How to stiffen my stick right up?

General Discussion
1

Hi everyone!

This board is too flexy once the waves get headhigh and over, nice waves.

What would you do to stiffen the board up? Anyone every tried to do so?

It is an eps/epoxy board… and max thickness is 2 1/8

I have 2 ideas now:

1=clean, sand and lam carbon strip lengthwise on bottom

2=clean, sand away 1 layer of 4 Oz, vacuum some 2.0 mm Corecork on deck, finish off with 4 oz on top, hotcoat and all…, adds a little volume too.

Any other ideas? 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Cheers

wouter

 

 

 

 

 

 

 

 

 

2

" How to stiffen my stick right up? "

 

 

…  **V I A G R A **

3

http://www.freeridersonline.co.uk/surfing-hardware/wax/viagra-wax-6-pack/prod_91.html

4

Benjamin Thomson said that he found that adding strips of fiberglass-reinforced packing tape was one way to add stiffness.  It may not be a permanent fix but you have plenty of chances for trial and error.  

5

I reckon cut the board in half lengthwise and put a stringer in it.

6

Do you already have two perimeter stringers in there or are those fat glue lines? 

If they’re stringers, I would say that it’s not flexing too much, and you might want to try out different fins in bigger surf. 

If they aren’t stringers, maybe try adding some fiberglass tape on the rails? 

 

7

Glass tape or carbon tape would probably do it BUT I would put it on the rails if you want to stiffen the board up.

The rails are where it would be most effective

8

If the only pupose is to increase flexural stiffness the most effective place to add fiber is the furthest of neutral fiber = where board is thicker = on top of deck.

9

Check this thread out. You can route a thin slot on the deck and add carbon like this guy did (or regular fiberglass), then just add a patch over the strip of carbon. Maybe follow the stringers, but offset it.

http://www2.swaylocks.com/forums/suspension-system-vernor-surfboards

10

I had a floppy longboard. I cut a trench 2 inches in from each rail on the deck then put some slow mix resin and some long strands of glass in the trench. Then a strip of cloth the length of the trench. Resin. Cured over a couple of warm days to make sure. Still has flex but no droop. 

11
  1. route a slot and glass in a stiff carbon rod (golf club shaft, old fishing pole) or a wooden dowel (if you want the board heavier).  for extra credit pre-bend it (like a bow and arrow without the arrow) and glass it under tension, apex up.  I did this on a fish once and it worked well. 

or

  1. add rail channels, but that will take some shaping then reglassing

or

always a good option…3) sell the board to someone lighter and make a new one.  .

12

 

Can you explain your reasoning here Lemat.

IMO, puting the extra cloth up on its edge adds more stiffness vs laying the cloth flat.

 

13

Just lam band of fiber on center of the deck, it’s the furthest point from neutral flexural axis. It will increase overall stiffness and buckling résistance of deck.

14

One of the material properties of carbon in a sandwich composite is it’s strength in tension.  Putting it on the deck (compression side) may help somewhat but the bottom is where carbon tow or strips would do the most good.

I’d lay out a straight edge, route out 2 slots in the bottom and using epoxy, install some carbon tow.  Lay some wax paper over it to smooth it down as it cures.  

If it’s a light EPS core, it will still flex but that should stiffen it somewhat.  Add more slots/carbon if needed.  By putting the slots in the right place, you could fine tune your flex pattern to allow more or less flex in specific areas of the board.

 

 

15

I put a strip 300mm wide along the deck of a long board. So stiff it is almost flexless! Too stiff to be honest. Carbon is good in compression as well as tension. A layer on the bottom is good too. The rails are far too much trouble.

16

Adding a Fake stringer (routed 1 or 2 cm deep) also adds a lot of stiffness.

This way you don’t need to cut the whole board in half to add a stringer.

It can also look very nice if you rout in a strip of wood horizontally instead of vertically like a fake stringer.

Fake stringers add more strength and stiffness than most people think, they especially increase the buckling resistance of a board!

17

Lemat is right about the longest distance to neutral gives most stifness, so adding to the center is most effective. (basic material mechanics)

However, stiffening the center without stringer support increases the chances of buckling.

Therefore stiffening the rails would be a safer bet here if you’re not adding a fake stringer.

My approach would be routing a fake stringer in the deck. If still to flexy, I would add UD-glass tape on top of it (Carbon is not worth the price IMO). The fake stringer will support the UD-glass against buckling.

18

Hans i wouldn’t call this a “fake” but an effective stringer…

19

I don’t understand why people make boards without stringers. What’s the advantage?

20

To see what happens lol
Carbon tape is cheap have at it.