Hi all.Maybe it's just me..Last year I had the "mast support" bulkheads re-fixed to the flanges at the inside of the hull with heavier bolts.In the Spring I fitted a beefed-up mast support beam as the old one was slipping.The new one is about 4-5cm thick and backed by Steve Birch's stainless plate is very strong.The problem is that my problems now seem to have moved to the bulkheads.They have both "bulged" or bowed out of plane by say 4mm (1/4 inch) close to the top.Obviously not much but it ain't going to get any better.I'm getting a guy who has a very good reputation for structural work to have a look tomorrow.Should I ask him to double up the bulkhead thickness as a friend suggested (fab up copies in marine ply and bolt them through)?It seems the obvious solution???Or should I consider a mast support post that takes the load down to a shoe on top of the keel.Apart from the resulting difficulty in getting into the forecabin, are there any other reasons not to go for this option?If I did go for a mast support post, are the two "mast support" bulkheads now redundant (I could replace them by curtains for privacy)? If they were not needed, some adjustment could be made to the shelf outside the portside hanging locker to improve access to the forecabin if I went for the mast support post option.Did I read here that the false floor in the saloon below the mast (where the post would go) has a structural purpose and that cutting it to allow a post to pas through to a shoe atop the keel would weaken the structure?Thanks,John V1447 Breakaway
More Bulkhead Blues
- Thread starter Vega1447
- Start date
Hey John - I would try to find the reason for the bulkhead deflection before doing anything further (e.g. are the originals rotten or are the shrouds too tight - did the bulkheads get damaged when you did the recent work to reinforce them etc). The bulkheads do more than simply support the deck under the mast - removing them would be a mistake, IMHO. Trev (Mystic Rose - V2915)Sent from my “contract free” BlackBerry® smartphone on the WIND network.From: "John.Kinsella@... [AlbinVega]" <AlbinVega@yahoogroups.com>
Sender: AlbinVega@yahoogroups.com
Date: Tue, 19 Aug 2014 09:21:58 -0700To: <AlbinVega@yahoogroups.com>ReplyTo: AlbinVega@yahoogroups.com
Subject: [AlbinVega] More Bulkhead Blues
Hi all.Maybe it\'s just me..Last year I had the "mast support" bulkheads re-fixed to the flanges at the inside of the hull with heavier bolts.In the Spring I fitted a beefed-up mast support beam as the old one was slipping.The new one is about 4-5cm thick and backed by Steve Birch\'s stainless plate is very strong.The problem is that my problems now seem to have moved to the bulkheads.They have both "bulged" or bowed out of plane by say 4mm (1/4 inch) close to the top.Obviously not much but it ain\'t going to get any better.I\'m getting a guy who has a very good reputation for structural work to have a look tomorrow.Should I ask him to double up the bulkhead thickness as a friend suggested (fab up copies in marine ply and bolt them through)?It seems the obvious solution???Or should I consider a mast support post that takes the load down to a shoe on top of the keel.Apart from the resulting difficulty in getting into the forecabin, are there any other reasons not to go for this option?If I did go for a mast support post, are the two "mast support" bulkheads now redundant (I could replace them by curtains for privacy)? If they were not needed, some adjustment could be made to the shelf outside the portside hanging locker to improve access to the forecabin if I went for the mast support post option.Did I read here that the false floor in the saloon below the mast (where the post would go) has a structural purpose and that cutting it to allow a post to pas through to a shoe atop the keel would weaken the structure?Thanks,John V1447 Breakaway
Sender: AlbinVega@yahoogroups.com
Date: Tue, 19 Aug 2014 09:21:58 -0700To: <AlbinVega@yahoogroups.com>ReplyTo: AlbinVega@yahoogroups.com
Subject: [AlbinVega] More Bulkhead Blues
