oh yeah almost forgot, thats some nutty stuff in the background huh?
There sure is! I love the Image Zoom extention for Firefox. I always find myself zooming in on peoples boards to see what I’m missing. Did you notice that there appears to be a double horizontal stringer.
I agree with what you said about your short board. They have to be built differently from the longboards.
“the day just before he saw the light…plan B…dangle a carrot on the net and they’ll come…worked like a charm”
also helps get a few problems solved from other peoples perspective and experiances
“So the rails get 4” glass tape or something, to connect the outside of the top & bottom skins, but the insides aren’t connected by any glass. "
Benny, help me understand this better, please. thx
After playing around with a few methods, here’s what I’ve come up with:
*Be inaccurate (don’t worry about getting the pieces to butt up perfectly, small gaps are fine)
*Make sure the pieces are smaller (just slightly) than the rail profile itself (helps a ton when taping and/or bagging to not have anything extending past the deck or the bottom)
*Don’t try to do everything in one pass (though if you come up with a good method, PLEASE TELL ME!)
*Don’t use anything over 3/16" thick except for maybe one or two of the panels in the center of the board
*Keep each panel fairly short (1’ to 1.5’ worked great for me)
Here’s the process that I found worked best for me (having an extra set of hands helps a bunch)
Cut out the outline of the blank, but don’t skin it yet
Trace the rail profile onto a fairly thick (the thickness helps later on when you’re tracing) sheet of paper
Cut out the profile, making sure to cut just inside of the the line (you want to aim for pieces that are roughly 1/16" (perfect) - 1/8" (getting worse) smaller than the rail itself)
Roughly layout your pieces of balsa so that they match up with the profile (this will require angling the ends of a few of the pieces, but as long as you keep the pieces fairly short you should only need to do this with the ones near the end)
Trace the profile onto the balsa using a sharpie (you’ll easily plane off the pen marks later on)
Use a roller cutter (the one’s made for fabric) to cut out the panels
Attach the pieces to the rail, one at a time using wood glue (held up just fine) and the cheapest tape you can find (one roll of $0.45 3/4" tape did the job for me) working from one end to the other
Repeat steps 4-7 as many times as needed to get the thickness you want. Don’t worry about the glue still being wet on the previous layer, just lift the tape, put down the new piece, and tape again (many times you can actually reuse the tape that was holding the previous layer on)
Do the same on the other rail
Retape the outer layer with as much force as you can get out of your tape (or put the whole thing in the vac bag if you’re the ambitious type)
Hope this helps. If anyone has a way to improve (and by improve I mean quicken) any of the steps above, let’s hear it! I’d love to be able to just drop my blank off somewhere, say ‘Make em 3/4 of an inch please’ and then pick it up the next morning. But until then, I’m happy with anything that speeds up the process in any way.
Ben
You tried this yet?
I guess it works best if you hot wire the rocker profile first then cut your outline offsets.
Building with sheets is a litle more difficult but maybe not is I set the rocker as squared halfsheet taped to my model.
Using your guess on Bert’s technique
is he building out the skins on a flat surface or a rocker table?
Seems like with a bunch of sheets of cheapo plexiglass you could build out a bunch of these all at once, glass then resin then wood then peelply then absorbant then plexi then repeat. On a flat surface this would be easy to do if you had the time(system3 resin with slow hardener?). Just crank the vac pressure up to 20-25 lbs and maybe do this in a plywood hot box as a cheap autoclave. I could see doing these out of those 4’x8’ bamboo lattice sheets cut in half.
I really really like the idea of prefabricated skins…
Makes sandwich board building more production like.
If you combine that with your perimeter stringer / solid rail technique and alter the materials in the rail build out I think you can get away with managing the flex without doing a thick piece by piece custom rail build out you say Bert’s doing. For instance alternating the strip build out with different woods for different effects as you build out your planks to cut your solid rails out of.
I just built a 6’8" shortboard using 13"x1/8"x100" thick maple down the middle of the deck wrapped around the nose and tail. The stuffs incredilble… When I unwrapped it from the shipping box it refused to unbow (no matter how much softener and hollowtiles I put on it) maintaining the huge arc like a giant spring shape you’d see in wood skate decks or ski’s. Infact it’s specifically sold to make laminated skateboard decks… I used the natural arc as my opposite curve deck springer attaching it to the nose and tail with our standard vac rail wrap on the nose and tail for effect. Just another experiment…Nice tough deck patch right down the middle though…
I also got this stuff in 1/8"x8"x24" long strips which could be strategically joined with 1/8" thick balsa stips to stiffen out certain parts of the rail bands in place of a single deck strip running nose to tail. Combine that with your 1/16" thick prefab balsa skins and it becomes a leggo set. If you use 1lb EPS sheets and insert an internal springer like a 4" wide horizontal maple strip like DanB shows( nice pic catch DanB) you can really do some testing cause the final build is so easy.
I guess it’s like fine cooking everything is in the prep…
But of course you still need a proper shape…
I think that the piece where we’re missing it. Bert’s beyond materials and more into shape I think that’s the missing piece in Bert’s message.
Meecrafty is the only one looking at it this way… Changing the rocker profile, thickness beyond what we’d do for a “normal” design. At least you gave it a go with Mr’s Peanut…
Mr.J did it and CarveNalu but I don’t anyone giving assymetrical much of a thought either… I guess everyone can switch stance pretty reguarly.
It’s pretty hillarious in that we always seem to want to advance performance while keeping it symmetrically pretty and “design-comfortable” at the same time. The challenge will be to understand why we are so afraid of riding something that might be termed “ugly” in the lineup…
Once we all can get past that then I think some real advancement will occur…
cool stuff …
you guys are progressing beyond belief …
oneula , youll have to make an introduction and give me the run down on your day job , i have a feeling youve been talking to some of the same people i mix with …
ive been lost in space lately , after the move across the country from west to east , all our stuff was missing in transit …
it was supposed to arrive a few days after we flew in , but instead took almost 6 weeks to land , so in that time , i had no office and no communication with the outside world except webmail , and that is just a total rip off and nothing but pure frustration to lose every second email into cyberspace …
just to clarify a few things , i see a few valid concepts being thrown around , and they are all valid , but need to be weighed against shape …
if our shape promotes extra flex , then we need to look at a stiffener , but a stiffener that still alows flex , so we can take advantage of the springback …
plus also take into consideration the riders weight …
one of my best team guys is 85 kg , im 100 , my board needs the ability to spring back hard against my weight , when my 85 kg team guy rides my board , he reckons he cant load it far enough to get the desired launch , but when i ride his board it starts to fold to early and effect my timing out of the turn …
controlling flex in the skins is a valid option , but can have the effect of creating to much stiffness in the overall structure , thats where shape comes back into it again …
there are a number of formulas that work …
as far as technique for applying rails , it can be done in 10 minutes , or a full day , depending on how much you want to spend on your preparation tools and work area …
the other day i was weighing up the odds , i was offered a machine that was going to cost 97,000 to save 15 minutes a board of manpower …
how many boards do you need to make ,to make that pay for it self ???
so it takes a whole day ??
isnt making boards for a hobby part of the experience …
i can see so much progress and learning going on , it stokes me …
i think dave alluded to the fact that putting concepts out there would help me solve problems ??
i can assure you dave , the problems im dealing with now are a little more complex …
most of the guys on this thread are light years ahead of standard p/u builders , just in basic comprehension of how sandwich starts to effect performance , now a stack of ideas are being put forth to address observed performance differences …
there are so many design myths that will be debunked over the next few years based on whats happening right here …
those myths are like superstitions that keep people in the dark about whats really happening under your feet in the water …
was surfing snapper yesterday . met a guy with a really heavy board and he reckons you need weight to carry speed and going to light works against you …
i might have believed him if i wasnt going 3 times faster , generating speed in spots he could only coast along in , then having my board carry me across the dead spots to a finishing point way further down the line …
unless your trying to solve problems in this area , you just wont get it …
o i forgot to mention , this guy was a previous national champ , so he had more than enough ability …
dave i heard you met one of my team guys a few days back , and you discussed a similar subject , so i thought i would throw those comments in …
he may not have had the ability to explain why his board does what it does , but he knows how it surfs in comparison to other boards , and knows that current design theory is flawed in many areas …
great thread …
keep up the good work guys …
dan , i checked that board you made (9’ x 24 x 2.5 )… any finished full pics yet ???
dave i should have mentioned , when i put stuff out there , it wasnt to get ideas or have others solve problems for me , it was mainly a way of finding crew who would have the ability and ingenuity ,to want to work with in the future …
you could call it , creating a shortlist of potential partners …
because of sways , ive hooked up with a lot of crew to bring this stuff forward …
ok thats me …
glad to be back in touch with the world …
regards
BERT
Hey Bert, welcome back from the land of the lost. I don’t have any pictures of the final board (and probably won’t take any 
) I sprayed the gloss coat with the can version of upol. Its a lot harder than it looks! In places the gloss looked great and in others it just wouldn’t shine up. I think going with the spray cans was a big mistake. I really like the urathane and don’t think I’ll go back to a gloss coat (where it turned out good it looks great!), but next time I’m going to spray it with a sprayer. None of that affects how it surfs, but the lack of gloss really detracts. This is the first board that I’ve build that I think actually improves how I surf!
So much good info in this thread. I found this picture a while ago and
thought it was relevant here. It’s a snowboard core that’s using carbon tape
under the feet to transfer the energy out to the rails. Thought it
might spark an idea for someone. You could use the carbon instead of
the balsa stiffeners under the deck to stiffen up certain sections and to
transfer loads where you want them to go.
I caught it, Mee. The far background. The 3rd reef pipe of balsandos. Skins with blocks already on. 8)
Oneula - just make the skins flat. Like DanB said, once the glass & balsa are put together, the glass will flex because the balsa is so thin & the balsa will conform to all kinds of shapes without splitting because the glass holds it together.
Remember, Dan used 2 different kinds of resin. A stiffer one for the deck & a more flexible one for the bottom. If I remember right, he said after his pre-made skins were out of the bags, he could flex his deck skin into a big arc but could practically roll his bottom skin into a tube. There’s a lot of information & potential, right in that.
Bert’s talking about tooling & pre-planning & space for the rails (thanks, again, Bert, for taking the time to get back in here)…to me that sounds very far from tape & glue…solid pieces & rail-shaped clamps (offcuts? vac bag?) to slap them together. Waste a little balsa & save a lot of production time…
Bert also said something months ago to Dan about thinking about building boards “inside out”. That’s the key to the skins, I think. Dan really figured this out & told me about it a month ago or so. Put the outside glass on the balsa before anything else…who would ever conceive of doing your exterior lamination before you even shaped the blank? Sounds pretty freakin’ inside-out to me. 
Then the tape thing. Finally, the pieces came together. Its going to be a busy winter
Bert also said something months ago about building boards “inside out”
Its even more than inside out. Its the inner board and the outer board. On a traditional board you really have one board since the core doesn’t really add anything. With the componentized board you end up with multilple boards. The outer board which keeps everything dry, and the inner board which you actually surf. It really doesn’t take much glass to keep the board intact since the low resin ratios really improve the strength of the glass. If you overstrengthen the outer board it will prevent the inner board from working. Here’s why I don’t think you can get away without modifying the eps. If you were going to describe your perfect board would you use terms like trampoline or air matress. Eps left on its own is an air matress - sure it light but its meant to be sleep on. On a trampoline, everytime you jump it stores your energy and rebounds you. If you surf a trampoline the rebound will help to dig the rail in and project you out of turns. If you only worked the tail of the board you wouldn’t need to things like springers, but if you are trying to make speed down the face of a wave and are more centered on the board a springer will allow you to store the energy thats generated through pumping the board.
I think you are really on to something. I was amazed on how it looked like a scaled down version of the internals from one of Roy’s wooden boards that Rhino posted. It makes sense to me now that that everyone has switched their skins from the straight wood patterns to the diagonal that internal stringers would do the same.
How do you think it would affect the flexing if you moved into the center like Dan is doing? It would be hard for people working from solid blocks but the Home Depot glue ups might be able to come up with an amazing board with out traditional or parimeter stringers.
I put some balsa st(p)ringers underneath the deck of the most recent board I completed with the intention of stiffening up the front end of the board and leaving the tail (middle stance->tail) free to flex. Seemed to work very nicely as well. Nothing as complicated as the grid, just one 3/8" squre piece down the middle, 4ft long and two 1/4" 3ft lengths kind of off at and angle going from the nose towards the rail at and angle. I’ll be incorporating it in the future, for sure.
The “outside in” method seems to just make sense…man…nice detective work guys. Would seem now that we’ve got some research to do. I’ll try some test panels before I go whole hog on this, 'cause no doubt, resin viscosity, vaccuum pressure and cure times will affect the kind of saturation you get. For those who have tried it, perhaps we should be keeping tabs in a different thread about how much resin is required to saturate balsa of X-thickness applied with Y-pressure…seems that the glass equation is pretty much worked out…1:1, but with the wood being as porous as it is, I’d imagine you’d really need to compensate for the resin that ends up in the wood. I noticed good bleed-through on the deck of my board when I vac’ed the deck on; wet glass in between the wood and foam; resin pulled up through the wood to the outer deck, but neglected to keep my numbers…
Man…I wasn’t going to build anything for a while, but now I think I’m too stoked!
