aluminium mast extension

i have just got a 500mm section of z spars mast so as i can extend my existing mast to allow a tubular bimini to be fitted below the boom . there is insufficient room at present . i intend to fit it to the top as the boat is fractional rig and it means i need not extend all the standing rigging as the only load at the top is the main / headboard and the cruising chute / spinnaker sheave . my question is ... how far down inside the existing mast do i need to fix the re inforcing straps and how many fixings ? the new section will butt up to the old section . i thought z spars did a sleeve for this job , but they dont ! has anyone had experience of this type of job ?

Hi Gramos, welcome to the forum, I hope you will enjoy it here


I (unfortunately) have no experience with this, but I would insert it as far as possible inside the existing mast so as to receive the maximum stability.