Hi all.Maybe it\'s just me..Last year I had the "mast support" bulkheads re-fixed to the flanges at the inside of the hull with heavier bolts.In the Spring I fitted a beefed-up mast support beam as the old one was slipping.The new one is about 4-5cm thick and backed by Steve Birch\'s stainless plate is very strong.The problem is that my problems now seem to have moved to the bulkheads.They have both "bulged" or bowed out of plane by say 4mm (1/4 inch) close to the top.Obviously not much but it ain\'t going to get any better.I\'m getting a guy who has a very good reputation for structural work to have a look tomorrow.Should I ask him to double up the bulkhead thickness as a friend suggested (fab up copies in marine ply and bolt them through)?It seems the obvious solution???Or should I consider a mast support post that takes the load down to a shoe on top of the keel.Apart from the resulting difficulty in getting into the forecabin, are there any other reasons not to go for this option?If I did go for a mast support post, are the two "mast support" bulkheads now redundant (I could replace them by curtains for privacy)? If they were not needed, some adjustment could be made to the shelf outside the portside hanging locker to improve access to the forecabin if I went for the mast support post option.Did I read here that the false floor in the saloon below the mast (where the post would go) has a structural purpose and that cutting it to allow a post to pas through to a shoe atop the keel would weaken the structure?Thanks,John V1447 Breakaway
Larry- I too have some separation in the ply used for the bulkhead on one side of the opening between v-berth and salon. The header (on my series one) and side support boards from top to keel are straight and true. I think I may have had some water get through by the mast that delaminated a small area of bulkhead plywood. I believe the leak is fixed and I am going to sandwich the delaminated ply with good ply and glue/bolt together.Sent from my iPad
Thanks Larry, Trevor & all for replies.
The local structural expert spend an hour poking around and his
advice was that there was no risk of "catastrophic failure"... and
that there was no need to strengthen the structure.
He didn't think that any strengthening of the bulkheads was
necessary but advised that either "doubling up" the existing
bulkheads or (neater idea I think) building an arch by installing
struts (say 1ft wide) running diagonally from top inboard of each
bulkhead outboard and down to a wooden shoe glassed to the inside
of underwater hull would greatly strengthen the structure. The
struts would be through-bolted and glued to the two existing
bulkheads.
I may investigate getting the latter done over the winter..
Larry: I'll post pics this weekend after I visit boat..
John V1447 Breakaway
On 20/08/14 00:34, Larry Wills
lewills30@... [AlbinVega] wrote:
The local structural expert spend an hour poking around and his
advice was that there was no risk of "catastrophic failure"... and
that there was no need to strengthen the structure.
He didn't think that any strengthening of the bulkheads was
necessary but advised that either "doubling up" the existing
bulkheads or (neater idea I think) building an arch by installing
struts (say 1ft wide) running diagonally from top inboard of each
bulkhead outboard and down to a wooden shoe glassed to the inside
of underwater hull would greatly strengthen the structure. The
struts would be through-bolted and glued to the two existing
bulkheads.
I may investigate getting the latter done over the winter..
Larry: I'll post pics this weekend after I visit boat..
John V1447 Breakaway
On 20/08/14 00:34, Larry Wills
lewills30@... [AlbinVega] wrote:
Sounds like your structural expert is on top of transferring loads to help with any deflection not only in the deck but the hull itself. Sounds like good advice, so good to hear…because that is exactly what I have done to my boat…lol. LarrySent from Windows MailFrom: n4lbl alan.schulman@... [AlbinVega]Sent: Thursday, August 21, 2014 2:15 AMTo: n4lbl alan.schulman@... [AlbinVega]
Thanks Larry, Trevor & all for replies.
The local structural expert spend an hour poking around and his
advice was that there was no risk of "catastrophic failure"... and
that there was no need to strengthen the structure.
He didn\'t think that any strengthening of the bulkheads was
necessary but advised that either "doubling up" the existing
bulkheads or (neater idea I think) building an arch by installing
struts (say 1ft wide) running diagonally from top inboard of each
bulkhead outboard and down to a wooden shoe glassed to the inside
of underwater hull would greatly strengthen the structure. The
struts would be through-bolted and glued to the two existing
bulkheads.
I may investigate getting the latter done over the winter..
Larry: I\'ll post pics this weekend after I visit boat..
