Hi,

Do you think it is possible to sharpen a carbon composite blade?
I would like to try to make a straight razor blade or a kamisori blade but is it possible
to sharpen the edge like a ceramic blade?
If yes what composite is the best performer for this application?
Carbon, Kevlar, twaron?
Gelcoat or just resin?

Thanks for your help guys.
Kind Regards,
Olivier

It would also likely be worth doing a full post-cure on whatever resin system you choose as that will increase stability and also make the resin slightly harder.  Also means if you work the blade a bit too much while shaping, the heat generated will be less likely to ruin the edge.

Also for those of you in the UK, you would be wise to read up on the specifics of knife law surrounding non-metal blades as during 2004 the Criminal Justice Act 1988 was modified to include "stealth knives" in section 141.  They have described a "stealth knife as:
 

"a stealth knife, that is a knife or spike, which has a blade, or sharp point, made from a material that is not readily detectable by apparatus used for detecting metal and which is not designed for domestic use or for use in the processing, preparation or consumption of food or as a toy"

  I have heard of some people adding metal strips inside the lay up but I am not sure if this is 100% compliant with the law, although it does seem that logically it would be fine. So if you are making anything, make sure you are complying with the law.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant