Speedy's comment about Stiffness Distribution

General Discussion
61

Silly the surftruck does turn but it turns to reduce toe in, and has a stop at the normal toe in angle ( according to everything Blakestah says)

That spray coming off the rail is just an inefficient waste of energy and ideally shouldn’t be there in the first place, concave helps to reduce it, so i have to disagree, spray should be impeded before it happens.

Spray making is just a flashy thing to do for the cameras, turning with hardly any spray isn’t impressive but is way more efficient, the whole ASP competition thing is based on style and making big gobs of spray, fans of spray etc for judges and cameras, don’t assume that it is necessary hydrodynamically to throw as much spray as possible.

By the way can you guess what the most efficient way to reduce spray during turns is ?

It isn’t concave !

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62

Aloha Benny

Yes glassing schedules can effect flex and experienced shapers and board builders will use all the materials at their disposal to achieve various results.

Yeah, a comment from Griff or Barnfield would be great about now, as they shape & glass all in-house.

Just a correctionn Benny, while I do glass my boards in house and currently do it personally, Griffen doesn’t have his own glass shop and doesn’t “glass all in-house”. He uses various outside glassers.

or that matter, I’d be fascinated to learn if there’s ever shaper-glasser communication regarding this, like, “Hey, TFAD, I want a stiff tail so cut the laps bigger back there, ok.” Or even, “Hey Kokua, how about an extra tail patch to stiffen it up back there?” “No, that’s not necessary, I’ll just cut the laps a little wider in the back.”

Vary few surfers understand glassing and flex issues such that they discuss glassing techniques or materials for the purpose of tuning the flex in their boards. Most have short attention spans and prefer a pile of boards to be waiting for them, half of them they will dismiss without even riding.

Maybe that’s in the realm of trade secrets. Anyone want to send me a PM for personal use only? I won’t spill.

No big secrets here, just so many variables that it is very hard to discuss them in any kind of detail.

Below is a snippet from one of my articles on this subject almost 30 years ago. There is a lot of talk on Swaylocks regarding the subject of flex. It is often presented as new, or “invented” by someone. Fact is. Good designers have known this stuff since the beginning. Some employed it better then others.

[=Red]Material Stiffness . by Bill Barnfield . February 1985 . Builders’ Emporium . Surfing Magazine …

Stiffness or flexibility imparted to a surfboard by its material composition is often unnoticed or misunderstood. In the search for lightness of the finished product most of the emphasis or credit is given to the weight of the various materials rather than their effect on flex. Some shapers, after discovering that the use of smaller stringers greatly improved the function of their boards, have failed to follow up on other ways to improve the flex of their boards, often because they attributed the improvement to a drop in weight rather than a change in flex. Not that weight changes don’t have substantial effects on function, it’s just that credit must be given where credit is due or an unbalanced assumption may result and eventually reflect in the future composition and execution of designs…

63

Sup Bill,

Do you think that most practical options were explored back then or would there be room for improvement and tweaks because of things like better epoxy resins? Or was most of this done on poly? I’m not asking about specifics but the context and how it may relate to ‘30 years after’. If that makes sense.

64

This is a good thread–except for Roy’s latter input, which completely neglects the spray’s importance as a propulsion element.

snicker

sorry to distract anyone–couldn’t help it, eh wot, Roy?

gerg

65

Sounds like we’re getting into the realm of spoons. With solid resin you can at least sand to tune flex (and flexspooners do). Designing flex in through shape is a lot more difficult and I doubt anyone has the will to grind back laps in an effort to tune flex.

Still it’s interesting. I may glass my next board light top and bottom and double up on rail laps - hang on - that’s why spoons always snap - the 3-D rails can’t distort enough to deal with the flex in the integrated top and bottom decks (aka 12-18 layers of glass). I’ll have to use highly flexible rail material…

66

I think its a great idea to schedule and tune laps, primarily because its a last step process in finishing the board, less invasive and reductive. Who wanrts to go back into the guts and foil skins. Let me tell you about a cracked out skin head who couldn’t deal with faring out 4 oz S-glass bottom laps on a 7-0 poly/ PU; he decided to grind them completely off to the rail tuck through out! First day out… I buckled it duck diving perfect 6’ pealing surf; didnt even get to ride it… except in… on my belly. After attempting to re wrap the rails and far it out myself…it aways showed rail zippers due to flex… another cursed abortion that eventually snapped in 8’ Thanksgiving day surf. I WAS thankful… to be rid of it… and the glass shop that built it… and ground it like cheap GE coffee.

