I gave up on it. The board was pretty heavy, since I used a lot of resin to avoid sanding. It’s now wall art. This board’s primary testing is with the leash plug setup. I ended up reducing the amount of foam I originally planned on, since the probox could fit with 2 of the lengthwise stringers. This caused me to reduce the foam I used around the leash plug. I think my approach this time is much better than last. It seems fairly strong. I’m tempted to get it attached to a machine to actually test how much tension it’s capable of handling, but I’ll just wait to see what happens in the water. This has been the main focus on my R&D on this board. I hope I don’t have to go back to the drawing board. But, I did make this board with this in mind. If it ends up on the wall, at least i’ts beautiful.

On my first board, I used a lot of q-cell to make nice clean rails and painted the rails. I left this unpainted. Only the cardboard core is painted and the areas with foam. It’s not too bad if you have to use a few extra pieces of glass to smooth out the rail areas. It doesn’t need to be as transparent as the center.

A note on the name. I originally thought of a board called The Feather. I may make one in the future, but it lead me to think about making the board a bird, since a bird has feathers. And I thought of a board that I paint different colors so it looks different depending on which way you’re looking at it, so I wanted to try to put some kind of motion into it, so I wanted to create a diving bird. I figured I wouldn’t be able to put much detail into it and would depend mostly on the “pixels” of the cells, which was basically true, so I chose to use the contrasting colors white and black. So I have a black bird. So I started thinking about black birds. I used to have a native american raven logo sticker, so I was thinking about that, then I read a description of the raven as a creature of metamorphosis, and symbolizes change/transformation. Then there was no question what it was to be called.

I can’t wait to ride it and get some footage of it flapping its wings!


moderator’s note: pictures were posted way larger than necessary, which creates problems on some computers viewing the forum.  Here are the links to the pics at the size posted.  

http://www.swaylocks.com/sites/default/files/raven1.jpg 

http://www.swaylocks.com/sites/default/files/raven2b.jpg

I took one, and resized it to 20% with MS Paint.  It went from 2988 x 5312 pixels, to 598 x 1063 pixels.  Please post pics at approx. size they will appear in the post, thanks.

 Amazing work !

Where have you been hiding ?

What’s your history and your background and how the hell did you get so advanced with your techniques ?

Once again…Fantastic work !!

Interesting! Just curious what happens when it gets dinged and takes on water . Is the board ruined? 

When I ripped the leash plug on my first board, it started filling up with water. It was kind of scary, but it only got about 1/3 full of water and still maintained good bouyancy. I think I even caught another wave before I went in. I opened up the area around that ding and put a 2cm hole in the nose to facilitate airflow. It can be difficult to get thoroughly dry. I think you need a high powered shop vac to try to suck out all the moisture and help dry it out. I also ran into difficulty with my first board, because I finished it with bamboo fiberglass, hoping to avoid wax. It didn’t really work as hoped (I had to use some wax) and it was too abrasive. I like to ride shirtless. I can see guys in Jersey with their wetsuits and booties going for it. It does a number on my feet, too. I just used regular plastic fiberglass to maximize transparency this time.

I believe painting the cardboard improves water resistance, but it’s limited because there’s still the inner, wave portion of the cardboard that can still absorb water. I finished the cardboard with a Krylon acrylic clear coat, which is only weather resistant, but I felt it would be good to use. It’d be a lighter application than epoxy, but I very much want to prime the cardboard with epoxy, but I don’t want the weight that I figure goes with it. I plan to build a big wave board with cardboard and I plan to prime that one with epoxy, because I expect it to take some major damage and I need it to be reliable.

I think about adding a screw-cap vent in the nose area. If you’re not just hanging it on the wall, you need to expect to get water in it.

One other thing I changed in the design is the position of the air holes. I centered them, rather than having them staggered at the 1/3 and 2/3 on the verticals. This is mostly an aesthetic reason. The holes are there, which I think help a little. They could possibly be bigger for a functional consideration. Air will still be able to “flow” through the cracks in the joints without the holes, I think. I thought whether they should be on the center or at the edge, where it would connect with the fiberglass. The idea to do it this way would be more for water flow than air flow. It can be difficult to rock the board back and forth to get the water all down to the hole you made in the glass. It can be a bit like playing Pachinko. If those holes were against the glass, I think it would help small streams of water flow, which might be more imortant than airflow? That was one of the ideas I had with just leaving out the lengthwise stringers.

You can stick the board out in the sun (or in your car) to reveal moisture that’s locked in the cardboard as it vaporizes from the heat, then condenses on the glass. It’s at this point I have a hard time getting it fully dry.

