|
|
13-06-2011, 16:49
|
#31
|
always in motion is the future
Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 18,870
|
Re: Noticed Another BIGGER Crack !
Quote:
Originally Posted by E.L.Green
when the shrouds were loose, it was sending a shockload to the rigging, especially when gybing which is why i felt the need to retune the rig, there is minimal play in the leeward shrouds now..
|
play in leeward shrouds indicates lack of pre-tension.
I'll repeat this once again: it doesn't matter -when- this damage occurred, only -the cause- is important. It might well have been lack of rig tension and shockloads, but The rig is the cause. The only important thing now is that you have this damage which has (severely) weakened the construction and you must fix that. Tuning the rig correctly doesn't fix this damage; it prevents it from happening again at most.
Ignore statements that say that knee isn't constructional; the only reason for having knees is constructional strength.
ciao!
Nick.
|
|
|
13-06-2011, 17:16
|
#32
|
Registered User
Join Date: Apr 2011
Location: Geelong Australia
Boat: Beneteau First 44.7
Posts: 68
|
Re: Noticed Another BIGGER Crack !
Quote:
Originally Posted by E.L.Green
im certain these were there before the smaller crack i found i just wasnt paying attention but now im somewhat more concerned. i had her under full sail in steady winds and it didnt open or pinch shut on either tack and i want to fix it, but my concern is was this due to flexing? i took a poke with a knife and found that it is just the spray liner, the only thing behind the liner is foam from what i can see. i just dont know if this is something that should not be sailed with or just cosmetic? i tuned my rig to the specs of Schock themselves via the owner Tom over the phone but it still worries me !
Attachment 28293
Attachment 28294
|
Looks to me like a plywood hanging locker- not a structural component. Has someone fallen on or pushed the locker opening up the crack? If it was a structural issue caused by rig tension then the cabin side will not have bent and a similar crack should be found along the whole of the cabin as the whole cabin will have lifted and the deck flexed.
|
|
|
13-06-2011, 18:15
|
#33
|
always in motion is the future
Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 18,870
|
Re: Noticed Another BIGGER Crack !
Quote:
Originally Posted by frant
Looks to me like a plywood hanging locker- not a structural component.
|
- there's 2 cracks at different places
- a boat isn't a house. If you remove a hanging locker from a house you just moved a piece of furniture. This isn't how it works on a boat.
ciao!
Nick.
|
|
|
13-06-2011, 23:01
|
#34
|
Registered User
Join Date: Apr 2011
Location: Geelong Australia
Boat: Beneteau First 44.7
Posts: 68
|
Re: Noticed Another BIGGER Crack !
Quote:
Originally Posted by s/v Jedi
- there's 2 cracks at different places
- a boat isn't a house. If you remove a hanging locker from a house you just moved a piece of furniture. This isn't how it works on a boat.
ciao!
Nick.
|
Yes but maybe the cracks appeared because the little plywood hanging locker is not a structural component, certainly not designed to support the chainplate loading. Of course it will crack at the join if you lean on it or bump it. I think that you can safely ignore the crack and enjoy sailing.
|
|
|
14-06-2011, 08:02
|
#35
|
always in motion is the future
Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 18,870
|
Re: Noticed Another BIGGER Crack !
Quote:
Originally Posted by frant
Yes but maybe the cracks appeared because the little plywood hanging locker is not a structural component, certainly not designed to support the chainplate loading. Of course it will crack at the join if you lean on it or bump it. I think that you can safely ignore the crack and enjoy sailing.
|
I think, you think, we all think. The problem is that the owner of this boat isn't helped by us thinking when he gets more damage by not fixing the damage that is already done.
If these cracks are meant to be there, the builder would have put them there. You don't have to be an engineer to understand that damage must be fixed.
ciao!
Nick.
|
|
|
14-06-2011, 09:30
|
#36
|
Armchair Bucketeer
Join Date: Oct 2006
Posts: 10,012
|
Re: Noticed Another BIGGER Crack !
