I have to start this post off by saying thanks to everyone on the sways. The wealth of knowledge in these pages has guided me through the creation of five pupe boards and pushed my knowledge through the roof in design and alternative materials. In fact, when I start shaping I feel like my knowledge so far surpasses my skill that it becomes frustrating trying to get the board how I want it to look(Most people I know who start shaping rarely have that problem, until I tell them about this site). I’ve been lurking for a long time (maybe a year and half) and I know that everytime I log on I’ll at least come across something that peaks my interest whether it directly related to what I am doing or not. Every surfer who doesn’t spend time on these boards are doing themselves a huge disservice.
Anyways,
All this talk of sandwich construction has been brewing many possibilities in my head. So far from what I’ve read it seems that the idea is a lower density foam wrapped in a higher density foam and then glassed (very basic).
But, what if the reverse was done?
Say you start with a low density foam (for weight) and to bond the outside layer you use an epoxy with less flex and a glass that is very strong and rigid, such as carbon fiber. At this point not very surfer friendly. Now for the outside layer of foam you use something with a lot of flex and good Rebound(? from compression). This could then be glassed with a lighter layer of more flexible(maybe a single 4 oz. E) cloth using an epoxy with more flex. Now you have a strong rigid board that is allowed a certain amount flex from the slight compression of foam(sounds bad I know) and the flex of glass. The inner rigid piece would be very strong and more resistant to breakage while the outer cannot be flexed to the point of failure because of the inner piece. With this technique you could even control the amount of flex by changing the distance from the inner layer to the outer layer on the base and how stiff by the resilience(?) of the outer layer foam. You could also control how responsive and forgiving a board is by the distance of the inner layer from the outer layer on the deck.
I definetly see some problems with this, such as pressure dings, and I also have no idea what kind of foam (or whether it would even be foam) to use for the outer layer.
Maybe it’s a bad idea, maybe it’s not, (I can’t tell due to lack of experience with some of the materials) and maybe it’s already been explored so that’s why I leave it to you guys. I’m eager to hear where this goes.
Yeah sort of the same idea, but I was thinking more along the lines of getting flex exclusively from the outer foam core, while having little to no flex in the core itself. This way you have a very strong board (in theory). The inner core being strong in itself, but to gain this strength you will most certainly lose flex. This is where the flexible outer layer comes into play, it moves around the rigid inner layer. This flexible layer would be more susceptible to breakage but the inner core stops it from flexing all the way to it’s break point. The result should be a stronger board.
Soloman and surflight incorporate the flex into their core materials, but are the closest thing in production to what I’m getting at here.
Yeah sort of the same idea, but I was thinking more along the lines of getting flex exclusively from the outer foam core, while having little to no flex in the core itself.
Kind of like a Boogie board with a rigid board buried inside??
This way you have a very strong board (in theory).
The inner core being strong in itself, but to gain this strength you will most certainly lose flex.
This is where the flexible outer layer comes into play, it moves around the rigid inner layer.
This flexible layer would be more susceptible to breakage but the inner core stops it from flexing all the way to it’s break point. The result should be a stronger board.
Soloman and surflight incorporate the flex into their core materials, but are the closest thing in production to what I’m getting at here.
[=Blue]As noted above, I think you are pursuing a “been there done that” idea. The only real difference being HOW flexible each of the parts are designed to be. That doesn’t mean that you can’t improve on it. Make one and tell us all how it works.
Now it comes to HOW soft is the shell, and how thick.
Say you want a 2.5" thick board. Shell maybe 1/4" waterproof dense foam, so core is 2" thick. Problem is tapering at nose and tail, as thin core will bend snap, or twist, and there is no monocoque strength from the shell, where most of the strength lies with traditional boards.
French companies often soft shell their EPS or Poly cores, but 1/16" is very heavy and very flexible, not much for performance.
I’d imagine some sort of new Airex derivative, with a smooth outer without fiberglass, might just work if the shape is not too well foiled.
theres no reason u cant use foam on the outside of a board either
i doubt u would need much carbon if you were to use mutiple sandwhich consruction
surflite use EPP foam
i think this foam has huge potential looking at what there doing with it in the auto industry
i was thinking along this idea as well
expensive experiment however
has anyone figured out berts indestructible flexible board yet
i bet that aint standard materials ?? ie eps and corecell or is there more to it
im suspicious that it is a multi foam construction perhaps using epp thermoformed sandwhich bonded with a polureathane or SMP adhesive airex or corecell on the outer skin
When I started this thread though my idea wasn’t really geared towards boogie board foam. I was thinking more along the lines of a disposable board ( low density foam with single 4 oz. on deck and base) with a stiff core sandwiched inside. This idea works best if the core is:
a. closer to the deck. This will make the board more responsive because none of the pressure from the rider is lost to energy absorption by the foam under the feet.
b. most of the soft core and compressible foam is near the nose and tail to simulate flex. Where a normal board flexes in the middle to create more rocker this board would compress in the nose and tail to increase rocker.
