Think of the trapezoid as a softer edge that goes all along the bottom of the bulkhead and already has a fillet attached (no putty fillet required) to make the tabbing follow an easy angle instead of a hard 90. It ends up working like a shock absorber and keeps the bulkhead from working like a really dull blade on a shear and cutting (breaking) the hull.

I am not sure but I think the bulkhead is also supposed to keep the stringers separated when the hull panels flex in the forward section. By being glassed to the stringers on the side I think the loads get spread across the stringer area too. With the bulkhead broken out I think you were getting really high loads on the forward edges of the stringers where they attach to the hull so any cracks there would get worse.

I went back and read the info again last night. It was definitely clearer. The first time I read it I think I blacked out for a minute. Thanks for all the feedback guys it really helps.

Normagain, The tank in mine was replaced some years ago by the previous owner. It was essentially a lesson on how not to install a fuel tank. It was truly a mess. Is there a difference in how the 20' and 23's casting deck was installed. Looks like your 20 has the foam and no bulk head. I think the bulkhead on my 23 is original?

The casting platforms in 20's & 23' look the same on top but how it is under them is different. The 20's don't have any bulkheads in them.

It's all making a little more sense. I guess when the bulkhead broke free, the main support became the two corners of the fish box? Hopefully I will be able to get the bulkhead back in next week. I am going to follow the suggestions and try to put a trapezoidal foam spacer in.

Yer gonna need this,
http://www.ehow.com/how_8181707_calc...oximation.html
:D

Ummmmmmm. Nevermind on the trapezoidal foam spacer.

What you need is fig newton approximation. :)

Just cut some foam. It has to be 2x the foam thickness plus the thickness of the bulkhead. Then cut (rip) 45 chamfers down each edge. You wind up with a flat on top that the bulkhead sits on nicely.

Now, that's just good comedy.

Yeah Dave, I agree!! I looked at it and closed the site, then went and made another drink and tried to remember how much I hated that formula stuff in school.!!!

Holy crap! I never would have guessed that removing the foam from the stringers would be such a PITA. At least we are one step closer to being able to put this thing back together.
http://img.photobucket.com/albums/v2...ps52cba30f.jpg

http://img.photobucket.com/albums/v2...psd39d311c.jpg