Author Topic: Foil boards breaking from bottom lam fatigue  (Read 7972 times)

Dontsink

  • Sunset Status
  • ****
  • Posts: 283
    • View Profile
    • Email
Foil boards breaking from bottom lam fatigue
« on: April 29, 2022, 10:15:05 PM »
Lots of people doing dockstarts and prone surfing are suffering from boards getting damage from the repeated stresses.
Fom loss of rigidity to total failure.
The usual point of failure is the bottom laminate,right in front of the boxes.
This part works in compression, and a flat layer of glass or carbon is not very good at resisting compression.Foam crushes,carbon bends more and more until it fails.

Connecting the boxes to the top layer (As with the DW box wrap method) is a good way to fight this.

Some people are also using carbon arrow shafts as reinforcement for the bottom lam.
Very light,and a tubular shape resists compression way better than flat lam.
Might be worth a try.

clay

  • Teahupoo Status
  • ******
  • Posts: 1117
    • View Profile
    • www.clayisland.com
    • Email
Re: Foil boards breaking from bottom lam fatigue
« Reply #1 on: April 30, 2022, 11:31:49 AM »
I am a big fan of durable boards. 

Broken track boxes suck, and how to repair properly is a question that I would love to have a definitive answer to.  I have seen a lightweight guy go big on an air and crack the boxes on a new board.  Seems like foam of any strength is doomed to fail...

Maybe as the sport grows someone out there will have the funds to stress test various build ideas and publish the results.

For now wondering what boards have withstood the real world test and had the boxes keep going strong?  Jimmy Lewis, he's been building wind sport boards forever has anyone had track boxes fail (I still have one but only have a dozen session on it)?  Mackite raves about the durability of Fanatic?

Are the wind sport brands ahead here and have the construction stronger than the surf board shapers?

I put one of Blue Planet's strong boxes in and it seemed bomb proof, but sold the board before I got the chance to long term test it.

Aloha, I welcome and appreciate all responses of positivity and good feeling.

YouTube: https://www.youtube.com/channel/UCOIE6FWr1SpWvbPJIIiEgog

PonoBill

  • Cortez Bank Status
  • *****
  • Posts: 25461
    • View Profile
Re: Foil boards breaking from bottom lam fatigue
« Reply #2 on: April 30, 2022, 01:05:37 PM »
Strength + weight + cost = X

Mark Raaphorst told me recently that Tuttle boxes seem to be making a comeback. The primary design issue with tracks is that with the originally intended mounting design they offer very little strength. It's up to the board builder to decide how to overcome that and make them strong enough. I suppose a board builder could make a weak tuttle mount, but they'd have to work at it. Anything tied through the board to both top and bottom is going to have a fair amount of beam strength, even in typical surfboard construction. It's pretty easy to make a super-strong Tuttle that's still fairly light. It's more difficult and more expensive to make a super-strong track box.

It's also a lot more difficult to make a light, strong, rigid carbon mast with a track mount. With a tuttle mount the carbon runs in a straight line, from fuselage to board, and the entire mount is inside the board and tuttle box.

I think the next custom board I order or build will have a Tuttle. I never really mess with mast position anyway. I don't use straps, so I don't really need adjustability.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

EastCoastFoiler

  • Waikiki Status
  • *
  • Posts: 41
    • View Profile
Re: Foil boards breaking from bottom lam fatigue
« Reply #3 on: April 30, 2022, 01:51:10 PM »
My boards these days are solid divinycell with pilar boxes connecting deck and bottom.  I’m 220 lbs, hard pumper, run aground frequently at speed.  No issues with my boards.  Production stuff lasts less than 2 weeks in my hands.

PonoBill

  • Cortez Bank Status
  • *****
  • Posts: 25461
    • View Profile
Re: Foil boards breaking from bottom lam fatigue
« Reply #4 on: April 30, 2022, 09:17:21 PM »
do you wrap the divinycell with carbon or anything?
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

EastCoastFoiler

  • Waikiki Status
  • *
  • Posts: 41
    • View Profile
Re: Foil boards breaking from bottom lam fatigue
« Reply #5 on: May 01, 2022, 02:36:48 AM »
Oho yea.  2x 6oz. Carbon  Plus a box patch under vacuum. Standard foil glassing.

Califoilia

  • Axis Demo Rep
  • Teahupoo Status
  • ******
  • Posts: 1488
  • San Clemente
    • View Profile
    • Email
Re: Foil boards breaking from bottom lam fatigue
« Reply #6 on: May 01, 2022, 12:51:09 PM »
DISCLAIMER: I'm going to preface this by saying that the board to be pictured below is over a year old, and the manufacturer is now using a completely different method to install boxes.

That said, this board was brought in for it "leaking where the red arrow is pointing" (just to the right of the blade guard), and no other apparent damage....


