Has anyone built themselves a GRP hardtop?

[Mitchelkitman]

As title.... I intend to build a GRP hardtop for a roadster, with the shape similar to a soft top. Intention being to use it in the Winter. Wanting to keep the weight as low as possible, and a good enough finish to paint (probably matt black paint).

[kon]

"a roadster"... as in, a z3? If so, should be able to buy all the clips and fixings for the hard top which they made for the car. Shouldnt be too hard to make a thin metal frame which connects all the bits, and then cardboard, parcel tape and grp to connect them. Same with an MX5, and with the price of those hard tops, I wouldnt be surprised if someone has done that a few times already.
I wondered if something like the lightyear fastback top might be a good starting point, if you can find one (or something like it) on this side of the world (light-year are aussie-based).
https://www.miataturbo.net/build-thr...-48089/page28/

[Mitchelkitman]

Oops... sorry for causing confusion. It's a Calvy Mitchel (hence my user name). - old style roadster. Nearest equivalent is an NG kit car.

[Lucky@LeMans]

I've seen it done using a timber frame and 1/4" plywood clad with black vinyl. You could glass over the wood and then paint it, depends on what finish you want.

[Mitchelkitman]

Thanks for your comments lucky. With your experience of GRP, do you consider a horizontal flat panel of the roof with a total of 1200 gsm chopped strand mat would sag over time? If so, maybe adding 5mm nidaplast honeycomb reinforcement and 450 mm layer under may stop it sagging? roughly 1m x 0.8m panel? I'll be grateful for your opinion.

[Lucky@LeMans]

I'm no GRP expert, best to talk to a laminator for their opinion.

[IanA]

The Tribute guys could probably take a splash mould of the existing hood and then lay up a basic shape for you. Reinforce it with f/g rope as required.

[Munky]

You could always try a conventional Carson top style, using electrical conduit and chicken wire but…
A grp version of a Carson top is covered in detail here:
https://www.jalopyjournal.com/forum/...on-top.240611/

I’ve had the thought of using the existing hood, wrapped in cling film and tinfoil, to create an original mold. Then make a more structured part from that.

Please post if you do move forward with this!

[Mitchelkitman]

Thanks for that. I planned to use foam board, but now have a fiendish plan to save effort (because I'm lazy). I'll report back with my result (should be by Summer)

[froggyman]

I once saw a JC Midge with a hard top that looked just like a soft top. It was only when the owner tapped on it that you knew it was fibreglass and not canvas. Good luck.

[Lucky@LeMans]

Have you managed to make any progress so far ?

[Mitchelkitman]

Pots of resin etc arriving tomorrow - I'll start when the weather gets warmer.

[redratbike]

did you go for it ?

[Mitchelkitman]

I've not had time yet = too busy restoring a mates 60 year old caravan

[redratbike]

Originally Posted by Mitchelkitman

I've not had time yet = too busy restoring a mates 60 year old caravan

i know how that feels i have been meaning to mould some headlight covers since xmas and just haven