My crazy project

[RJS]

I started this top from scratch over a year ago. Many thanks to Tim for all the help, ideas and free stuff, and to Zeke for convincing me I could actually do this (I will get even later).

It is not done yet, but the end is in sight. If I would have known it would be this much work, I don't think I would have started in the first place.

I had always looked at the tops out there and thought I could do better (famous last words). All of the others out there have too many flat areas with no curves for my taste, so this one is all curves and no flat areas.

Sorry for the lighting in the pictures (white on a bright day). I will take more later if there is any interest.












Rob

[zekow1]

Rob.Rob, Rob
I am sure your wife and kids are glad you are out in the garage instead of sitting on your lazy-boy watching football or re-runs of I love lucy.
The reason the pictures are so light is :
IT LOOKS GRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRREAT!!!!!!!!!!
To Ceasar what belongs to Ceasar.
Hey Get even now.
Congrats Mate[:D]

[silverseven]

arrrrgh, why did you have to be all the way over in Arizona!!!!


Was just talking roofs today with another member, btw yours looks fantastic!!

Fibreglass I'm guessing????


Planing on doing a run , once complete???

Ron.

[RJS]

Yes it is fiberglass, and I had to make a mold first (actually the mold was 2nd - the "plug"/template was the first and hardest step).

When I started the project I had dreams of making a bunch and selling them. I am not saying I won't sell some down the road, but it has been a lot more work than I thought it would be.

Maybe I will get faster and it will get easier down the road. At this point I am not willing to spend thousands of dollars on equipment that would make this a faster process.

If I ever sell them I will list them in the for sale forum here first.

Rob

[Cobber]

<font size="2"><font face="Comic Sans MS">Now that you have the mould you could farm the work out to someone who has all the equipment to do the job quickly and economically (remember time = money) </font id="Comic Sans MS"></font id="size2">

80'Triumph TR7, , 73'Land Rover (Ford 351. V8),
'89 Ford Fairlane
85'Alfa 90, 69'Ford F250.
76' Ford F100

[Marko]

how much layers?

matt or roving? poliester or epoxy?
what kind of gelcoat on the outside?


couple of suggestions:

bottom layer(facing the passangers) should be aramid (kevlar) roving bidirectional 2x2 or something simmilar.
why?

its cheap
it will make the top resistant to cracking.
it will make the topp a bit flexible to better resist impact
to help align the top to the poorly assembled tr7 bodywork ( it wont be so rigid)
in case of a crash passangers wont have the face full of glass fibres.

try to copy the locking mechanism of the fabric roof , and laminate a metal( aluminum) beam that will seal the gap between the windshield and the hardtop. so that the hardtop doesnt get blown open on high speeds and it doesnt leak.

metal frame for the rear glass (laminated in the hardtop) so you can use stock glass and rubber from tr7 coupe or any other mass produced car. custom made glass is expensive.

there are lots of hinges, and locking mechanism's from the racing part supplyers so it shouldn't be a problem to find a suitable to lock down the hardtop.


next for the fabrication.

you need to protect the composite materials from uv light and water( swelling) .

since this is an automotive aplication scratch resistance would be nice since the sand and small stones will chip away paint on metal, not to mention what will it to to paint on composite.

tooling gelcoat would be welcome as a base to seal of the composite. since it is much harder.


dont worry about spending big bucks on mass production,

composite material fabrication is well know for being lots of manual labor, so by pulling a decent mold from this positive you could be making those hardtops in no time. just dont be cheap on the, tooling gelcoat, PVA & wax. this is a simple shape. just reinforce the mold with some wood beams and don't bash it around and you could be pulling doesns of hardtops from the same mold.

[RJS]

Hi Marko,

Sounds like you know your fiberglass. I have been learning from Tim (mb4tim from our site), and have got quite a few supplies from him and his suppliers.

I have made a few mistakes on this top, but they can all be fixed (I'm keeping this one for myself anyway). I will do a some things differently for any future tops.

For the top: 2 layers of 1.5 oz mat and then 2 layers of very heavy roving (biaxial weave w/ heavy mat - don't remember the weight off the top of my head). The top is over 1/4' think. Polyester resin. The mold is tooling gelcoat (orange) and the top is reg gelcoat. I know tooling gelcoat is stronger, but I understood it was a more brittle. I am using partall #2 wax and PVA for the releasing agents.

I will look into the kevlar. Don't know much about it at this point.

I did a lip that goes inside the top to follow the windshield (required a 2 pc mold). The lip then follows around the door windows. I have been considering a metal strip to go inside the lip for strength. Weather stripping will go along the whole lip to hopefully get a good quiet seal. I am using stock TR7 clamps (ebay) for the front (fiberglassed in metal strip at the clamp screws to make stronger), and will use a turnbuckle for the back to tie in the same place as the convertable top (same as other tops I have seen). I have seen fancier clamps for the back, but I will worry about fancy items after I have all the other issues worked out.

I am using polycarbonate for the back window (very strong and flexible enough to follow the curve of the back). It is the same stuff the Tim uses for wind deflectors. I originally bought a TR7 back window and thought I would use those, but the shape was not quite right, so I went in another direction (anyone want to buy a FHC back window?).

Rob