We have a tapered Proctor mast. We use a powerful kicker and backstay.
The problem is that the rivets connecting the mast to the foot casting shear ( over the season) starting at the front of the mast and working back. At the moment the front one is missing and the next two (total 5 rivets in the mast) are loose.
We thought this may have been caused by excessive kicker and have moved the attachment point hard against the actual base of the mast, this has not solved the problem.
Has anyone had a similar problem?. Any thoughts on the cause?
We had the same problem. Since much of the forces acting on the mast are downwards, the problem is not too serious but will worsen and should be rectified. We decided the cause was the rocking of the mast on its foot caused by it being allowed to pivot forwards off wind and then pulled back upwind by mainsheet/backstay tension. Kicker tension will contribute if the tackle is mounted on the mast step so the thrust of the boom drives the foot forward. Ideally the kicker tackle should be mounted low down on the mast. Depending on how loose the rivets have become, simply drill them out and replace. Don’t use stainless screws as replacements, these will corrode the mast and enlarge the holes further. If necessary, redrill the mast and step and re-rivet.
Yes we moved the kicker attatchment to the bottom of the mast and re rivited. This decreased the problem but it is now back again after the season. There must be a fundamental reason for the problem. If the backstay is released when running down wind the forward rivet would be in compression, this is the one that always goes first.