having great results with performance and strength.
changing the carbon layup changes flex patterns quite a bit.
boards definately seem to work best when loading up on the rail and near or in the pocket type of surfing. i feel the boards suffer a bit in the “transition” game and when you need them to run down the line. they get a bit “lost” and dont’ seem to find/draw a natural line.(watch video of Taj surfing and you can see what i mean)
tim - i know what you are talking about with the performance through the roof in the pocket and sub par in slower parts of the wave - the stringerless I have accentuates this the most, the pvc perimeter stringer does this also, but this carbon railed board seemed to bridge the gap - it was not quite as radical in the pocket(still really good), but it still felt good running down the line and through flatter spots on the wave. how much of this effect do you think is due to the fact that these boards are lighter in weight so they carry less momemtum, regardless of their flex?
That looks super fun. If I had the funds to build another board (period) I would want to try this construction. I am interested to know how it would work if less carbon was used on the rail, and then a strip used down the center of the board on the bottom would work. This way you get the rail stringers that seem to help in the pocket, but also some of the feel of the center stringer for the flatter parts of the wave. Anybody know if this has already been tried?
I am interested to know how it would work if less carbon was used on the rail, and then a strip used down the center of the board on the bottom would work. This way you get the rail stringers that seem to help in the pocket, but also some of the feel of the center stringer for the flatter parts of the wave. Anybody know if this has already been tried?
I’ve done it, in a way. I tapered the carbon rails and did a 3/4 carbon/kevlar deck patch ending about a foot from the tail. The idea was to stiffen the board through the middle and keep the flex in the tail. The two boards I’ve done it on go really well, but honestly, I couldn’t tell you if it was from the CF and Kevlar, or just the outline, rocker and fins setup.
No, it wont. It will dramatically increase the stiffness. It will improve the strength since you are adding more fibres. Best you can do to improve strength is adding buckling resistance (bonding strength to the foam), I like to add a fake stringer (routed 1 or 2 cm deep), but there are many other good solutions.
High density foam would work very good as a fake stringer. Adding fake wood stringers also works fine.
The problem with carbon is that people believe it it strong. It is indeed slightly stronger than glass, but a lot stiffer, and that makes carbon very brittle.
In the composite industry, carbon is never chosen for it’s strength but for it’s stiffness. Have you ever seen carbon fibre ropes (e.g. for climbing or fishing)? I haven’t, but I’ve seen nylon, kevlar, dyneema,…
Why don’t you just add UD glass tape? This is cheaper and tougher.
sometimes, it is impossible to see the forest for the trees…
Hi Hans,
thanks for your input!!
So what would be your setup then? I can get 220 gr UD glass tape, 100mm or 60mm wide. 100mm just on bottom or are 60mm enough? Or 60mm on top & bottom?
Maybe different setups for 9’6 XPS-SUP and 9’6 EPS Longboard?
And what would be the corresponding glassing scedule for both boards?
Still want to go with carbon rails. I like the Idea of the parabolic stringer and I want to to try it…
I will not stop you from using carbon, carbon is valuable if you use it for it’s stiffness (as opposed to dampening), sometimes referred to as “flex return” in the surfer slang.
Now about your glass shedule. I’ve build some XPS boards with 2x5oz, some locally even have 3x5oz (165g/m2 to be exact). They all got pressure dents that eventually turn into delams. However I have a handy solution for that: Just punch a hole in the delam so that it won’t blow up, XPS is waterproof anyway. But prepare for friends joking about your “leaky boards”, yes my favourite board wets his sock ;).
I really like XPS because it is very low maintenance. I had a fin in one of my boards, a 10cm cut, never fixed the damage since it’s on the deck. And guess what the board still surfs great and nobody will steal it because it has become so ugly. Here is the build thread of that board: http://www.swaylocks.com/forums/65-project-indian-surfpics-snap-repair
So is 5oz enough on the deck? I wouldn’t do it. Considering a deck sandwich is a good idea on XPS, altough I never did that.
Oh yeah, almost forgot. Never sell an XPS board, unless you are 100% sure that you never meet the customer again and that you keep your name secret.
Sorry, I can’t. You want to make your board stronger. It is very difficult to quantify that.
I don’t know how strong your boards usually are and how much stronger you want them. It really is all trial and error.
However I really recommend the fake stringers. I broke 2 boards and they both broke by deck laminate buckling.
If you ask me how I would build this XPS longboard, this would be my shedule today:
One real stringer and 4 fake stringers (2 deck + 2 bottom), so that it looks like a triple stringer board.
Bottom: 2x5oz
Deck: 2x5oz with 5oz patches
I would use the UD glass tape around the fake stringers. So that the UD tape is folded as a U-profile around the fake stringer.
But remember, I guarantee nothing, this is just what is on top of my head right now. And I am an amateur builder! (with an electromechanical engineering degree)