Thanks for the kind words. I’ve been surfing for 4 years now. I snow skied for about 20 years before moving to Hawaii. I’ve always wanted to make my own snow skis, but it always escaped me considering the sophistication of their design and the materials. I play bass guitar and I ripped out my frets and filled in the holes with epoxy and fine finished the neck with super glue; that’s the closest thing I’ve done I can think of that’s similar to working on a surfboard. I studied Computer Information Systems in college and I have general interests in geometry and architecture. I plan to build my own house (out of cardboard?). I dabble a bit with origami and so I think that impacts my minimalist ideas. I currently work as a computer support technician for The Art Source. I spent a few years as a quality assurance engineer (boring, but valuable). Otherwise, I’m just a handy man, DYI type of guy.

As far as how I developed my technique so quickly, I mostly had a vision, with clear cut realistic goals. I think a lot. I design up front. I do what I can to think the process through. I actually write down what I plan to do, then think about that and stare at the board or my drawing. My first board was kind of a custom made mini-gun at 214cm. It basically was falling apart on me. I though it was because I was so heavy-footed, but I think it was just that they hadn’t glassed it well, like only 2 4oz sheets on the deck or something. It was cracking under the stress of my turns (big power!) and I was getting a lot of pressure dings. I could see the stringer was obviously strong. The board now looking like: ^. So, I figured, why not make a board out of stringers. Foam is nasty stuff and I don’t see any need for it.

When designing my “stringer board”, I discovered Roy Stewart (olo surfer) and his hollow wood boards and I saw a video of him assembling it and it was such beautiful geometry that he went and covered up! From that point, I was determined to build a transparent surfboard. I was even able to contact Roy and receive his doubt in my success!

I don’t like to preach, but I have to honestly consider that my world-view, as shaped by a Buddhist perspective, may have something to do with my ability to look outside of the box and think creatively.

Here’s where I started: http://www.swaylocks.com/forums/probox-unique-hollow-cardboard-blank

I need to update that and post my second board.

I’m indebted to the swaylock community and I want to let you guys know what you’ve helped create!

But, I’ve been avoiding swaylocks, because I’ve been wanting to work on my boards on my own and get some good surfing in. I’m always busy and I don’t feel like documenting my construction at this point. It feels like too much work. When I have my process down, I plan to document from start to finish.

I did try to take key photos of my progress with this board, but I took my phone surfing a few weeks ago and it didn’t survive. Also, I had scores of film of the whole process of my first board that I lost

I wanted to wait to become active when I could secure a domain for Cellular Surf and so I could start posting under this name. I’m just calling it a project for now and I’m going to put information on my process there and links here and to where I get my supplies. Eventually, I may make boards for commerce, but for now they’re priceless works for me. I have about 15 board designs. I expect to make 1 or 2 a year at the going rate. Stay tuned!

This is the money shot.

You can see the foam in the hole. I drilled 4 holes from the neighbor cells about 6mm. After glassing, I drilled out the hole for the leash plug. I made it a little wider. I like the wall of the hole with a piece of glass and used qcell to keep the epoxy from running. I made the a small “coin” by making a small area of glass with q-celled epoxy and cut it to just small enough to fit into the hole.

I can’t remember exactly what I did with that large piece of cloth. I think I think I ended up cutting it at the center of the long side to help it mold to the walls, but I basically just pressed the coin down into the hole and the coin pushed the glass in. I then put saran wrap over the hold and pushed the saran into the hole with the leash plug and  set a gatorade bottle on it.


moderator’s note: pic posted WAY larger than needed, I resized it to 15% of its original size.  Went from 2988 x 5312 pixels to 449 x 797.  Please resize photos to approx size they will appear in post BEFORE POSTING, thanks!

 

I saw a great video of a guy shaping , then  surfing one of these ,  on facebook …

 

I’ll see if I can find it …

https://www.youtube.com/watch?v=J4Qs7CXYlIs#t=52

so cool! thanks for posting.

embedded video here

I finally finished the board. I’ve been trying to find someone to film me riding, but haven’t been able to. I took it out on Thanksgiving, to Hale’iwa. It worked. Waves were overhead. I was able to subdue my fears of riding on a fragile bubble, even with the signs reminding me of the sharp reef. At first, it felt a little loose and like it wasn’t able to get a good hold, but I was able to rip OK on it. Aired it once and tried a second time, but slipped on the landing as my foot had moved over the rail. 

 

After I got home, I noticed some water accumulating on the rail (I hang it horizontally on my wall), toward the back of the board. Upon trying to get the water all in one place, it appears to have absorbed into the foam surrounding the find plugs, as well as into the cardboard. The cardboard around the fins is a little noticealby soft. I’m likly to surf on it in this condition.

I’m not sure where the hole is. I’m confident it’s on the back half of the board. I’m curious if the gortex vented leash plug is leaky. I’m thinking about dropping the rear of the board into a water-filled ice chest. I can kind of flex the board and push to make it “breath” and hopefully produce some bubbles.

So I have this problem of dealing with water getting inside. I can’t jump to any conclusions until I find the hole, but I’m starting to work on my next board, which I’m just focusing on functionality. I believe these hollow boards require a vent for air, because pressure builds with temperature fluctuations. 