Upon opening, this was found....

Everything seemed to be intact; foam a little waterlogged, but not crushed. Although...

Further inspection with some poking, pushing, and prodding this was discovered...

A complete break of the one box, and the Divinycell obviously cracked that can be seen in the above pic when you look closer now knowing that it's there.

Talking to the owner, he didn't remember hitting anything, but obviously something hit something to cause that kind of damage to the box.

So right now, I'm of the opinion that - outside of the Chinook boxes that I've not seen used in person yet, but they look beefy and impressive - we've yet to see boxes made specifically for the rigors and stresses put on them in foiling applications.

I've used the dual stinger method (w/o any HD foam) gluing the entire length of the boxes to the stingers that run from tail to just shy of the middle of the board for 5+ years now, and have never had any breakage or delam, and have smacked a bottom or two with them over the quite a few years of foiling in way further than I know I should be.

But I'm also not saying that that's the ultimate answer or solution, and that there just might be a touch of good luck to go along with that install method.
« Last Edit: May 01, 2022, 12:53:35 PM by Califoilia »
Me: 6'1"/185...5'1" Kings Foil Board...5'4" Kings Wing Board...9'6" Bob Pearson "Laird Noserider"...14' Lahui Kai "Manta"...8'0" WaveStorm if/when the proning urges still hit.

supmmmm

  • Rincon Status
  • ***
  • Posts: 125
    • View Profile
Re: Foil boards breaking from bottom lam fatigue
« Reply #7 on: May 01, 2022, 01:14:41 PM »
Interesting - I’ve hit the reef once and sand bar a couple of times already - no issues with my board so far.
To Bill’s point - wonder if a longer Tuttle would allow for a more solid mount while still allowing fore and aft mast adjustments?

finbox

  • Waikiki Status
  • *
  • Posts: 38
    • View Profile
Re: Foil boards breaking from bottom lam fatigue
« Reply #8 on: May 01, 2022, 03:00:55 PM »
Here is a photo of a prone board that was used in the surf and learning to pump. The box was leaking from the front edge. The skin had delaminated from the box, causing the leak. On further investigation the box could move up & down. So, major surgery & a fix. The divini cell was broken and just lifted out.
On boards & pumping - it seems alot of boards were broken at San O 2 years ago from pumping. One big guy seemed to go thru a board per week until the board builder got it right. I think it was wood stringers.

Dontsink

  • Sunset Status
  • ****
  • Posts: 283
    • View Profile
    • Email
Re: Foil boards breaking from bottom lam fatigue
« Reply #9 on: May 01, 2022, 10:42:55 PM »
I am using dual stringers on this dockstart mini board.No box rails because the foil will always be at the back it being so small.Hope it holds together,it is my first full "build" :)

EastCoastFoiler

  • Waikiki Status
  • *
  • Posts: 41
    • View Profile
Re: Foil boards breaking from bottom lam fatigue
« Reply #10 on: May 02, 2022, 06:28:52 AM »
@Dontsink

Its going to be too thinn.  My last board i went from a 3" board to 2" and beefed up the construction and it still wasn't stiff enough  -  Stiffness is thickness sqared - provided there's a good connection between the 2 sides.   

For a given layup a 1" board is going to have 4X the flex of a 2" board and 9X the flex of a 3" board.  The reason kiters can get away with those lunch trays is they're not relying on pumping for power.  I kited a 1" lunch tray for years, giving it all kinds of abuse, but as soon as i started wave kiting and brought that pump cadence to my kite foiling (pumping through tacks, sneaking extra upwind lines on waves) that board died almost immediately.

Thats not to say its not going to be strong enough - you can add that extra carbon and absorb the load but it will never be stiff as a 2" board.    Ex. Wakeboards are very strong but not stiff.

Get some divinycell - https://www.aircraftspruce.com/catalog/cmpages/divinycellfoam.php 2" 24x 48 blank would probably work but the 3" would be best.  I personally would never go thinner than 3 for something i'm going to be pumping hard.

Dontsink

  • Sunset Status
  • ****
  • Posts: 283
    • View Profile
    • Email
Re: Foil boards breaking from bottom lam fatigue
« Reply #11 on: May 02, 2022, 06:50:34 AM »
@Dontsink

Its going to be too thinn.  My last board i went from a 3" board to 2" and beefed up the construction and it still wasn't stiff enough  -  Stiffness is thickness sqared - provided there's a good connection between the 2 sides.   

For a given layup a 1" board is going to have 4X the flex of a 2" board and 9X the flex of a 3" board.  The reason kiters can get away with those lunch trays is they're not relying on pumping for power.  I kited a 1" lunch tray for years, giving it all kinds of abuse, but as soon as i started wave kiting and brought that pump cadence to my kite foiling (pumping through tacks, sneaking extra upwind lines on waves) that board died almost immediately.

