Sagging Fiber glass hard top

[jerseyboy]

The back half of my fiberglass hard top has sagged quite a bit through the years (a picture of the 69 twin cabin shows the half top) The front half is fine since it's supported and attached to the windows.
There are two stanchions on a angle on each side of the hard top attached to the helm but someone years ago removed those 2 vertical stanchions
that were attached to the aft deck floor probably because they were in the way moving around the aft deck. I have raised the roof about an inch an a half
by using a bottle jack and adding spacer's where the stanchion attached to the roof but the real sag is in the middle. If I temporally disconnected the stanchions I thought a
couple of steel angle pieces 4 or 5 ft long screwed through the top of the hard top starting where they are secured to the front windows would be stiff enough to keep it straight. The screws would be the only thing showing from under the hard top. Better than ducking or hitting my head every time I enter or move around the aft deck. Any thoughts
or is this a reall bad idea?

 

[Captain Ralph]

Fiberglass angle or box tubing may be a better material.
Also, I think that is cored. And dry cored decks should not sag.

 

[jim rosenthal]

If you want to find premade fiberglass structural elements, try Strongwell- I think their factory may be in VA. They make all kinds of pre-extruded FRP designs and can probably supply what you need.

 

[SeaEric]

AFAIK the extended hardtop on these boats was added later. The short top was standard. There is evidence on my
41 TC that she was delivered with the shorter top. I'm only speculating - but I suspect (wild ass guess) my boat was returned to Hatteras
or an authorized dealer/service center for the extended top which is not only longer, but wider at the forward end. This
update included a wooden "arch" at the end of the side windows that is bolted through the roof and the side cabin structure.
At the aft end the 4 stainless steel pole supports terminate on to the aft taff railing structure. The roof is a heavy fiberglass
arched sandwich with some sort of core. It seems quite robust. I have seen other roof extensions that looked just like mine
and others that really didn't.
The key to the integrity of this roof is in the arched shape. If it's lost that then sagging would occur. I think I would try to fix it from
above rather than added support from below which would be in the way.

 

[madhatter1]

Eric, your boat looks great. Striving for the same look on our boats.

 

[jerseyboy]

Éric, I agree that fixing from above is the right option and only lifting the center to keep the curve angle. I have the half roof model and a canvas roof was attached to that to complete the enclosure. The sag is in the center at the rear of the hard top just aft of the helm seats. I was looking at the Strongwell company site Jim suggested and their night be something from them I can try. Thanks as always for help and advise from you guys..