Good chance the leash plug is leaky: http://www.swaylocks.com/forums/help-leaking-vented-leash-plug

So the vented leash plug might not be such a great idea after all (it’s a great idea, not perfected), esp. not short board. I might have to make my own vents or put one a the tip of the nose and consciously keep my nose above water. As recommended for this plug, whose maker indicates it may leak, esp if kept submerged.

So, I think until the gortex filter is perfected, I’m going to have to work under the assumption that these boards will get water in them (upon the inevitable ding). Accordingly, I will:

  • "prime" the cardboard core pieces with epoxy. 
  • have a screw vent that allows water to be released. This would be placed far to the front of the tip, but inside the rail pieces.
  • Use waterproof marine foam or no foam. If using foam, want to seal the area so water cant get into it at all, unless that area is damaged. I aspire to eliminate foam.
  • I will be modifying the design so that the "air holes" become "water holes" and they will align to the deck, so I can tip the board upside down and the water should flow fairly smoothly. I will also add holes to the rail pieces to help facilitate the movement of water.
  • It seems desireable to have a vent at each end of the board to help facilitate drying. A second vent may be unnecessary with the priming of the cardboard with epoxy and having a dedicated screw vent for releasing water. I would place the second vent at the tail, to the side of the (unvented) leash plug.
  • Use a standard leash plug.

I’ll be thinking about retrofitting a screw plug onto this board to help the water out, in the mean time.


Very nice looking board.  I’ve made several hollow boards, and yes, they need to be vented.  Unless maybe a chambered board, but anything with a thin shell over a frame will need venting, the expansion / contraction of the air inside is too great to be contained by the shell.  I’ve heard stories / seen pictures of hollow boards “blowing up” when left in the sun unvented.

For this reason, I’ve pretty well stopped making hollow boards, and gone to foam.  All my hollow boards ended up being “fragile” because of the constant need to check the vent, is it tight in the water, is it open on land, a tiny pinhole will “suck” water in due to the air contracting in the colder temp while surfing, then have to dry everything, try to find the leak, etc.

I’d like to return to making wood boards, this time combined with foam.  Not in the standard “compsand” way, 'tho - anyway, a subject for a different thread.

This one was covered with model airplane tissue before glassing - I intended to surf it, but somebody offered me a pretty penny for it to hang on their wall before I got the chance.  Probaby wouldn’t have been very sturdy anyway, its better off as a wall-hanger.

That board looks familiar. I think I’ve seen it in my vent researches. Thanks for your contributions!

I’m thinking of it in a chambered sense. It’ll be easiest to prime the cardboard before it’s assembled. I may go through the trouble of sealing the joints after construction. I probably should to really make it work as intended. I might skip the joint sealing on a shortboard. I’ll definitely be sealing the joints in my big wave board.

I’m pretty determined to get a good working solution for these hollow boards. I have a couple of designs that call for electronics. I never want to touch foam again if I can avoid it. (I ask for $5,000 minimum from anyone who asks me to shape them a foam board).

In the image, you can see the left side is the original cuts for the core. As seen on the right, I’m moving the “air holes” to the top and removing them from the bottom. The joints on the bottom of piece 15 will need to be sealed. The ide being that if a ding occurs within one of the cells, then I can expect that cell to fill up with water. if it actually fills up completely, it will start to spill into neighboring cells and there’d be a kind of exponentially less chance of water migrating beyond the damaged cell(s). But, the holes would facilitate the removal of the water. Also, you can see on the rail piece 74, I’m planning to add holes on the rail edge to help water flow, because water is tending to migrate to the rails and getting stuck in the gaps.

 

Well, I hope you do find a good working solution for hollow boards.  

The vent was always an achilles heel in my book, I never found a vent that was completely satisfactory.  The goretex vents sometimes fail, and come with a warning to replace every few years.  And they sometimes work, but fail to work quickly enough - so that it is then recommended to install multiple vents.  

The screw type vents don’t always seem to be 100% waterproof, and then there is the factor of human error - forgetting to tighten before surfing, or forgetting to remove after surfing.  

And small dings are also far more serious in a hollow board than a foam board - since they also allow for water intrusion, and then an involved process of removing the water and thoroughly drying out begins, often involving pumping air for a time through the hollow structure.  And the certainty of water intrusion at some time necessitates making the board waterproof inside as well as out, adding weight.  The board I posted was sealed inside, but only perfunctorily - meaning it wasn’t really waterproof, just water resistant.

Don’t know the reason for your aversion to foam, but environmentally I always felt a well designed and well built foam board that is kept and utilized for years makes a smaller footprint than a board built with environmentally friendly materials (and covered with standard eco-unfriendly materials), that dies young from water intrusion, or is shelved for sub-par performance.

Still, I applaud your determination, not an easy path these boards that you have chosen, looking forward to following you on your quest, thanks for posting!