I've got a 100x100 gatepost that holds an 800x1800mm gate (all wood), the screws from the upper hinge have split the post, water has got in & the top 100mm or so of the post is rotten in the centre, where two of the hinge screws are fitted.. I can't replace the post at the moment & wonder what sort of repairs are possible. It looks like a metal post extender could be used to replace the upper part of the post, but this would involve removing stringers & slats which I would prefer not to do. Would clearing out the rot in the centre of the post & then filling the whole lot up with polyester resin be worthwhile or a waste of time? Thanks.