OP appears to have decided on the answer he wants to hear
A lesson for boat buyers - beware the PO
|
|
|
14-06-2011, 15:47
|
#37
|
Registered User
Join Date: Apr 2011
Location: Geelong Australia
Boat: Beneteau First 44.7
Posts: 68
|
Re: Noticed Another BIGGER Crack !
Quote:
Originally Posted by s/v Jedi
I think, you think, we all think. The problem is that the owner of this boat isn't helped by us thinking when he gets more damage by not fixing the damage that is already done.
If these cracks are meant to be there, the builder would have put them there. You don't have to be an engineer to understand that damage must be fixed.
ciao!
Nick.
|
So you fill the crack up with a flexible compound for a cosmetic repair. If that thin plywood sheet hanging from under the deck is a major structural component then sure it should be repaired. If it is not then you are just causing unnecessary concern to the OP. IMHO a plywood sheet effectively edge glued to the underside of the deck liner has never been a structural component, particularly for tensile stresses from the rig. Its up to the OP what he does but I wouldn't be concerned about a cosmetic crack in a 20 year old boats furniture.
|
|
|
14-06-2011, 18:08
|
#38
|
Registered User
Join Date: Feb 2009
Location: A real life Zombie from FL
Boat: Gulfstar 53 - Osiris
Posts: 5,416
|
Re: Noticed Another BIGGER Crack !
Quote:
Originally Posted by frant
. . . IMHO a plywood sheet effectively edge glued to the underside of the deck liner has never been a structural component, particularly for tensile stresses from the rig. . . .
|
IMHO, it is good policy to "never say never" as I have seen over the years some rather strange and unusual construction/design situations especially on smaller day-sailors.
- - But it is true that we do not know what that vertical bulkhead is - structural or just part of a locker. But I have seen structural bulkheads "tabbed" to the hull and cabin top, so unless the OP can provide more details, we are just whistling in the dark on this one.
|
|
|
14-06-2011, 21:06
|
#39
|
always in motion is the future
Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 18,870
|
Re: Noticed Another BIGGER Crack !
Quote:
Originally Posted by frant
So you fill the crack up with a flexible compound for a cosmetic repair. If that thin plywood sheet hanging from under the deck is a major structural component then sure it should be repaired. If it is not then you are just causing unnecessary concern to the OP. IMHO a plywood sheet effectively edge glued to the underside of the deck liner has never been a structural component, particularly for tensile stresses from the rig. Its up to the OP what he does but I wouldn't be concerned about a cosmetic crack in a 20 year old boats furniture.
|
How do you know it's "edge glued to the liner" and not tabbed with glass to hull and deck? If it is attached to both the hull and the underside of the deck and the builder put it there, it is structural. FYI: plywood sheet is a very structural material.
I never wrote anything about doing a cosmetic repair with flexible compound... please quote me if you think different. I have not recommended method of repair because others already did so and I agreed with what they wrote (structural repair).
ciao!
Nick.
|
|
|
14-06-2011, 21:41
|
#40
|
Registered User
Join Date: Mar 2007
Location: Santa Cruz
Boat: SAnta Cruz 27
Posts: 6,711
|
Re: Noticed Another BIGGER Crack !
There aren't enough pictures to decide for sure, but I'm with Osiris on this one. The crack shows that there isn't enough structure to take the sail loads.
I don't think that fiberglass tabbing would take the load--it will pull away from the overhead. My first attempt at reinforcing things might be to take stainless L-straps on either side of the vertical bulkhead and through-bolt them through the vertical bulkhead and the overhead. If you can't get to the back of the overhead to through bolt, its time to try something else. If Schock stonewalls you, I'd talk to a good shipwright.
|
|
|
14-06-2011, 21:56
|
#41
|
Registered User
Join Date: Apr 2011
Location: Geelong Australia
Boat: Beneteau First 44.7
Posts: 68
|
Re: Noticed Another BIGGER Crack !
