Main Bulkhead Expertise

[jbibb]

Following up on a failed main bulkhead at the port chainplate, I decided to contact a local shipwright to give me an estimate...this job is not something I want to "learn" on and with sailing season here, I wanted to get the job finished sooner rather than later.

I assumed a complete bulkhead rebuild as insurance for such a critical structural piece. The shipwright suggested that he could splice a new piece of marine plywood in without ripping my cabin to pieces...

Question...at what point do you not question his suggestion and/or question whether or not to play more conservative? Any experience with splicing rather than a complete replacement?

[camaraderie]

This is done quite often. The main thing is to get the assurance of the shipwright that the repair will be as strong as the original.

[jbibb]

Thanks. "Done quite often" is what I wanted to hear.

[knuterikt]

Hi
I think that splicing in a new piece sounds like a good solution, but it would help if you can give more information about the damage. Like size, placement and accessibility to the area.

I’m assuming that your chainplates are bolted to the bulkhead.

There are different ways to do this depending on the size/shape/placement of the damage. One way to solve this could be to do what we call sistering. To do this you cut out the damaged part replacing it with new piece with same shape. On one side opposite to the chainplate you put a larger piece covering all the joints between old and new bulkhead, use marine epoxy glue to bond it all together.

Ask the shipwright how he will solve your case.

It’s important to get all the damaged wood out.

After repair it also important to get the cause of the leak fixed, you should also check for leaks on the other chainplates.

[soulesailor]

Cam, could you elaborate how a carpenter would splice in a new piece of bulkhead? I can see sistering on a new piece, like a scab, as knuterikt posted, but scarfing a plywood bulkhead in place seems flimsy if not impossible. Thanks.

[jbibb]

Thanks knuterikt. The damage is mostly at the port bulkhead that the chainplate attaches to with (5) 3/8" thru-bolts with steel straps on both sides of the plywood bulkhead. This supports the upper shrouds. There is a bit of rot on the starboard side, however the port is really bad all the way down the hull almost to the base...probably including the base. I'm sure there will be a different proposal if upon rot removal, the base is compromised. My thought is the tabs that connect the bulkhead to the steel compression beam located beneath the bulkhead.

Yes...leak repair!

[camaraderie]

Soul & Jbibb...Yes...I would imagine the new wood will be cut to fit and re-tabbed at the base and the whole piece glassed in place with woven roving. i would imagine a slightly thinner piece of ply will be used to allow room for the roving and to allow everything to be sanded down to the same overall thickness as the rest of the bulkhead. Once the rigidity/strength is established, then new veneer may be applied to give a finished appearance and the chain-plate holes re-drilled for final attachment to the newly bedded and leak free plates!
Knut has it right for when appearance on one side is not an issue...but in this case, I think both sides will need to look good.

[Sailormann]

The damage is mostly at the port bulkhead that the chainplate attaches to with (5) 3/8" thru-bolts with steel straps on both sides of the plywood bulkhead. This supports the upper shrouds. There is a bit of rot on the starboard side, however the port is really bad all the way down the hull almost to the base...

If you can, I'd suggest you ask to have the whole bulkhead replaced. The problem with the starboard side is not going to get better with use. You may well find that patching up one side and then the other is both more expensive and less pleasing in appearance in the long run. Good Luck !

[soulesailor]

Cam, thanks for the explanation. That's quite a procedure; lots of different skills involved.

[jbibb]

I'll take this up with the shipwright great advice....is this a job for experience shipwright or is this something, limited fiberglass with patience and a good website can produce?

The is a website, Wilkie's Sailboat Page has the proceedure, same boat etc.