Fender vents - how to make a mould for fiberglass?
 

Hi guys,
I'm not Miata owner, however I really like local discussion about aero upgrades.
My goal is to make a fiberglass fender vents for RX-8 (not complete fender, just a small panel with vents to be bolted on original fender). Problem is that the fender is curved in both directions and I don't know how to make (which material) individual vents, so I can make a mould.
So far I tried wooden bar (not bendable to match curvature) and aluminium sheet (not stiff enough for mould). See the pictures and video.

Any ideas how to make individual vents (on original fender), so I can make a mould from it?

<iframe width="560" height="315" src="https://www.youtube.com/embed/krEhfpMHY1Y" frameborder="0" allowfullscreen></iframe>

https://www.miataturbo.net/attachmen...ine=1439746723
https://www.miataturbo.net/attachmen...ine=1439746723

THE GOAL!
https://www.miataturbo.net/attachmen...ine=1439746723

Whenever I'm fabricating something I use cardstock to make my templates first. It's easy to work with, cheap, and sturdy.
Cut a strip longer than you anticipate it being (account for the end folds too), then, with scissors, start trimming it until it fits like you want it to. Make all your vents. Make a suitable platform for them to rest on that will hold them in the right shape (still out of that cardstock), use spray adhesive and aluminum foil to cover the vents. Apply release compound to the mold, then begin applying your fibreglass. This can either be the final product, or the mold you make your real vents out of.

Like what this guy did, but the forums died out and no one updates it anymore

https://www.miataturbo.net/attachmen...ine=1439764880

https://www.miataturbo.net/attachmen...ine=1439764880

https://www.miataturbo.net/attachmen...ine=1439764880

Im going to work on my fender vents with aluminium, even tho I work on fiberglass on a daily basis at work.

https://www.miataturbo.net/attachmen...ine=1439764880

https://www.miataturbo.net/attachmen...ine=1439764880