Well I am going to stick with my opinion that the OP has a bit of plywood interior joinery that has become detached-not a structural member that was ever designed to take rigging loads. If that was the case then the original builder has done a mighty shonky job. Have a look at the photo's its a thin bit of plywood cabinet tabbed to the underside of the deck to hold it in place. No way is that construction or material suggestive of a bulkhead designed to support rigging loads. The engineering simply says don't worry about it. My suggestion was for a cosmetic filler if the appearance of the crack bothers the OP. Nothing else is required (in my opinion!)
|
|
|
15-06-2011, 06:19
|
#42
|
Registered User
Join Date: Jul 2010
Location: lavallette New Jersey
Boat: Santana 2023 - Impulsive II
Posts: 174
|
Re: Noticed Another BIGGER Crack !
two members of Schock contacted me on another forum and this is the result..
WDSchock
Member
Join Date: Apr 2011
Posts: 90
Rep Power: 1
Good - Tom is traveling and out of reach of contact; we at the factory were trying to understand what could possibly the root cause.
__________________
Builders of the Schock, Santana, Lido, Sabot, and Harbor line of sailboats
tomschock
Junior Member
Join Date: Sep 2009
Posts: 1
Rep Power: 0
Although this crack has been there for some time and doesn't seem to be getting any worse, I would recommend that it be repaired. You will need to clean away the paint and fractured glass. Then patch the area by filling the crack with epoxy putty. Then put fiberglass cloth over the area. Once it is dry, you can sand it and paint it. Tom Schock
|
|
|
15-06-2011, 13:09
|
#43
|
always in motion is the future
Join Date: Feb 2009
Location: in paradise
Boat: Sundeer 64
Posts: 18,870
|
Re: Noticed Another BIGGER Crack !
Quote:
Originally Posted by E.L.Green
Although this crack has been there for some time and doesn't seem to be getting any worse, I would recommend that it be repaired. You will need to clean away the paint and fractured glass. Then patch the area by filling the crack with epoxy putty. Then put fiberglass cloth over the area. Once it is dry, you can sand it and paint it. Tom Schock
|
Thank you, finally sensible info.
watch and learn frant
ciao!
Nick.
|
|
|
15-06-2011, 13:45
|
#44
|
Registered User
Join Date: Aug 2008
Location: Depends
Boat: Cabo Rico
Posts: 770
|
Re: Noticed Another BIGGER Crack !
Interesting thread on Morris boats over at SN where Mr Schock is questioning their value and saying they aren't built well enough to justify their price. He is taking some heat for his comments.
|
|
|
15-06-2011, 13:48
|
#45
|
Moderator Emeritus
Join Date: Aug 2005
Location: Carlsbad, CA
Boat: 1976 Sabre 28-2
Posts: 7,505
|
Re: Noticed Another BIGGER Crack !
If that piece of plywood is actually structural, tabbing it to the deck isn't going to do any good as it will probably just pull away again. After the fact fiberglass tabbing just doesn't hold well in tension. Probably, even using epoxy resin won't stick if there is much tension on the cabin side. If it is structural, and I doubt that it is, you'll need to through bolt a piece of metal angle, either aluminum or stainless and through bolt it to the deck and plywood. That way, the deck isn't going to go anywhere without taking the plywood along with it.
If the mast is keel stepped adding a tie rod from the mast to the cabin top might solve your problem With a keel stepped mast, loads on the mast try and drive the mast through the bottom of the boat and pull the chainplates up through the deck. That puts inward pressure on the hull which pinches the deck inward in in the area of the mast. Since the deck isn't secured to the mast, the deck tends to lift. Most boats with a keel stepped mast that are pushed hard have a tie rod or cable from the cabin top to the mast to keep the cabin from lifting at the mast. It's usually just a padeye on the cabin top in line with the mast and another one somewhere down the mast. The two padeyes are connected by a short piece of 1x19 wire or rod with a turnbuckle to tension it. Voila, no more deck movement.
__________________
Peter O.
'Ae'a, Pearson 35
'Ms American Pie', Sabre 28 Mark II
|
|
|
|
|
Thread Tools |
Search this Thread |
|
|
Display Modes |
Rate This Thread |
Linear Mode
|
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
|
Advertise Here
Recent Discussions |
|
|
|
|
|
|
|
|
|
|
|
|
Vendor Spotlight |
|
|
|
|