Thats not to say its not going to be strong enough - you can add that extra carbon and absorb the load but it will never be stiff as a 2" board.    Ex. Wakeboards are very strong but not stiff.

Get some divinycell - https://www.aircraftspruce.com/catalog/cmpages/divinycellfoam.php 2" 24x 48 blank would probably work but the 3" would be best.  I personally would never go thinner than 3 for something i'm going to be pumping hard.

This one is 4cm= 1.5in :(
Sounds like good advice, and thanks because this one is about  ready for lam but i can still reinforce it.
Maybe two additional stringers on the inside of the boxes would be more efficient than just heaping carbon layers?.

Glass schedule will be 200g Carbon/Innegra+200g Carbon  on the top and same on bottom.
Plus usual foilbox patches and wood veneer patches where the feet land.


clay

  • Teahupoo Status
  • ******
  • Posts: 1117
    • View Profile
    • www.clayisland.com
    • Email
Re: Foil boards breaking from bottom lam fatigue
« Reply #12 on: May 02, 2022, 09:47:35 AM »
FYI - years ago tried ultra thick super burley stringers and they ended up pulling through the glass.
Aloha, I welcome and appreciate all responses of positivity and good feeling.

YouTube: https://www.youtube.com/channel/UCOIE6FWr1SpWvbPJIIiEgog

Dontsink

  • Sunset Status
  • ****
  • Posts: 283
    • View Profile
    • Email
Re: Foil boards breaking from bottom lam fatigue
« Reply #13 on: May 02, 2022, 10:24:56 AM »
FYI - years ago tried ultra thick super burley stringers and they ended up pulling through the glass.

Oh,my...was it plain glass?
The nightmare scenarios are endless.

I hope i will be safe from that with the Innegra and whatever else i slap on for reinforcement.
Goal is to keep this one around 2kg , i do want a dockstart board but it is also a great school/testbed for when i make a Wingfoil board later on.
For a +3kg dock board it is way easier to go with bent plywood and maybe some top carbon.
I has all the fiddly bits with 1/3 of the materials expense.

tarquin

  • Sunset Status
  • ****
  • Posts: 327
    • View Profile

 


* Recent Posts

post Re: Dave Daum Build Series - Foilboard Construction A to Z - Q & A
[The Shape Shack]
tarquin
Today at 12:18:13 AM
post 2020
[General Discussion]
AndrewTauSh
Today at 12:11:15 AM
post Re: Heading to Maui next week…….
[Wingsurfing, Windfoiling, Wingfoiling, Wing SUP]
PonoBill
December 03, 2022, 10:39:26 PM
post Re: Another revelation about the Barricuda style Kalama board!
[Foil SUP]
Beasho
December 03, 2022, 07:27:28 PM
post Re: Heading to Maui next week…….
[Wingsurfing, Windfoiling, Wingfoiling, Wing SUP]
JohnnyTsunami
December 03, 2022, 05:03:20 PM
post Re: New Winging specific boards from Naish.
[Wingsurfing, Windfoiling, Wingfoiling, Wing SUP]
Badger
December 03, 2022, 03:46:30 PM
post Re: Heading to Maui next week…….
[Wingsurfing, Windfoiling, Wingfoiling, Wing SUP]
John65
December 03, 2022, 02:29:42 PM
post Re: New Winging specific boards from Naish.
[Wingsurfing, Windfoiling, Wingfoiling, Wing SUP]
Solent Foiler
December 03, 2022, 02:28:42 PM
post Re: Dave Daum Build Series - Foilboard Construction A to Z - Q & A
[The Shape Shack]
JohnnyTsunami
December 03, 2022, 12:42:36 PM
post Re: Heading to Maui next week…….
[Wingsurfing, Windfoiling, Wingfoiling, Wing SUP]
PonoBill
December 03, 2022, 11:49:32 AM
post Heading to Maui next week…….
[Wingsurfing, Windfoiling, Wingfoiling, Wing SUP]
John65
December 03, 2022, 10:50:56 AM
post Re: Blue Planet Show- Wing Foil interviews
[Wingsurfing, Windfoiling, Wingfoiling, Wing SUP]
blueplanetsurf
December 03, 2022, 10:26:35 AM
post Re: One Fine Day
[Random]
daswusup
December 03, 2022, 06:28:05 AM
post Re: Plastic Buckles
[Wingsurfing, Windfoiling, Wingfoiling, Wing SUP]
tj_boof
December 03, 2022, 05:08:14 AM
post Re: Something new?
[Foil SUP]
tarquin
December 03, 2022, 04:21:38 AM
SimplePortal 2.3.7 © 2008-2022, SimplePortal