carbon fibre to replace wood stringer

hi want to use  a 30mm wide carbon fibre  tape on a stringerless blank ,finished board lenth 6 foot 10 in, want to run it on top and bottom down the centre using polyester resin i will after shapping make a channel to lay it in flat so the top of tape is level to foam , depending on thckness of tape  then glass it in, then glass over top with 4 oze, can i be conferdent its not going to snap with my first wave.

Hello friend,

I know it may not have been what you want to hear, but your question was already answered in the general discussion.  Everyone who responded to your question is either a professional board-builder, extremely experienced hobbyist, or an engineer.  Lemat is all of the above.  Carbon fiber can be useful in some select applications on a surfboard, but what you are proposing is not sound structurally. 

I kindly recommend you do a bit of homework on how to manage the forces of tension and compression in a sandwich structure (which a foam cored surfboard is).

You would also save yourself quite a bit of time and money by learning about the physical properties of polyester resin versus epoxy resin, as well as the different fibers used in composites.

If you can get it, I highly recommend the book “Understanding Aircraft Composite Construction” by Zeke Smith. 

Take care.