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Shockwave core #224590
11/24/10 09:32 AM
11/24/10 09:32 AM
Joined: Nov 2010
Posts: 3
S
shockwave Offline OP
stranger
shockwave  Offline OP
stranger
S

Joined: Nov 2010
Posts: 3
Hello,

F18 rules

D.3 HULL SHELLS
D.3.1 MATERIALS
(a) The hull shells shall be built from polyester or vinylester resin, glass
fibres, core of PVC or balsa or felt. The combination of wood-epoxy,
injected plastic, which shall not be altered, other than locally for fittings,
and passage of equipment and normal reinforcement. Epoxy glue is
permitted for joining components. Every material that is not expressly
permitted is prohibited.

Since the world there's some rumorous about shockwave..

Shockwave core is Corecell.
Corecell isn't PVC or balsa or felt
So Corecell is prohibited in F18 rules.
Corecell marketing is that it is a better alternative to PVC.


World Council will discuss it in December.
But racers and members of F18 associations aren't aware of that.
It is an important matter, It is not normal that it stays in the secret of the Class dinosaurs.

What are you thinking about ?

Me : It's cheat, and cheat musn't be present in F18, hulls with Corecell musn't be race in F18.

-- Have You Seen This? --
Re: Shockwave core [Re: shockwave] #224592
11/24/10 10:47 AM
11/24/10 10:47 AM
Joined: Jun 2001
Posts: 3,293
Long Beach, California
John Williams Offline
Carpal Tunnel
John Williams  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 3,293
Long Beach, California
What a troll. Anonymously register today just to post that?

The Technical Committee has already addressed the issue and made recommendation to Council for next month's meeting in Paris. You can rest assured that the Council has the health of the Class, fairness, and the current Shockwave owners' concerns in mind. I expect a good and balanced outcome.


John Williams

- The harder you practice, the luckier you get -
Gary Player, pro golfer

After watching Lionel Messi play, I realize I need to sail harder.
Re: Shockwave core [Re: John Williams] #224593
11/24/10 12:32 PM
11/24/10 12:32 PM
Joined: Jul 2007
Posts: 976
France
pepin Offline
old hand
pepin  Offline
old hand

Joined: Jul 2007
Posts: 976
France
Correct behavior would be to protest all the Shockwave present at a race you're in. Not post anonymously.

You'll probably win the protest. And lose some friends!

Re: Shockwave core [Re: pepin] #224595
11/24/10 03:54 PM
11/24/10 03:54 PM

S
Scarecrow
Unregistered
Scarecrow
Unregistered
S



Guessing at the solution...

Assuming this effects all shockwaves and not a couple of "specials"

1. Grandfather existing boats (you can guarantee most the sailors don't know they were cheating).
2. Remove builder's right to self certify
3. Ban all unsold/unfinished boats from F18 class events.


Re: Shockwave core [Re: ] #224614
11/25/10 03:28 PM
11/25/10 03:28 PM
Joined: Sep 2004
Posts: 2,584
+31NL
Tony_F18 Offline
Carpal Tunnel
Tony_F18  Offline
Carpal Tunnel

Joined: Sep 2004
Posts: 2,584
+31NL
I've known about this since the worlds, but honestly, who cares?
As long as the new boats ard built according to the rules I dont see the big deal, it is not as if its owners are deliberatly breaking the rules or anything.

We dont even know how much of the material is involved, it could be just the boards or something.

What bothers me more is cowards who create accounts just to post sh1t about the class!

Re: Shockwave core [Re: Tony_F18] #224618
11/25/10 05:38 PM
11/25/10 05:38 PM
Joined: Jul 2001
Posts: 894
Branford, CT
rhodysail Offline
old hand
rhodysail  Offline
old hand

Joined: Jul 2001
Posts: 894
Branford, CT
Sounds like the builder should have their license revoked. How many of these boats are out there?

Re: Shockwave core [Re: shockwave] #224619
11/25/10 06:35 PM
11/25/10 06:35 PM
Joined: Feb 2007
Posts: 266
UK
Cheshirecatman Offline
enthusiast
Cheshirecatman  Offline
enthusiast

Joined: Feb 2007
Posts: 266
UK
Originally Posted by shockwave


Shockwave core is Corecell.
Corecell isn't PVC or balsa or felt
So Corecell is prohibited in F18 rules.
Corecell marketing is that it is a better alternative to PVC.



