sole/floors/hull attachment question

so my new laminated ipe floors are in and glassed, now to fit the cabin sole. seems i could "cast" a lip of bog between the floor ends and essentially have a flat shelf the entire perimeter to set the sole on. this would create a hard spot but spread over a relatively large area and at a particularly thick part of the hull. or hold the edge of the sole back from the hull and glass just the top surface to the hull (no way to reach the underside) this seems much less stiff overall. or is there a third method?
the sole is to be 3/4 marine doug fir, glass/epoxy encapsulated both sides, and the floors are 5 1/2" wide 24" on center. there are two sections of sole both 7' long and 5'wide. eventually both to receive solid teak and holly veneers. i assume ill bog down the sole to the floors... or would 5200 be a better choice for that attachment? id like to avoid mechanical fasteners in the bilge when i can.

basically looking for the best practices for sole installation.

thanks as always

 

You could cast a shelf (i don't know the deadrise angle whether steep or shallow) or just run short frames from floor to floor NEAR to the sides and let the sole cantilever the last little distance.
Say your floors are spaced at 18", you might use 3/4 x 1 1/2" hardwood set on the flat and let in to the tops of the floors to span between floors. They could be set just far enough out to touch the hull and you could put a glob of epoxy there where they touch to increase surface area and solidify everything.
Lazy mans way of doing it I guess.

 

When I did my cabin sole I pretty much replicated what the original builder did. The original cabin sole held up well for 30 years.

I used exterior graded ply (coated a minimum of 3x with generous layers of epoxy) and pressure treated 2x4 framing lumber. I made up what PAR called "sole stringers" and installed these over the floors. The sole stringers were spaced so that the plywood had a solid place to land and were 16" on center. Towards the inside edge of the topsides (where you're thinking of casting a shelf) I fit the sole stringers within a few inches of the topsides. You could steam bend them if you wanted to be fancy but I just cut them close to the hull where the topsides began curving towards the bow. I cut the sole about an inch short of where it would join the topside and used fairly heavy 8" wide fiberglass tape to tab the sole in.

Once the settee and cabinets are installed and tied into the boat you'd be surprised at how solid this construction method is. I understand your reluctance to use fasteners, however I can say that after 30 years the silicone bronze screws used by the original builder were fine. There was no evidence of fastener failure and the screws were all that was holding the structure together. I used silicon bronze screws and Sika 291 to bond the plywood sole to the "sole stringers".

 

thanks alan...i guess the basic consideration is creating the hard spot along the perimeter. youve got the floors in contact with the hull through the turn of the bilge and then additional glass spreading their loads, i see the margin of the sole contributing so much to overall stiffness that is should be firmly attached to the hull, no?

 

You could bed the fore/aft margin frames fully or partially. They wouldn't create stress risers in any measurable way. You could do this a lot of different ways. I was just suggesting a way that saved epoxy. A touch or two of a disc sander on the hull-facing corner of the margin frames and a small amount of epoxy will work as well as anything else.