A question about how to attach the fiberglass top to the windshield.

[wimberosa]

TLDR: Mushroom on top pulls down against fiber glass. Compressed "bell" end of pin goes into metal drip rail.

Its a bit easier to understand the correct rivet orientation when you consider compressive versus torsional strength
of fiber glass. The rivets have a mushroom head and when you compress them in a rivet tool, the pin portion will "bell"
out requiring good side to side torsional strength at the "bell". So the "bell" portion needs to be in the metal drip rail which
has good torsional (side to side) strength....whereas the mushroom top pulls down on the fiber glass and requires good compressive strength.

As a bad experiment... If you happened to do it the opposite way, then you'd immediately see that when the pin "bells" out against the fiber glass, you get much less strength because fiber glass wallows out at the hole much easier than metal.

 

[Its me shaneus]

My fiberglass cap was in tough shape, i had to redo much of it with fresh fiberglass cloth, inside and out. The original rivets were removed and the hole locations lost.

When redoing these I got the top all back on and drilled through the inner steel holes up through the cap.

I used stainless 10/32 button head allen screws with nylocks on the inside. This let me control the tension, I was a little concerned that a rivet gun might have enough clamping force to cause deformation of my freshly redone cap.

 

[coinoperated40]

In one opinion, you would think that the rivet expands as it is compressed and you would not want it to expand on the fiberglass but on the metal. As the metal can handle the load. True that some expansion on the shaft is expected. This would put the cap of the rivet on the fiberglass side.

 

[Augustiron]

Timely thread, I just decided to take mine apart yesterday

 

[Augustiron]

Just to add a little helpful info:

Every one of my bolts that went from the sides to the top broke off disassembling the top. I usually have great success welding a washer and a nut to the remnants of the broken bolt to extract but that didn't work on any of these.
I was stuck with a ton of broken bolts and no way to get them out as they kept breaking deeper and deeper from the surface.

Before I decided to take the metal section off, I realized I was going to have to replace all the inserts and found these nifty weld-in inserts and was able to drill out the existing inserts really easily.
I originally planned on just welding them in with the metal rail in place, but after working on it more and seeing how poorly it was still attached to the fiberglass, how many rivets were missing, some rain gutter rust and dents, I just decided to remove it which will make welding these in even easier.
But they can be easily welded in place to replace broken bolts/inserts with the metal rail still in place.
They are nearly identical to what is on there from the factory

 

[charliemeyer007]

Hi Augustiron Your screenshot_20251203-080725.webp doesn't show up (wrong format?) What weld in insert did you use?
The fiberglass on my top has had a rough life - perhaps next year I'll get after it.

added Not sure what happened but its there now -

Thanks

 

[coinoperated40]

Timely thread, I just decided to take mine apart yesterday

View attachment 4041603

I also have two under construction. The metal rails are both in non repairable condition. Purchased the replacement from CCOT. I will hopefully start on the weld and replacement after the holidays.
Good luck on your project.

Upside down on the ceiling for now.