Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 02-12-2014, 10:22   #16
Registered User

Join Date: Dec 2012
Location: Chicago, IL
Boat: 40', Farr 38
Posts: 63
Re: Rotten Bulkhead Repair

Attached is another pic looking aft towards main bulkhead.
Attached Thumbnails
Click image for larger version

Name:	Forward Bulkhead.jpg
Views:	149
Size:	418.4 KB
ID:	92747  
__________________

__________________
Capt Ben is offline   Reply With Quote
Old 02-12-2014, 11:26   #17
Registered User

Join Date: Apr 2011
Posts: 2,243
Re: Rotten Bulkhead Repair

I had to repair a smaller area on my Bristol, under the galley sink where it had been getting damp long term. First step was to build up fibreglass inside the cupboard, with two functions : restore the strength, and seal out any water, allowing the wood to dry out.

The damp had discoloured the holly in the floor. Removed the affected bits, and applied Smiths CPES.



Removed all the rot at the bottom of the teak ply, and applied Smiths CPES again :



Built up the bulkhead with fibreglass tape and epoxy :



Faired with epoxy mixed with fairing additive : (not the final result, took at least 3 cycles of fill and sand to get it really smooth)



Covered with self-adhesive teak veneer :



Veneer has had 5 coats of spar varnish. Replaced the missing holly strips, bonded in with epoxy. The final colour match of the holly is much better than in this pic, took some experimenting with wood stains!



The repaired panel is the one to the left of the engine compartment door. Couldn't be happier with the result, and the teak veneer worked out beautifully.
__________________

__________________
Bristol 31.1, SF Bay.
MarkSF is offline   Reply With Quote
Old 02-12-2014, 11:34   #18
Marine Service Provider

Join Date: Oct 2011
Posts: 1,205
Re: Rotten Bulkhead Repair

Capt.,

I seriously doubt that the area under the door adds ant structural stiffness.

The bulkhead in question is acting as a large diaphragm, which resists compression of the hull sides by transferring the load to the large glassed in floor timber.

The fact that the door way runs from floor to overhead suggests that you have 2 independent diaphragms, port and starboard. As the lever created by the narrow sections under and over the door would impart nothing to the remaining bulkheads as far as strength.

The strength in both of these 2 separate diaphragms, comes form being tabbed at the floor timber, the hull side, and fianlly the overhead.

Your biggest worry then becomes, how much rot is in the bottom of the bulkhead running athwartship from the bottom of the door, port and starboard. This where you need to focus your investigation on for strength.

The under door is cosmetic, except the floorboard stringer, and the door molding. It has to be just strong enough to support those loads.

Lloyd

Lloyd



Quote:
Originally Posted by Capt Ben View Post
Still seeking a response to my fundamental question:
1. Has the bulkhead integrity and hull stiffness been compromised (if no repair is made)?

Obviously, I'm planning on repairing this. I've already removed all the rotten wood, etc. I just want to understand what, if any structural implications there are to this repair.


Sent from my iPad using Cruisers Sailing Forum
__________________
FlyingCloud1937 is offline   Reply With Quote
Old 02-12-2014, 13:17   #19
Registered User

Join Date: Dec 2012
Location: Chicago, IL
Boat: 40', Farr 38
Posts: 63
Re: Rotten Bulkhead Repair

Loyd,
Thank you for your observations. What you have stated is essentially what my gut has been saying.

I've dug out and removed all soft and rotten wood athwarthships. The pictures show how far to port and starboard I had to go.
__________________
Capt Ben is offline   Reply With Quote
Old 02-12-2014, 13:19   #20
Registered User

Join Date: Dec 2012
Location: Chicago, IL
Boat: 40', Farr 38
Posts: 63
Re: Rotten Bulkhead Repair

Quote:
Originally Posted by MarkSF View Post
I had to repair a smaller area on my Bristol, under the galley sink where it had been getting damp long term. First step was to build up fibreglass inside the cupboard, with two functions : restore the strength, and seal out any water, allowing the wood to dry out.

The damp had discoloured the holly in the floor. Removed the affected bits, and applied Smiths CPES.



