Since the F-16 forum was so quiet now, I tought I would seize the opportunity and ask a question.

Mast building is a complicated matter. The building process does not allow faults in your laminating technique, you must have the engineering spot on or it will be too stiff or too flexible (that is fixable tough?), small errors in building or engineering will make your mast come down/break, the end result will be heavier than a bought mast etc. If you goof up on the building, you have wasted a lot of money on materials (I dont put a value on my time when doing stuff I enjoy).

Now, if one still wants to build a mast at home..
Reasons to do so could be several, e.g. one can not buy the spesific wing-profile you want for a reasonable sum, you need a beefier mast, you want to try it etc.

Professional masts are made by laminating a hollow profile in a female mould or a male mandrel. For an amateur one-off project the male mandrel is probably off limits (how do you get it off the mandrel, and building the mandrel would be time consuming), as is the seamless female mould technique. Building two halves in a female mould could be done. Building two female moulds, on for the front section and one for the aft sectin could also be done. Both methods lead to a complicated joining session.

I was wondering if somebody had tought about building a composite mast with foam as distance material. The ORMA60's have used (still do?) this method, and it leads to stiff and light masts. You need to take care with the compression and shear loads tough. Building a female mould and working with foam this way should be possible, but it still leaves the two halves to be joined and a sailtrack to be attached. Building the mast flexible enough and still durable might be an challenge.
Simpler still, would be a carbon tube, H, I or U beam bought from a pulltrusion company like the one virtually in my backyard http://www.vello.no/. Adding a foam fairing and a sailtrack to the fairing should not be too hard.

Question is, what would probably give the best result with regards to weight, durability, bending properties and ease of building of the above methods? Are there other methods?