So what we actually have is a stiff core that remains the same, foam that compresses (more near the nose and tail), and the only thing that actually does any flexing is the outer glass job.
The foil would still be a slight issue.
I wish I had the money, time and tools to test this theory. These things are all hard to come by being a student.
Your idea is to have a rigid core with a soft outer layer. . . . . what exactly do you see as the possible advantage of such a board ? You say that you would be able to control the amount of flex in the board but the system which you describe has zero flex, just a soft surface, so if the rigid core/soft outer layer board has an advantage it would be something other than flexibility. . . .like what, the squish factor? Sorry, I don’t get it, maybe I am too rigid in my thinking !
HAHA, yeah Tom Bloke in your use of sarcasm you actually nailed what I was going for. The “squishy factor” (compression) is exactly what creates the “illusion” of flex. The key is to put the compressible material in the right places (ie base side of the board in the nose and tail). When a normal board flexes it increases rocker resulting in a tighter turning radius. The same is true here, foam in the nose and tail are compressed against the rigid inner core while being pushed through a turn, the rocker increases the result is a tighter turn.
Why don’t all performance shortboarders looking for the lightest product available ride a board that’s glassed 2 oz top and bottom? Breakage is the obvious answer.
So what do board manufacturers do? They try alternative materials that are lighter and stronger. Unfortunately these materials’ flex characteristics are different than that of the PUPE that we all know and have come to love. So using these strong alternative materials to make a rigid internal structure we can use an outer layer to simulate that flex using compression.
Take that same board that’s glassed 2 oz. top and bottom. It breaks so easy because it flexes to the point of failure. If you add the rigid internal structure to this board it stops the board from flexing ALL the way to the point of failure. The foam in the nose and tail that is being pinched between the rigid inner layer and the glass on the base is what’s being compressed.
I couldn’t recreate the flex I get on my current board using a compressible material with rigid backbone because the board flexes up to 6 inches and is only just over an inch and a half thick. . . . so the maximum ‘flex’ due to compressing the board would have to be less than an inch, which wouldn’t do.
Changing the rocker is only one reason for flex, another is that it is a means of turning rider effort into forward propulsion. . . .storing energy and releasing it kind of like (but not exactly) longbows or diving boards do. Can you visualise a ‘squishy’ or compressible material actually providing the same ‘spring’ effect as a flexible bow, board, rod, golf club, or diving board?
Maybe I should’ve further explored all the uses of flex :0p
When it comes to flex I’ve never seen anything as insane as the board you showed in that WMA file. How does that thing surf, I bet it has quite a “lively” feel, to say the least.
Why don’t all performance shortboarders looking for the lightest product available ride a board that’s glassed 2 oz top and bottom? Breakage is the obvious answer.
Aloha Foster
Not necessarily so. 2oz will often flex too much and not return with enough snap and authority. Of course, it can also break and ding easy, but if it doesn’t surf well or surfs like a wet noodle, breakage is a secondary problem.
Are you assuming that 4oz won’t allow enough flex? Too much flex or uncontrolable flex isn’t just about breakage, it is about loss of power, punch and control. Though both are important, breakage is secondary to performance.
So what do board manufacturers do? They try alternative materials that are lighter and stronger. Unfortunately these materials’ flex characteristics are different than that of the PUPE that we all know and have come to love. So using these strong alternative materials to make a rigid internal structure we can use an outer layer to simulate that flex using compression.
Depending on how flexy… flexy materials are seen to be, simple solutions to what you describe may already be in existance. I consider, thin, 4oz boards to be pretty flexy. Especially in the power of Hawaii. Sometimes too flexy. Maybe the way you would view 2oz boards.
I often add fiberglass rods (mentioned in some previous post of mine) to support the thinner, softer foam and 4oz, so that the board can flex easily, yet progressively builds up greater resistance to that flex the further it flexes. This also causes it to snap back with authority. And helps resist buckling or breaking as there is no place along the rods where the forces will load excessively.
There are many ways to solve similar problems. It often depends on which is more important. The actual remedy of the problem, or the execution of a particular idea as the solution. If you are looking for a progressive, rising rate of resistence to flex, there are many, fairly simple, ways to achieve it.
Take that same board that’s glassed 2 oz. top and bottom. It breaks so easy because it flexes to the point of failure. If you add the rigid internal structure to this board it stops the board from flexing ALL the way to the point of failure. The foam in the nose and tail that is being pinched between the rigid inner layer and the glass on the base is what’s being compressed.
As Roy mentioned, on thin boards your method may not have enough compressible material to allow enough flex or authoritive return, so as to provide the results you are looking for. Still it is all fun to to consider and think about.
How about a compressible surface AND a flexible board ?
BTW that board has just had a resin job today and will be ready to hit the water soon. . . it’s a longer version of my old flexy balsa 12 footer which was, as you suggested, alive in a big way (a very similar flex), and which got loved and thrashed into early retirement. The extreme twang really came into it’s own when the waves got bigger. . . can’t wait !
