Hi!
My customer wants to replace his sliding sunroof with cf flat sheet. He wants it to be quiet stiff but light. I have 3mm soric-like core material, 220gsm cf, 200gsm diolen, wide variety of woven glass clothes and some uni-dir cf 200g 5cm wide cf tape. I could use poly resin as it is uv stable, but I have epoxy also. It will be mounted with rivets to the roof. These are the dimensions : 40cmx80cm or 16inx32 in. How do you suggest to make my layup? I thought about poly resin and carbon/diolen/about 300gsm glass/core/300gsm glass/ cf or diolen. It is for racing purpose.I will laminate it on piece of glass. Please share your suggestions and experience. Thanks for taking your time reading that!
Bye
Wojtek from Poland

~~~Everytime I hear sound of demoulding part I have eargasm~~~

What process are you planning on using wet-lay, wet-lay and vac bag, infusion?

Warren

Carbon Copies Ltd

Oh yeah In forgot,  I use vacuum bagging, 

~~~Everytime I hear sound of demoulding part I have eargasm~~~

Ok. most car roofs are not flat anyway so once the panel is riveted/bonded into place it will follow the curves of the roof anyway which will add stiffness so a 1mm CF sheet would probably be ok for the size you mention.
If you want to make it really stiff and light I would use 2x200grm - 3mm Soric - 1 450grm or 2x200grm. If you cut the soric 20mm smaller than the roof opening when you vac bag, it will pull the CF around the Soric leaving a 1mm ish thick flange around the Soric but the centre section 4mm ish thick. That way if you trim the part to leave a 25mm flange all the way round the panel will sit almost flush with the surrounding roof. One thing to remember if you use this method you will get a "shadow" of the edge of the Soric showing on the seen surface. If it is for motorsport a perfect cosmetic finish probably isn't necessary.
I will try and post some pictures later that may make things easier to understand.

Warren

Carbon Copies Ltd

If you squish the edge of the soric or trim it with a razor blade at an angle you minimise the shadow on the edge. Alternatively a couple of layers of carbon tape will help too.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

Customer wants to have only one side, that looks great so I will cut 20 mm less soric,  and I will place carbon tape mixed with diolen. And I will use only 220gsm/soric/220gsm cf

~~~Everytime I hear sound of demoulding part I have eargasm~~~

Found some pictures that may make things a little clearer.

This is done with Infusion but vac bagging should work ok. You can make out the shadow of the Soric in the shape of a "T" on the Dashboard.
If you round off the corners of the Soric the cloth will conform around it without any creases.
If you use Closed Cell Foam as the core and chamfer the edges with sandpaper you don't get the shadow.

Warren

Carbon Copies Ltd