It's just the one I need and it'd need to be in high temp resin.  I think the tube / prachment / sleeve is the way forwards.

For straight tubing solarcomposites sells inexpensive sleeves and silicone coated heat shrink tubing. Then you just need a section of tubing with and outer diameter matching your desired inner diameter. I used 1 layer of parchment paper as a release material and the carbon tube slid right off.

80mm is 3", but this is how I built my 4" pipe:

I'm suddenly interesting in how tubes are made.  If I needed to make a tube with an accurate 80mm ID how would I go about it?  Its all fairly new to me so please type slowly and with small words!  The tube needs to bear around 1-1.5 bar of pressure so in my head I was considering an 80mm wax cylinder and roll wrapping some UD around it then putting some braided sleeve over the top and bagging the whole lot.  Its the only way I could tink to do it.

Tube would form the outer case for a wren jet turbine.