Bulkhead Connection - Cored Construction

Man you've got some work ahead of you! I thought I was crazy. Now in regards to your wanting to set the bulkheads on 1" spacers and glue them in with thickened epoxy, whay not just give yourself a smaller, maybe 1/4" or even 1/2" space? For one, you'll use less epoxy to glue them in, and two, it's a PITA to get a good radius because you'll be constantly pushing your thick epoxy through the gap instead of having the smaller space in effect stopping the epoxy. I'd just use some 1" square by 1/4" thick hardwood spacers and tack them to the hull with hotglue or epoxy along the draft lines you draw in the hull for the bulkhead placement. Worse case scenario, you can always just glue a higher piece on top to get more height.

 

Integral single flange bulkheads.

The white ones is andrews 28 mast bulkhead, on male mold. http://www.sylvanayachts.com/

The black one is nautor swan 601 with female molding. It was in the text that swan bulkheads were bonded with spabond epoxy. The bulkhead is a forefront partial bulkhead. The two horns ?? in the bulkhead is probably for joining continuation of framing. The indentation in the flange is to match plating thickness, hull centerline is not cored,

 

Mongo,

It's all about the journey! However, it does give one pause when the slightly demented boatniks on this forum think you're over the top.

You are correct about the 1" spacer, I sorta had that distance in my mind relative to a foam spacer, but I agree a smaller gap is appropriate.

fcfc,

Thanks for the tip about the Scott Bader product, Crestomer. I really like the looks of this stuff. I've also had a lot of good feedback from the U.S. technical rep. I'd be happy to post a synopsis of our communication but am uncertain about the rules regarding such commercially related information. If someone could fill me in on the rules, I'll edit the e-mails accordingly.

Sea Jay

 

Regarding the foam spacers to distribute load and eliminate hard spots.....
I've attached a couple of pictures of what I did on my 1973 Silverton. The engine stringers and the floor (I think of the 'floor" as a transverse 1/2 bulkhead) forward of the engine are shown.

The stringers were formed on plain old polystyrene foam insulation such as you would find at Home Depot. I laminated 4 layers of 1708 mat over the entire stringer, and 2 additional layers in the areas near where the engine mounts will be bolted (the photo was taken after the first lamination was done and you can see the wooden blocks where the engine bearers will clamp).

Anyway, rather than deal with trapazoids on a one off project like this, I decided to cut triangular pieces of the foam from the scrap I had left over from making the stringers and floors (bulkheads). I used a carpenters angle gauge to get the proper angle and carefully....slowly ran the foam through my circular saw. The foam can get away from you when cutting if you try to go too fast, I found.

Once the foam was cut and dry fit properly I mixed up some quick set epoxy and tacked the triangle stock in. Worked out great, and since the stringers were made of foam as well, I didn't feel there would be any issues with "hard spots". The roughly 45 degree angle transition from the vertical stringer to the hull bottom made the application of the fiberglass much easier.

Hope this helps,

MIA

 

MIA- gotta question for you off topic (sorry) I see you got a V-drive, how is that mounted- are the engine tranny soft mounted, and the v-drive hard mounted with a double u-joint in between to take any engine vibrations out of the v-drive? you could reply to me at daniyel.jones@usmc.mil THANKS!

 

MIA,

Thanks for the suggestion.