I’m a long time browser of this forum, and I hope you guys can help me with a crack in my new board.
The board is a 5’11" with a stinger just lower than the mid-point (1" cut-away in the rail), and I managed to get a small crack at each stinger. Each crack is a couple of inches long and spans over the sharp edge of the rail about 0.5-1cm up the rail at the stinger. Here are some pics to give you an idea of the crack:
My question is, seeing the stinger creates a new structural element that I am not familiar with, is it worth getting a full-bown ding-repair for these cracks? and if yes, what type of repair would be the best?
Also, seeing as the crack is not only on the bottom of the board but also about 0.5-1cm up the rail, will it be risky to surf it until its fixed?
Its an awesome board, so I would hate to break it or give it a short life…
Happy to hear everyones opinion. My shaper is away on holidays, so thought I would ask everyone here too
That crack is starting at that point because of the stinger...that sudden change in continuity of the board's flex under stress will become a weak point. Hence the cracks, and now you have a starting point for a break next time you get slammed.
I've seen creases and snaps begin with less than that.
I suggest you get it fixed, even with a reinforcing section of extra glass much bigger than the ding, if you want some peace of mind.
yep, exactly like Josh said, what you have happening here is something like what's called a 'notch fracture' in steel structures, the abrupt transition of how the board's width changes makes for ...ahmmmmm...two very different flexes with no real transitional thing going on between them. It's why you see most stingers done with more bevel or foiling at the transition, say like http://www.surfresearch.com.au/00000039.html , where the sting is more like a wing coming off a simple curved outline shape.
Not that you've chosen a bad way, just that you need to make the transitional area at the stingers stronger, so it'll flex together rather than having that structural abrupt notch.
And, again as Josh says, I'd add glass bridging that transition point, both top and bottom. I think you could do worse than a band 8-12" wide, 6 oz cloth, centered on the stinger. Single layer on the bottom, double on the deck with maybe an 8" band and a 12" band over it. Do it with slow batches of resin, both so the resin is tougher and so that you have time to form the cloth smoothly around the stingers without cutting it as you'd cut cloth at the nose of a board, y'know? Just the same way as you'd fix a buckled or snapped board. Feather the edges of the bands before you hotcoat it, so you don't have two new abrupt transitions, plus then it will look more blended.
It appears to be terminal in nature. Repair is certainly called for, and it will buy you some time, but failure at that location is inevitable. The ''notch'' in the outline, as pointed out, is too severe. Flex will always seek out, and exploit any design flaw.
The problem is also referred to in biomechanics as a ‘stess riser’ which occurs where there is an abrupt change in flex characteristics of a material. The material will fracture at the site of the transition. If you are committed to using the board, you can apply something to the deck to strengthen the transition area. For example, take some fin rope and make a series of parallel, longitudinally oriented ridges across the area and continue down into the tail then cover with a layer of cloth. May look funky with the ridges on the deck but could diffuse the stress riser enough to prevent further cracking.
Doc and the others are 100% correct. That rail profile is totally wrong for a sting outline. Too steep, boxy, and abrupt. One of the down sides of the recent trend to recycle “retro” designs. Many people who attempt a modernized version cannot grasp the way all elements must fit together. Witness all the fake, mis-named, pseudo fish out there.
It surfs amazingly well. All of the benefits of forward planing area and volume, added with the benefits of a tight pulled in tail and quad fins. Its a great ride, worth saving! I’ll just head out and get it well reinforced so it can withstand another pounding.
I’m pretty sure that it happened when landing a floater with the lip, with the force of me falling added to the force of the lip exploding up at me. I was surprised it didn’t do worse actually…
Took it to the ding repair man. He thought it was pretty minor, only a superficial crack thats not all the way through. He reluctantly agreed to reinforce the section with some glass but thought it was unecessary. It’ll be surfing on it in days
