I like Slieve's idea. I would also point out that if you have cut the bevel but haven't tapered the other side, you have the option of turning the staves "upside down." when you re-fit things.

It sounds like your current angle makes a circle with 6 staves instead of the intended 8. Upside down (inside out?) would make a circle with more than 8 staves (12? I'll let you figure out the geometry instead of guessing here)

That could be a better starting point for re-cutting it into an 9 or 10 stave mast like Slieve suggested.

If I understand the problem correctly you have 8 staves with the wrong angle birdsmouth? If this is the case I would glue strips the required thickness to the back (opposite side to birdsmouth) of the stave. Then recut the birdsmouth to the correct 45 degrees.
Gary

Karlis

I would say that if you add laminate to the exterior of wooden mast to add stiffness, in order to get an effective result you would need to add it to the inside to (not feasible!!!)  you would effectively being turning the wood into a core..... think foam sandwich/nomex/balsa etc. You need to balance the laminate.  However you could try adding a balanced laminate to the exterior only..... something like  1 layer 600 biax / uni's /  1 layer 600 biax then use fairing comound to the achieve the required diameter..... I am not engineer and would not suggest you use the figures i have given..... these are just an example!!!  But I think this is not really a satisfactory soultion.

Kurt has given you a good suggestion......... bond anonther layer of the same wood onto the exsisting structure and then reduce it to the correct diameter........  but the best solution, for complete peace of mind, without consulting a qualified engineer is to start again, as David suggested.  Perhaps you can sell the first mast to recover some costs.

Peter

 

 

I don't like the idea of using FG to stiffen wood much. It can protect the surface effectively (if you can keep it from delaminating), but that is about it.

If you add more FG to an existing FG structure, it becomes larger, stronger, and stiffer, because it is (effectively) a larger single structure.

If you add FG to wood, they are different enough that they won't become a uniform composite object. Consider the problems that many people have found when they sheathed a wooden hull with FG.

If you add enough FG to make the FG alone strong and stiff enough for the job, the weight of the wood inside is wasted.

                                                                     Stavanger, Saturday

Karlis

When Hasler and McLeod wrote what they did about glass sheathing of wooden masts, I guess they had ordinary chopped mat or roving in mind. The problem with that is that it is much more elastic than wood. Therefore the wooden mast may be stressed (bent) to the limits without getting much support from the sheathing.

If the mast or roving is replaced with e-glass or s-glass with the most of the fibre orientation along the mast (unidirectional) and not woven, the sheathing will be much stiffer and probably add more support to the wooden mast. On the other hand we don’t want a sheathing material (carbon?) that is so stiff that it takes all the bending stress before the wood takes any load. That could mean ripping the sheathing first and then breaking the mast when the support from the sheathing has failed. My armchair guess is that a quite thick (5mm?) sheathing of unidirectional e-glass or s-glass would give a useful support. I may be wrong of course.

Arne