WXB-F19 Turtle Deck continues

[Spaceman]

I bet if you had the floor clecoed on when you pilot drilled the turtle deck skin to the upper longerons, then took the floor off to install the formers, then reinstalled the floor before you updrilled everything you'd be totally fine. I really don't think the turtle deck by itself would be rigid enough to tweak the whole fuselage unless you really tried to mess it up.

[wingnut]

Well just to put my mind at ease I cut a sheet of thin plywood the size of the front cross member to the 2nd one, about 23" X 40" and slipped it under the skin while the rest of it was still clecoed and drilled through the skin and plywood and added a shorter one about 8"X 18" and clecoed it to the back of #4 and down the longerons 8." The fuselage is as rigid as with the skin on now. I think I'll be able to access anyplace inside without removing them until the skin goes back on. It's apparently not necessary or everyone who didn't shore the belly up would have had a out of square fuselage at the end, but it didn't hurt to spend a couple of extra hours on it and I kinda like having a partial plywood floor. It's the custom look! Thanks

[sonex892.]

I bet if you had the floor clecoed on when you pilot drilled the turtle deck skin to the upper longerons, then took the floor off to install the formers, then reinstalled the floor before you updrilled everything you'd be totally fine. I really don't think the turtle deck by itself would be rigid enough to tweak the whole fuselage unless you really tried to mess it up.

I agree with spaceman. I think you might be overthinking it. The squareness of the fuselage is already set by the bulkheads. The only movement to worry about with the floor removed, is fore and aft movement of the sides. That is taken care of by the rear gusset shown below, the seat belt brackets and the front box section. With all those bits riveted in it'll be very sturdy without the floor.
Steve
Sonex 892

[mike.smith]

Funny story that has probably been told before. I visited the Sonex factory in 2006 when I was thinking about building my first Waiex. I asked John about that turtledeck fitting under the fuselage side skin. I thought if it was outside the water would not get in as much. His answer to me was "Water gets in everywhere, it also gets out everywhere". So... do it the way the plans say and don't think too much!

Yes. Think of how many pulled rivets are in the turtledeck, and how much water does or can come in there.

[wingnut]

I finally decided that although it's not necessary to obsess about the fuselage getting out of square without the belly skin on it, I went ahead and cut a 23X40 piece of 3/16 mahogany and slipped it under the front of the skin filling the front bay belly and drilled it through the skin and also put a 8X18 piece across the edge of #4 attached it across and 8" down the longerons, removed the skin and clecoed both pieces in place. It stiffened it up just as if the skin was still in place and I don't think it'll interfere with anything else I have to do with cables and whatever else I'll be doing. I think I like the custom look even if it wasn't necessary. Thanks for all the input.