67
Quote:
Sup Bill,

Do you think that most practical options were explored back then or would there be room for improvement and tweaks because of things like better epoxy resins? Or was most of this done on poly? I’m not asking about specifics but the context and how it may relate to ‘30 years after’. If that makes sense.

Aloha Ozzy

There was pretty much all the materials that are around today. I can’t think of anything that is significantly newer or better than what was available then. Small changes and improvements have come along but nothing revolutionary in materials. Not that these improvements weren’t important, especially when joined with other improved materials. But just nothing singularly revolutionary enough to drive significant changes.

Was what was available being taken full advantage of back then. Absolutely not. Could more have been done… For sure!

Why wasn’t it…??

Board evolution is a curious thing. Sometimes it is driven by surfers needs sometimes by board builders creativity. But they are tightly integrated and very hard to figure out which was the stronger influence.

Beyond them all exists a primary release agent, that frees up creativity and drives it forward. That release agent is boredom in a matured product.

Longboards in the late 60’s had pretty much fully matured. Releasing and driving the creativity the manifested itself in the shortboard revolution.

10 years later, single fins had matured releasing the creativity the manifested itself in tri fins.

10 years later tri fins were pretty well matured but the commercial interests were so well entrenched that nearly another 10 years would pass before the boredom with maturity broke through the commercialy driven and entrenched status quo and released the next new thing which manifested itself in molded boards built with new construction techniques and materials.

Now it has been another 10 years and the molded (some call them “epoxy” boards) have hit maturity and the boredom is spawning things like FireWire.

No matter how cool the materials or construction techniques in the “new” tech are or can be. There won’t be enough effort or focus on them to drive widespread revolution, unless the current materials or construction technniques have reached a certain sense maturity, commonality and boredom.

Kind of like new surf spots not being discoverd until the current ones become overcrowded. Not that a few don’t explore new spots or new materials, techniques or designs. It is just that they won’t become mainstream unless the existing things are boring enough and the new ones are good enough and different enough to upset the status quo.

Boredom is the mother of invention.

68

benny

ive built stiff composites

cut the rails off with a saw and they are still stiff

ive built fully glassed composites other than the rails

and the change in flex is neglible after glassing the rails

hope that confuses everyone

69

Boredom is the mother of invention.

Good one…it is for this tinkerer!

I think Silly’s proly one of the rare few to have cut rails off and tested. But that’s compsand which is a diff animal. Ive glassed foam models and the rail glass, that wrap with a small shear web, makes a diff. Its also an area of stress concentration. The more layers you have around the rail the stiffer it gets.

Every ounce of glass/resin makes a diff. It makes an even bigger diff depending on where those ounces are located. Ive stiffened sections by putting in a short sliver of glass along the rail. When I cut my laps, I vary the overlap as I go along, a bit more wrap towards the front half of the board.

Yeah laps makes a good diff. So does thickness dist. So does resin modulus. In general, those are the three biggies IMO.

HTH.

70

Sup Bill,

Great insight. I’m stoked you joined the discussion.

Interesting concept of things reaching maturity, getting boring, and that driving the creativity that brings new techniques. It sounds right on the money for the most part. And maybe the general acceptance plays a big factor in what designers think will be appreciated and utilized by surfers. Otherwise why I want to try to build a better [or more effective] mouse trap if people aren’t having problems with mice and have no desire to worry about it. The status quo is fine. However, I feel a major driving force relating to this flex topic is the edge factor. People wanting an edge on the next competitor, or wanting an asthetic edge with all these beautiful wood skin compsands coming out. Not that people want them ‘only’ because of this. And also performance oriented people that are never satisfied. Thank goodness for the few that keep pushing, eh?

I’m not in exactly the same situation as the majority in this forum so that ‘has’ to color my opinion somewhat. I’m a shortboarder for life. I love high performance. I started surfing when Martin Potter was slicing and bashing everything in sight. I focus on standard eps & epoxy contruction. Even if I was just making the occasional board for myself, or conveying this attitude to a shaper that’s making me a board. This is what waves my willie and picks my direction for me. I have to do what makes me happy. That’s my mother of invention, although I’m not ‘inventing’ anything.