DAMN you Swaylocks!
Man…I wasn’t going to build anything for a while, but now I think I’m too stoked!
I totally agree! There’s nothing like progress and new directions to make me want a new board. Unfortuanately, I still have more to figure out on my current one before I move forward.
Can anyone explain what glassing the outside of the board first will do to the ride?
I don’t think that glassing the outside of the board first necessarly effects the ride of your board, but it does dictate different construction techniques that I think helps the flex of the board. The main benifits I see so far is that it easier to make an nice looking skin, it reduces or eliminates balsa outgassing, the weave lays flatter so you can sand off even more excess resin, the skin gets longer cure time because its made first so it is stronger when you rush it out into the waves to soon. no tape on the inside of the board. That being said…
While I don’t think that I’ll ever build a balsa board again without preforming the skins my next board will have balsa bottom and rails (both preformed) with a corecell deck that will be glasses traditionally. This will leave only 3-4 ounces over the rails. We’ll see…
but it does dictate different construction techniques that I think helps the flex of the board.
oh yeah, how so?
Brother Ben just a comment/observation for you and DanB to ponder…
I don’t think Bert’s deck skins are epoxied to the EPS at all (look at John’s photo)
Maybe the bottom, but I venture to guess the deck is only securely fastened to the solid rails and perhaps some type of flexible adhesive is used to softly bind the deck to the seal EPS foam. This means the rail bands have to be thicker and more solid that our current build out maybe even some glass in between the layers to add weight and strength if using thin balsa sheets instead of short thick scarfed wood bands as you mentioned. Like Bert said you pinch hard only at the seams to get the best flex. A springing flexible deck and solid bottom would give you the ability to transfer foot pressure to the rocker profile and provide a solid base for fin reaction at the same time. The springer inserted under the skin is to stiffen the board in places you don’t want too flexible like under your feet or push up areas still not attached to the deck skin though.
Spray seal or epoxy seal the foam for water protection and bind the deck to only the rails. You can use a flexible urethane sealant between the sealed foam and wood sandwich but I would presume that’s optional. This is also why I believe Bert’s wood sandwich is probably glassed (via heat seal) on both sides during the pre-build stage 1-2oz on the inside and 4-6oz on the outside.
We’ve just tried to set rockers on floppy flat 2" thick 1lb EPS by lamming on the bottom sandwich on a wooden rocker table with weights and ended up with a 2" thick piece of floppy flat 2" thick EPS foam with wood on one side. Which tells me that even with glassing both sides of the 1/16 wood sandwich it still will be a pliable layer you can vacuum on to a complex surface kind of like using 1/8" corecell
Need to start pre-building out some 2’x8’ balsa lams and balsa rail band sheets to give this a test.
Always nice to have a stack of prebuilt 2’x8’ balsa wood lams and rail bands lying around to pop out a new design on a whim.
As far as springers…
CMP’s thinking about diving boards and how you adjust the fulcrum point to adjust for the weight of the diver and the desired bounce. The question is how do you build an adjustable fulcrum point to be able change the flex pattern of a single board design as needed… Possible answer is to do it like sailboarders adjust tension on their sails… maybe it’s routed in hollow carbon tubes and inserted shafts of different materials.
Who knows…
like honolulu said it’s all speculation and dreaming at this point until you build and test one…
In past boards I’ve always locked both top and bottom skins to the board (I just liked the way it looked) to the rails. With the premade bottom skin it is almost impossible to do so I ended up having the bottom skin flush with the stringer. I didn’t think it would make a difference but it definantly did.
Its much easier to use different types of resins (thats why I ended up with 2020 on the bottom and 2000 on the top)
You are forced to use the glass tape for the rails. This means you can have a heavier glass on the deck for stregth and less glass on the rails for flex.
Yes, you could do all of these things glassing traditionally but its easier to do them with preformed skins
I not saying that he doesn’t but what would be the benifit of not epoxying on the deck skin. It seems that any vertical movement of the skin would break down the eps in no time flat.
interesting.
can you provide the raw finished dimensions of the two boards you are flex comparing? length and thickness in particular.