The "Housewitzser LST2" is born...

[nativepaul]

I use an angle grinder too, but a big 9.5" one, with a stone cutting diamond disc about 6" dia, The cuts are not the thinnest so there is a lot of dust and it is best done outdoors with mask and gloves at least, but an 18" cut takes just a few seconds, and the cuts are straight as an arrow and with no tearing like a hacksaw can leave or jagies like a dremel can leave, and require no further sanding to finish unless you want to bevel the edges.

Once the cuts are made and beveled/cleaned up if needed sealing the cut edges of the CF with thin Cyno to help prevent de-lamination.