Forward removable bulkhead

[Clyde]

Does anyone have any thoughts on keeping the bulkhead off? I removed it to clean the forepeak and install a backing plate for a bow cleat. At first glance it seems to be an ideal "shelf" for storage of sailbags, cushions, etc. which is not possible with the two small openings when the bulkhead is in place. Since it is made of relatively thin plastic it does not seem to have any structual effect.

The only advantage I can immediately see to leaving it on would be additional flotation in the event of a capsize although it would probably fill eventually.

I'd appreciate any thoughts.

[Bob Damon]

Our class rules require it to be in place as it provides a structural support to the foredeck. It can be removed if an alternative structural support is in place. Some folks place an aluminum post between the keelson and the top of the cuddy.

[GreenLake]

Even if it is "thin" plastic, the strength it adds is significant. Unlike the simple post, it does more than help the foredeck stay up - I would expect it to also provide significant additional resistance to twisting the hull.

If you were to replace it by a post, I would look for ways you could add stiffness elsewhere. On the DS1, the obvious place is the cuddy opening. While the top edge is reinforced (with rebar, if all things, at least in the early DSIs) the sides of the hull and the hull/deck connections are not.

Glassing on a "rib" created over several inches of foam core might add some stiffness in that area and resist overall twisting of the hull.

[algonquin]

I agree that even though the material is thin, it provides not only vertical weight distribution of the deck but also lateral stiffening and distribution of forces from the hull while sailing. If that is the case then the bulkhead would be structural by design. My DS is circa 1961 and has the bulkhead assembly as well as a compression post from the keelson to the deck just forward of where the cuddy begins. The post appears to be factory installed.

I like GreenLake’s idea of providing additional stiffening to pressure points within the hull. under the foredeck, and the cuddy roof. That combined with a compression post should allow you to leave the bulkhead off so you have easier access to the storage area. Brad

[Clyde]

Thanks, folks, for the suggestions. My cuddy top is OK as it's supported. I'll try to figure out something to keep the strength but open it up for better storage.

[dannyb9]

how did you remove the bulkhead? seems to me that you could cut a larger, elliptical or rounded hole in the bulkhead that would keep much of the strength of the bulkhead- turning it into a "web"- while gaining access to the space. the remaining "ring frame" could even be reinforced with a plywood "face" that could be attractive if made of a nice piece of varnished marine ply.

[Clyde]

The bulkhead simply unscrewed. Making a larger hole is a good idea although I like the idea too of a nice wooden frame. I'm going to make floorboards so I can do a ring/frame at the same time.

Thanks!

[lbdavis]

I agree that even though the material is thin, it provides not only vertical weight distribution of the deck but also lateral stiffening and distribution of forces from the hull while sailing. If that is the case then the bulkhead would be structural by design. My DS is circa 1961 and has the bulkhead assembly as well as a compression post from the keelson to the deck just forward of where the cuddy begins. The post appears to be factory installed.

I like GreenLake’s idea of providing additional stiffening to pressure points within the hull. under the foredeck, and the cuddy roof. That combined with a compression post should allow you to leave the bulkhead off so you have easier access to the storage area. Brad

Sorry to dig up a year old post, but can you, GreenLake, or someone else explain this more or point me to this? Thanks!

[lbdavis]

I think I found it.

http://forum.daysailer.org/forum/viewtopic.php?t=4002

?

[GreenLake]

That's a good recent one.

Remember, it matters whether you want to be able to use your DS in racing under class rules. Quire a few people on this site don't care about this, either for lack of interest or lack of opportunity.

If you are in an area where fleets exist, changes to your boat that "void the warranty" that is, make it ineligible to race under class rules will affect the range of buyers available should you ever decide to sell.

Actual removal of the bulkhead would be one such change, however, adding stiffeners is not (I guess as long as you don't use carbon ). If you're interested in keeping options open, make it possible to re-mount the bulkhead for a later buyer.

[lbdavis]

Thanks.

I'm not racing. I actually own an Explorer (sailstar) and I want to stiffen the whole boat, particularly the 'cabin' top, fore deck, and gunwales.

Besides just wanting a stiffer boat and deck, I do plan on painting her eventually and want to reduce movement/crazing.

I've been considering either adding bulkheads with large openings near the rear of the cuddy and near the rear of the foredeck or adding pillars that displace weight onto stringers. Either way I would add more athwartship stiffening under the deck (would that be called 'stringers' under a deck, too?).

I'd like to keep the overhead glass work to a minimum, so that knocks out glassing in another layer....

I came here hoping to here others' solutions or learn of what 'solutions' to avoid.

Thanks again for any more tips or any other threads you could point me to.

[GreenLake]

For overhead work you'll want to use a backing medium.

I would use a nice plastic foil, something heavy, think freezer bag, not kitchen wrap, and lay up the laminate on it, then transfer the whole thing to its overhead location and work it into place. The plastic backing can remain in place until the laminate has cured. If you've squeezed excess resin out of the laminate, there should be very little mess with that method.

Also, if necessary to counteract sag, the plastic gives a great surface against which to pus supports, ending in foam rubber, to help the laminate conform.

I wouldn't necessarily attempt a full liner with that, but a stringer, by any name, should work fine.

There's a video out there where someone takes this one step further and places dry fiberglass into a large flat plastic bag. Then pours in resin, and works the resin into the laminate through the bag, the bag catching all the excess resin he's squeezed out. He then trims the bag and laminate into a neat rectangle sandwich, which has plastic on both sides. The top sheet is pulled off just before application, further reducing mess. Having a top sheet arguably allows more excess resin to be squeezed out, making for lighter and possibly stronger laminate.

[JACK FLASH]

Actual removal of the bulkhead would be one such change, however, adding stiffeners is not (I guess as long as you don't use carbon ).

Where in the rules does it say you cannot use carbon for additional structural support.

[GreenLake]

The rules say:

The hull and deck shall be made of fiberglass and resin

The hull and/or deck may be reinforced or stiffened on the inside.

This leaves open the question of whether the stiffeners are part of the deck and hull or not. Given that the original DS used all sorts of stiffening materials from wood to rebar , the conclusion would be that effectively, the stiffeners are not covered by the restriction quoted at the top. So, it does look like I was wrong and you are free to indulge in carbon stiffeners.

I also found that the rules allow for replacing the bulkhead by "equivalent deck-supporting device", without further specification, which would seem to leave it to the class measurer to rule on what is equivalent.

[JACK FLASH]

That was my take on it. I was planning on replacing the aftermarket 2x6 mounted between the cabin top sides with a carbon peice to reduce weight.