The main spar is 1 strip 25mm UD carbon two-third span and a small piece 100mm long
Then we put in 1 layer of 25 grams glass - we have made it both straight and 45 degrees - and we can't figure out if it gives any advantage. Therefore I lay it 45 degrees at the moment; since that’s the way my roll is cut.

Then another piece of kevlar and a piece of carbon tape half the V-tail length.

Now comes the vacuum (with tear cloth and everything).

 This way my rudder consist of 93 grams carbon and 75 grams glass - all at 45 degrees - its stiff!  

These pictures do thoug show a V-tail made intirely of glass

 Putting the parts together:

I use plastic straws with carbon sock/epoxy as webbing in front of and behind the hinge line – 20 mm apart

In the centre I either make a V in a separate mould (cross: 3,5x3,5mm) or make one wet ”V” while working. The wet ”V” consist of about 1 meter of carbon wetted tow that makes a loop – 50-60mm long when flat. This wetted flattened loop I put into a piece of carbon sock. You may have to cut the sock at the bottom of the V to make sure that it doesn’t go flat. This wet V, I put into the mould when closing it.

   
 The lightest V-tail I have build weighed just under 80 grams, and I normally build them at about 83 - 90 grams.

 I don’t measure the amount of epoxy as accurate when I make V-tails, as when I make wings. Have a Scottish attitude – be modest about the epoxy amount.