As I sit here waiting for another no-show on a construction project, I look back to people that came to me and wanted to step out of the box a little. Not many at all. Thanks for the few that did. Because after all, it is still experimental in a sense and not many people want to chance it with what little money they have. I understand that completely. I would probably feel the same way if I were in their position. My greatest fear is disappointing a customer.

71

Good stuff Craftee. I was thinking of using the 70s Power Rods you mentioned as an example for discussion purposes.

72

Ozzy, do your EPS/epoxy boards have stringers? Do you use them as a real changeable & dynamic factor, or more of a visual reference and a constant, like the foam itself?

Bill, I’m beginning to understand that your comments indicate that its possible to be a 97 or 98% glasser, making beautiful & functional, and occasionally even ‘magic’ boards, yet never understand - let alone optimize - the last 2 or 3% of technique & materials that create quantifiable (& reproduceable) results. At least, that’s exactly what I got out of your comments on that old thread about the shaping video…there are hundreds of great shapers who make perfect boards, but only a few who can do them over & over again, all the while minimizing wasteful motions and utilizing both craftmanship skill & design knowledge to their fullest.

Its almost enough to send me where Ozzy is - so much to learn with just the simple construction that it can seem that making composites is going too far. Is that why you don’t? Sunova, Firewire, Surftech, Aviso… no need, if you can truly optimize your use of foam, resin, and glass? If you can build a ‘perfect’ board without complicated composites, than you don’t gain anything more by using them?

How does materials life expectancy factor in? How many flex cycles does a ‘perfect’ pu/pe board have in it before the ‘magic’ is gone? (This is not a hidden prop for composites, or even epoxy, but an honest question.) Or do you feel that surfers who can really benefit from the 99 or 100% boards shouldn’t ride the same shape for years on end, but should work with their shaper (and glasser) to evolve their shapes (and glassing) to keep getting better? Have you ever had a customer who matched up so well with a board that he shouldn’t change a thing for the next one?

73

I come from a kiteboard building background. The advantage that we have is that the core is a high density foam that can be easily tuned for flex by thinning the core. No need to worry about floatation either.

The basic design theory is to provide a board that has good flexion qualities on the bottom and good compression resistance on the deck. By thinning the core at the tips you could tune the flex pattern without having to do an exotic lay-up.

In the search for the elusive perfect board, builders have experimented with carbon in x patterns, rubber, wood, pvc rails, and on and on. Use of wood marine ply heel dent reinforcements as well as balsa cores or stringers created problems because the wood varies too much in its flex patterns from piece to piece and even along it’s given length. Instead of having a basic starting point of a planned flex pattern the wood would usually skew the whole thing.

Most of the major builders recognize the superior properties of wood’s resistance to compression and its quick rebound for snappy flex. In order to control the inconsistencies they have turned to the snowboard industry’s uses of multi ton presses and expertise with sandwich construction

I’m trying to apply some of these theories to surfboard making. My starting point has been to discount the foam as a part of the flex pattern. Been asking for the unidirectional ply stringers to help with flex irregularities and then treating the stringer as I would the core foam of the kiteboard, thicker less flex, thinner more flex.

The 64 dollar question that I have from some of you experienced flexinauts is what are your design goals? Overall linear flex tip to tail, stiff area between the feet, progressive flex towards the tail? I know that it is a lot to ask and it varies from board type to board type but this would be for a modern high performance board.

I’ve been leaning towards flex patterns that follow thickness foil and the use of perimeter stringers to control twist. Glassing schedules would be for compression resistance on the deck and flexion on the bottom. Full progressive concave in the tail flowing with thickness foil to help with torsional twist of the tail as it thins out. I know this holds true for a kiteboard it’s just been a challenge with the floppy foam and larger surface areas of a surfboard.

74

Great contribution, DMP. Sounds like you’re talking directionals, not twin tips (based on the tail concave comment)?

I’ve made a couple KB’s. And then Cj3 gave me a couple extra blanks, and, in turn, I gave one to Wells. When I handed it to him, he said, “Wow, I guess this is what a surfboard would look like if we never had to paddle them.” Awfully insightful comment, really. Especially considering it was only 1/2" thick. :slight_smile:

On a directional, do you thin both ends? With the ply stringer, are you talking center, perimeters, or spaced about 6"-10" apart to be under the heels & toes? Concaving any decks - and if so, does that make them more or less flexible? Do you wrap your rail glass, or fill the edge & grind it smooth? I’ve found that wrapping the rails is problematic on a rocker table, but filled edges aren’t nearly as stiff. I had to add an extra layer of glass to each side to produce sufficient panel stiffness on the filled-edge board, when I probably could have achieved the same thing with a small strip of glass around the rails.

