Windshield fitment

[Joe]

I had to raise the left side of spider to fit windshield and make car even. Once WS is set and i remove prop do i have to worry about it cracking from the pressure or it be good?

 

[Ryan L]

If you remove the prop, does the fiberglass sag back down?

If the answer is yes, and the windscreen is bonded in place, this will then place a stress on the windscreen, and will be pulling the screen corner downwards which will apply extra stress to the screen. If the screen is loaded, then it may only take the lightest of hits from a rock being thrown from a car in front to cause the screen to crack. The other problem is that the whole lot may sag over time changing the panel gaps and door clearances.

I would be trying to adjust it, so that it does not need the prop to maintain its shape. Either through applying heat, to get the resin up towards its glass transition temperature "Tg" where it becomes a soft plastic that can be bent (will depend on the type of resin used)
or
by cutting a slit into the A pillar on the tension side, the slit will then open up allowing the pillar to conform to the new position. With the roof and pillar propped in the new position, a scarf joint repair can be made to allow the slit to be closed. This should then hold the roof line in the required position.

That would be my thinking, and how I would approach it.

Will follow to see what others have to say.
Ryan

 

[JP Verweij]

I used infrared heaters to heat up the spider and rechape it using some timber between floor & roof to raise the spider so the screen sits flush.
Heat it up, bring it into shape and cool down quickly with towels soaked in water.
It might need a few attemps.

Got this tip from David Hart Racing crew after Oliver Hart ended up on its roof with their Gelscoe forty and the Gelscoe replacements pannels didn't fit.

 

[Ryan L]

What is the glass transition temperature of TotalBoat Polyester Resin? – TotalBoat

The glass transition temperature (Tg) is when a material changes state from a rigid, solid form to a soft, pliable form. The Tg of TotalBoat Polyester Resin is 188.834°F (87.13°C).

TotalBoat Polyester Laminating Resin - Marine Fiberglass Resin


What is the glass transition temperature of vinyl ester resin? | ResearchGate

 

[Randy V]

Wow - I heated my spider up to 200F to get it to go back to where I needed it to. I let it cool slowly though rather than chill it. From that point forward, I had a prop holding up the center of the spider until I welded mounts to the top of the roll cage that the spider was then fastened to..

 

[Ryan L]

did the heating work Randy @Big-Foot

 

[Joe]

Wow - I heated my spider up to 200F to get it to go back to where I needed it to. I let it cool slowly though rather than chill it. From that point forward, I had a prop holding up the center of the spider until I welded mounts to the top of the roll cage that the spider was then fastened to..

I’m trying the heat.I don’t have full roll cage to attach front to, I’m going to try another direction with it. Instead of of Propping left top up I’m going to try to pull bottom right down if that makes sense lol

 

[Ryan L]

Joe, had another thought. Normally the roof skin is a two-part piece. i.e. an inner and outer. So you will be fighting the alignment of the inner and outer skins relative to each other. You may be able to get a multitool down between the glue line and separate the two skins. then you are only trying to bend one skin, and not trying to get the glue line to shear across itself. I think you will find that if you separate the two skins it will flex a lot easier, and you can probably glue the two skins back together at a later stage using some "Plexsuss" to help maintain the desired shape.

If the two skins have been glued together out of alignment from the start, or they were pulled out of the mold before the glue had fully set, and its twisted, then this could be the source of the error.

Plexus Structural Adhesives | Industrial Metal & Methacrylate Adhesive (itwperformancepolymers.com)

 

[Randy V]

did the heating work Randy @Big-Foot

Yes…. It took more than an hour of waving the heat gun back and forth, top and bottom, but I was able to get the “Z” and sag out of the spider..

 

[David45]

I've used a range of sealants in my time, ps 870 b1 2 has particularly stood out as a reliable sealant.

 

[joe]

What's the most best way to heat up the fiberglass to get it to take a new shape?

 

[Morten]

What's the most best way to heat up the fiberglass to get it to take a new shape?

Leave it outside in the baking sun and put weights on places to lower the fiberglas, let it cool down, and repeat if needed.

I’ve reset my doortops with sunshine and a carbattery as weight to get the top of the doors lowered into correct shape.

 

[joe]

Do these fiberglass bodies move around after everything is complete and the car gets parked outside while driving?

 

[Randy V]

Do these fiberglass bodies move around after everything is complete and the car gets parked outside while driving?

They sure can… Particularly if hot and unsupported…. That’s why it’s important to have your spider well supported and the windshield bonded in place..
I always open the engine bay up when I stop for the day to let out latent heat, then button everything up before bedtime.

 

[JP Verweij]

I used infrared heaters hanging on the ceiling placed above the spider.aboit 3ft above.
Didn't take long before inside & out was soft enough to reshape and cool it down with wet towels.
I used some timber to raise the spider till shape was perfect for the doors to align (top of the doors) and the screen to fit.

I did this with the doors fitted.