John V1447 Breakaway
On 20/08/14 00:34, Larry Wills
lewills30@... [AlbinVega] wrote:
Thanks Larry, Trevor & all for replies.
The local structural expert spend an hour poking around and his
advice was that there was no risk of "catastrophic failure"... and
that there was no need to strengthen the structure.
He didn\'t think that any strengthening of the bulkheads was
necessary but advised that either "doubling up" the existing
bulkheads or (neater idea I think) building an arch by installing
struts (say 1ft wide) running diagonally from top inboard of each
bulkhead outboard and down to a wooden shoe glassed to the inside
of underwater hull would greatly strengthen the structure. The
struts would be through-bolted and glued to the two existing
bulkheads.
I may investigate getting the latter done over the winter..
Larry: I\'ll post pics this weekend after I visit boat..
John V1447 Breakaway
On 20/08/14 00:34, Larry Wills
lewills30@... [AlbinVega] wrote:
Hi Larry & all.See Album: Breakaway Bulkheads Album: Breakaway Bulkheads Breakaway Bulkheads Up DirectView SideView-2 SideView Generated by album
from MarginalHacks
on Mon Aug 25 17:31:57 2014 View on jkcray.maths.ul.ie Preview by Yahoo for 3 slightly blurry photos of starboard bulkhead.You'll need to download & rotate as appropriate.The vertical batten was fitted with the intention of stiffening he bulkhead but I think it is so light that it has very little effect.The photo DirectView suggests that the top of the vertical batten (and indeed the "doorpost" at inboard side of bulkhead is distorted to starboard/outboard at top.I didn't see this on visual inspection - I used a phone camera so maybe lens distortion.I check carefully when I go to boat again.John V1447 Breakaway
from MarginalHacks
on Mon Aug 25 17:31:57 2014 View on jkcray.maths.ul.ie Preview by Yahoo for 3 slightly blurry photos of starboard bulkhead.You'll need to download & rotate as appropriate.The vertical batten was fitted with the intention of stiffening he bulkhead but I think it is so light that it has very little effect.The photo DirectView suggests that the top of the vertical batten (and indeed the "doorpost" at inboard side of bulkhead is distorted to starboard/outboard at top.I didn't see this on visual inspection - I used a phone camera so maybe lens distortion.I check carefully when I go to boat again.John V1447 Breakaway
Hi John, It is hard to see what is really going on in the pictures here, but a few thoughts. The head from the picture looks pretty good from what I can see. Check the head in two ways when you get back to the boat. Take a 5’-0” straight edge and place it under the head of the bulk head. See if you have a drop in it first. Then check for stress cracks on the cabin right by the ends of the head (wood support) at each end up where the fiberglass radius starts on the cabin . Check also on the bulk head where it is bolted through the hull flange into the bulk head. See if the bulk head is loose against the hull. What might be going on is the bulk head itself is moving inward at the floor at the doorposts. Which would keep pressure in the center of the head and not letting it drop. But it would bow the rest of the bulk head aft or forward. It is really hard to keep a radius tight (as in the bulk head sides against the fiberglass hull) if the live load is pushing down ward from the mast. I have been studying this for 6 months now on how to keep things from flexing or moving out of the radius points. Unless you support the bulk head 360 degrees. Something as simple as a spreader installed between the bottom of the doorposts. The stress cracks are mostly caused from the fiberglass flexing under loads. In this flexing the glass itself breaks, leaving the resin in tack for a short period of time. More flexing… the resin cracks. So if you find stress cracks by the bulk head , you have to much movement. So what can you do you ask? Well a lot in fact. Let me share what I am doing and maybe that will help. I am pulling all the factory bulk head systems totally out. I size a new head piece, new side panels and stronger door posts. All very easy to do, as you have the existing pieces