Thanks.

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Ozzy, do your EPS/epoxy boards have stringers? Do you use them as a real changeable & dynamic factor, or more of a visual reference and a constant, like the foam itself?

Stringers are very real and very dynamic. If I need a visual reference I’ll use a chalk line.

77

I think anything can ‘help’ someone surf better. But I don’t think there is such a thing as one feature or effect that will make someone surf like a pro, unless they’re a pro already.

To me this is an art not a science. Albeit an art that requires a high degree of technique and expertise. My group of effects that helps me get the absolute most out of my surfing may be a total pig to you. And vice versa. I think that’s the beauty of it. It’s so individualistic. That’s why everything is so subjective.

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This a really stupid question

but it probably needs to be asked at this point with all the hype…

But can anyone here

quantifiably and prove statistically

that any of the new tech stuff

can actually make someone surf much better

than they could

with just a well crafted and properly designed surfboard made from standard raw materials

for the individual in the first place for where they surf?

and if so

by how much?

10%?

25%?

In order words

what is the better board?

just a longer lasting board?

or a board than makes you surf better

than you could without it?

We hear alot of subjective interpretations

but I don’t see alot of fact other than a bunch of diagrams.

What I’d like to see is some amateur on the cusp

all of a sudden start winning contests or get a coverphoto in some mag pulling off some outrageous move

that they could never do with the best “normally made” surfboard.

How about a detailed “before” and “after” video analysis same wave same rider same move that’s how it’s done elsewhere just look at all the other sports.

The only new tech design outside of surftechs that I’ve actually heard of that’s been ridden and win in a regular contest by an amateur has been this weird looking Alexander Gemini design ridden by HopTong Smith at Local Motion’s Surf into Summer at Bowls and the Kamisuga’s in the northshore tow in contest. And yes I know the grom in Australia in the billibong world amateur juniors was doing well till a chubby Kekoa Bacalso kicked his butt on a standard PU in the finals.

To me this is the reality check

And something I have yet to see happen here

But I’d really like to see someone go at this scientifically and honestly

with some actual independant user trials and documented statistics.

I know there would be alot of volunteer test pilots out here

to try and prove the case either way…

Oneula you speak of quantifiable performance statistics and competition success in the same breath as if they are the same thing, but competition success is based on subjective criteria so is absolutely no use if you want to measure performance. . . . . it might sound quantifiable to say that someone won by 0.32 points but it’s just an opinion to two decimal places, and means nothing.

In longboarding for example, competition criteria is based on a surfing style which requires dysfunctional surfboards. . . it’s ‘low performance’ by legislation. . . and competitions in longboarding are like motor races using cars with square wheels !

We can’t even prove that we exist, so if you want absolute proof of anything surfing related we are up against it, but a good place to start is measuring speed. . . . . it is quantifiable, and every other board manufacturer claims plenty of it, so it is obviously an important yardstick.

There’s also the point that it is getting rather old hat to assume that ‘performance’ only means the ability to do ‘outrageous moves’ .

Surfboards are vehicles, and if we want quantify their behaviour on a scale of function then it might be a good idea to start treating them as such by measuring speed and designing for the ability to navigate waves efficiently rather than just judging their success as catwalk accessories

.

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Quote:

Bill, … … - so much to learn with just the simple construction that it can seem that making composites is going too far. Is that why you don’t? Sunova, Firewire, Surftech, Aviso… no need, if you can truly optimize your use of foam, resin, and glass? If you can build a ‘perfect’ board without complicated composites, than you don’t gain anything more by using them? …

I know you asked BB this, but I’d like to throw my 1 cents in also.

I don’t think composites are necessarily going to far. “I” just never felt the need to go there. Partly because I don’t have the resources for much R&D, and because I’m not trying to one-off anyone or anything to take the short path. Can the same thing be achieved with standard construction methods? Maybe. I don’t know much at all about composites so I can’t say.

I’m interested in hearing Bill’s response also.

80
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Stringers are very real and very dynamic.

So do you also go between pvc & wood; maybe bass, balsa & cedar; maybe t-bands and multiples, depending on what flex (and weight) you’re looking for in a particular shape?