Shockwave, would you care to enlighten us as to which corecell foam you refer to and what that foam is made of?

The corecell literature for the A-foam refers to it being better than two forms of PVC foam. Can you confirm that this foam is not just another PVC variant?

Cheshirecatman

Re: Shockwave core [Re: Cheshirecatman] #224627
11/26/10 01:17 AM
11/26/10 01:17 AM

S
Scarecrow
Unregistered
Scarecrow
Unregistered
S



My chemistry isn't good enough to expain the difference between PVC foam and Corecell (SAN foam). The advantage of corecell is basically that it has higher elongation to failure figures which means it will withstand impacts and damage better. It also can be very easily heat shaped allowing for a closer fit to the hull and therefore less resin or bog in the structure. Given all F18s are heavy the only real advantage with corecell is its "ruggedness" A brand new boat with PVC or SAN foams will be very similar. But if you're looking at 5 year old second hand boats in 4 years time the odds are the Shockwave will be in better nick. In the early 90s when the F18 rule was written SAN foams where more much expensive, this it less so these days. As I stated above there is no reason to kick the corecell boats out of the fleet. Just make sure no more are built.

Last edited by Scarecrow; 11/26/10 01:19 AM.
Re: Shockwave core [Re: ] #224628
11/26/10 03:59 AM
11/26/10 03:59 AM
Joined: Nov 2010
Posts: 3
S
shockwave Offline OP
stranger
shockwave  Offline OP
stranger
S

Joined: Nov 2010
Posts: 3
Originally Posted by Scarecrow
therefore less resin or bog in the structure.


Mater is here

With corecell it's possible to build hulls with a better moment of inertia.
Less weight everywhere for the same strength, at the end only add more weight on the middle.
Corecell isn't pvc.


Re: Shockwave core [Re: Cheshirecatman] #224629
11/26/10 04:15 AM
11/26/10 04:15 AM
Joined: Nov 2010
Posts: 3
S
shockwave Offline OP
stranger
shockwave  Offline OP
stranger
S

Joined: Nov 2010
Posts: 3
Originally Posted by Cheshirecatman
Originally Posted by shockwave


Shockwave core is Corecell.
Corecell isn't PVC or balsa or felt
So Corecell is prohibited in F18 rules.
Corecell marketing is that it is a better alternative to PVC.



Shockwave, would you care to enlighten us as to which corecell foam you refer to and what that foam is made of?

The corecell literature for the A-foam refers to it being better than two forms of PVC foam. Can you confirm that this foam is not just another PVC variant?

Cheshirecatman



From Corecell datasheet
It’s styrene acrylonitrile (SAN) polymer base gives it unique processing and in-service properties.

Re: Shockwave core [Re: shockwave] #224673
11/27/10 04:39 PM
11/27/10 04:39 PM
Joined: Nov 2005
Posts: 1,203
uk
TEAMVMG Offline
veteran
TEAMVMG  Offline
veteran

Joined: Nov 2005
Posts: 1,203
uk
Corecell is stronger in shear than PVC so a thicker foam can be used.
Given equal skins of lay-up on each side, thicker foam gives a stronger stiffer structure.


Paul

teamvmg.weebly.com
Re: Shockwave core [Re: TEAMVMG] #224675
11/27/10 06:42 PM
11/27/10 06:42 PM

S
Scarecrow
Unregistered
Scarecrow
Unregistered
S



75 kg/m3 Klegecell R shear strength = 1.0MPa (PVC)
80 kg/m3 Divinycells H shear strength = 1.0 MPa (PVC)
A450 Corecell (81 kg/m3) shear strength = 0.8MPa

Re: Shockwave core [Re: ] #224827
12/02/10 02:48 PM
12/02/10 02:48 PM
Joined: Nov 2002
Posts: 465
FL
sail7seas Offline
addict
sail7seas  Offline
addict

Joined: Nov 2002
Posts: 465
FL
1.Do these foams have similar compressive strength?
2.In general are these foams similar for fatigue: cyclic shear load and cyclic compression?
3.After a number of years could the foam become thinner?
4.Does cyclic loading affect the foam's adhesive (resin or epoxy) ability to adhere to the exterior skin?


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