to help for a pattern. In trying to find a good fix for this problem, I went to the higher end fiberglass sail boat sites. In there design they tightly fit their bulk heads to the hull and the cabin. Then bolt the bulk heads in with epoxy, but here is the key. They layup 3 layers of fiberglass mat all the way around the bulk head at the inside corners of all surfaces. What this just did, was take a bulk head 3/8” - 1/2” - 3/4” plywood and made the bulk head 6” to 8” at the load point or foot print where it sits on the hull on all surfaces. They also fiberglassed the bulk head panel complete as well. John, I am just finishing the cockpit bulk head using their system and it is believability strong. It is day and night from what it was like before I started. Remember our boats are only 27 feet long, things would be different if we had larger boats…much larger boats. I hope to be totally done with the cockpit bulk head this week end and I will send you the pictures. Knowing that the mast bulk head will be built the same way. Don’t worry John, it is all do able, there are so many guys who have reinforced their bulk heads in this group that the information is great. Ric has some great pictures of his redo, as others do as well. I am sure we can help you with this little problem. Larry Sent from Windows MailFrom: n4lbl alan.schulman@... [AlbinVega]Sent: Monday, August 25, 2014 9:40 AMTo: n4lbl alan.schulman@... [AlbinVega]
Hi Larry & all.See Album: Breakaway Bulkheads Album: Breakaway Bulkheads Breakaway Bulkheads Up DirectView SideView-2 SideView Generated by album
from MarginalHacks
on Mon Aug 25 17:31:57 2014 View on jkcray.maths.ul.ie Preview by Yahoo for 3 slightly blurry photos of starboard bulkhead.You\'ll need to download & rotate as appropriate.The vertical batten was fitted with the intention of stiffening he bulkhead but I think it is so light that it has very little effect.The photo DirectView suggests that the top of the vertical batten (and indeed the "doorpost" at inboard side of bulkhead is distorted to starboard/outboard at top.I didn\'t see this on visual inspection - I used a phone camera so maybe lens distortion.I check carefully when I go to boat again.John V1447 Breakaway
Hi Larry & all.See Album: Breakaway Bulkheads Album: Breakaway Bulkheads Breakaway Bulkheads Up DirectView SideView-2 SideView Generated by album
from MarginalHacks
on Mon Aug 25 17:31:57 2014 View on jkcray.maths.ul.ie Preview by Yahoo for 3 slightly blurry photos of starboard bulkhead.You\'ll need to download & rotate as appropriate.The vertical batten was fitted with the intention of stiffening he bulkhead but I think it is so light that it has very little effect.The photo DirectView suggests that the top of the vertical batten (and indeed the "doorpost" at inboard side of bulkhead is distorted to starboard/outboard at top.I didn\'t see this on visual inspection - I used a phone camera so maybe lens distortion.I check carefully when I go to boat again.John V1447 Breakaway
John,
This is the bulk heads at the cockpit /cabinet area. It is water tight and really …really strong. I will send you the mast bulkhead next.
Larry
Sent from Windows Mail
From: n4lbl alan.schulman@... [AlbinVega]
Sent: Monday, September 8, 2014 1:06 AM
To: n4lbl alan.schulman@... [AlbinVega]
Thanks Larry.
That\'s really helpful.
John V1447 Breakaway
This is the bulk heads at the cockpit /cabinet area. It is water tight and really …really strong. I will send you the mast bulkhead next.
Larry
Sent from Windows Mail
From: n4lbl alan.schulman@... [AlbinVega]
Sent: Monday, September 8, 2014 1:06 AM
To: n4lbl alan.schulman@... [AlbinVega]
Thanks Larry.
That\'s really helpful.
John V1447 Breakaway
Hi John, I posted some pictures for you, my boat is Lilly Two in the photo section of the club.LarrySent from Windows MailFrom: n4lbl alan.schulman@... [AlbinVega]Sent: ?Monday?, ?September? ?8?, ?2014 ?1?:?06? ?AMTo: n4lbl alan.schulman@... [AlbinVega]
Thanks Larry.
That's really helpful.
John V1447 Breakaway
On 06/09/14 03:24,
lewills30@... [AlbinVega] wrote:
Thanks Larry.
That's really helpful.
John V1447 Breakaway
On 06/09/14 03:24,
lewills30@... [AlbinVega] wrote: