Bulkheads needing replacement..why?

[scgilligan]

If someone tells you their boat's bulkheads need to be replaced should the first question be "What is leaking?"?? Are there any other reasons a bulkhead would need to be replaced other than water damage from leaky cabin? Is this a costly fix? Easily performed without professional help? Expensive? Special Tools, etc.?

[TintedChrome]

It's one of those things that in theory is easy - take out bulkhead; create template; cut out new bulkhead; tab in place.

In practice however, accessibility to the tabbing, and cabinetry constraints make this job a real PITA in some boats. Especially when inner liners are involved.

A lot of boats had their bulkheads installed prior to the deck being attached to the hull which requires some creative thinking for removal/installation later on. As an example, I have to do mine this spring and my port bulkhead will need to go in in two pieces (one piece won't fit through the companionway). Many times the bulkheads won't come out in one piece either, requiring you to to create a template out of cardboard and keep trial fitting that until it's right, then transferring to ply.

If you're handy - basic fiber-glassing and wood-working skills are required - and take your time there's no reason you can't do this yourself. If you're not, having someone do it usually is not cheap.

And from what I've observed, 99% of the time bulkhead replacements are necessitated due to rot from leaks and/or standing water.

[sailingdog]

Generally leaks are the biggest source of a bulkhead needing replacement. Water intrusion generally leads to the bulkhead rotting and weakening.

Replacement depends a lot on how the boat was built. Stick built boats that use stringers and floors to provide internal hull rigidity and have the bulkheads tabbed in can often be easier to work on than boats with pan liners that may be blocking access to the bulkhead and make replacement more difficult.

Don't forget that the bulkhead shouldn't generally go to the hull, or it can cause a hard spot that will cause the laminate to hinge and eventually fatigue and fail. It should be separated from the hull by about 3/8" of ductile closed-cell foam and the tabbing should be faired to support the bulkhead without sharp bends in the glass for maximum strength.

[scgilligan]

Another "newbie" question. I assume the bulkhead provides rigidity to the hull and keeps it from bending/twisting/collapsing..is that correct?

[sailingdog]

Originally Posted by scgilligan

Another "newbie" question. I assume the bulkhead provides rigidity to the hull and keeps it from bending/twisting/collapsing..is that correct?

Usually, but not always... some bulkheads are not structural, and as non-structural elements, don't help prevent the hull from bending, twisting or collapsing to any real degree. That is one reason why modifying, moving or removing bulkheads should be done on a boat with extreme caution.

In fact, on many smaller boats, the forward bulkhead in the cabin not only provides the hull with some rigidity and helps resist torsional loads, but it also acts as a support for the mast and transmits the loading of the rigging from the mast down to the keel or hull. Also, on many boats, the forward bulkhead is used as an anchor point for the shroud chainplates that support the mast.