Removed all the rot at the bottom of the teak ply, and applied Smiths CPES again :



Built up the bulkhead with fibreglass tape and epoxy :



Faired with epoxy mixed with fairing additive : (not the final result, took at least 3 cycles of fill and sand to get it really smooth)



Covered with self-adhesive teak veneer :



Veneer has had 5 coats of spar varnish. Replaced the missing holly strips, bonded in with epoxy. The final colour match of the holly is much better than in this pic, took some experimenting with wood stains!



The repaired panel is the one to the left of the engine compartment door. Couldn't be happier with the result, and the teak veneer worked out beautifully.
Mark,
Great job with your re-construction. I sure hope that I can match the teak veneer and stain as well as you have. Looks like a challenge....
__________________
Capt Ben is offline   Reply With Quote
Old 02-12-2014, 15:45   #21
Registered User

Join Date: Nov 2013
Location: Slidell, La.
Boat: Morgan Classic 33
Posts: 1,102
Re: Rotten Bulkhead Repair

I would have to say that yes, the structural integrity has been compromised. That bulkhead is in a key area of the hull where mast and keel loads are all concentrated. The real question is how much is it compromised, and, as you're asking, what's the best way to fix it.

Short of pulling all that woodwork, grinding out the fillets and glass holding the bulkhead in, scarfing in new material to replace the rotten portion, and filleting and tabbing the new lower portion (which many would say is the correct way), I like the idea of using two pieces of 1/4" coosa board and building the area up with roving. From the pictures it looks like your boat has a substantial laminate schedule, if the bonds between the new material and the existing glass and wood are good, the repair should be almost as strong as the original configuration.

Whichever resin you use, for thickening use silica (to avoid runnyness) and milled fibers (for strength).

If you can't find a small piece of 1/4" coosa board let me know the size pieces you need, I can mail them to you (but you have to reimburse me for the postage). I have this piece left over from building a dinghy for my boat. The second picture is to give an idea of the flexibility.
Attached Thumbnails
Click image for larger version

Name:	c1.jpg
Views:	88
Size:	169.7 KB
ID:	92779   Click image for larger version

Name:	c2.jpg
Views:	84
Size:	231.0 KB
ID:	92780  

__________________
jimbunyard is offline   Reply With Quote
Old 02-12-2014, 20:52   #22
Resin Head
 
minaret's Avatar

Cruisers Forum Supporter

Join Date: Aug 2007
Location: Seattle WA
Boat: Nauticat
Posts: 7,199
Images: 52
Re: Rotten Bulkhead Repair

Quote:
Originally Posted by jimbunyard View Post

Short of pulling all that woodwork, grinding out the fillets and glass holding the bulkhead in, scarfing in new material to replace the rotten portion, and filleting and tabbing the new lower portion (which many would say is the correct way)



Count me one of the many!
__________________
O you who turn the wheel and look to windward,

Consider Phlebas, who was once handsome and tall as you.
minaret is online now   Reply With Quote
Old 03-12-2014, 00:33   #23
Registered User
 
Terra Nova's Avatar

Join Date: Apr 2007
Location: Marina del Rey, California
Boat: Freya 39 cutter- Terra Nova
Posts: 3,645
Re: Rotten Bulkhead Repair

After cutting the rotted area back to 100% dry, sound wood, I would make repairs using lapped joints with wood encapsulated and glued with WEST epoxy; then tabbed in using bi-axial and epoxy. Additional reinforcement and lapping can possibly be done by creating a form of "baseboard" that covers the repaired area, well overlapped onto fresh wood.
__________________

__________________
1st rule of yachting: When a collision is unavoidable, aim for something cheap.
"whatever spare parts you bring, you'll never need"--goboatingnow
"Id rather drown than have computers take over my life."--d design
Terra Nova is offline   Reply With Quote
Reply

Tags
head, rot

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Replacing a Rotten Bulkhead - Project Report Beersmith Construction, Maintenance & Refit 12 18-09-2012 13:34
Rotten Bulkhead! Opinions of Those Who Have Strayed Down this Dark Path Sailmonkey Construction, Maintenance & Refit 14 06-03-2010 10:45
Replacing Rotten Wood in Cabin Top rebel heart Construction, Maintenance & Refit 21 29-06-2009 13:39
Rotten drain lines .... could have been a disaster! mobetah Construction, Maintenance & Refit 1 10-01-2008 20:58



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 14:08.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.