Again; nice writup Giulietta. I was wondering about the difference between rake and pre-bend. When you measure pre-bend is that in addition to the rake? So first you measure the rake and then you put additional pre-bend on the mast?
I also have a question regarding the wedging at the cabin roof for a keel stepped mast. "Spartite" was installed at the partners so I can't remove and replace wedges. Can I add rake and bend with the Spartite in place or would trying to rake the mast at this point only result in bending? The mast already has a factory taper and pre-bend IIRC; it's a tall rig, the I is 52'. Visually I don't see much rake; but there is bend above the upper spreaders.
KH..the bend is mesasured by bringing the halyard you used to set the rake to near the mast foot, so you can measure it, by measuring the distance between the halyard and the mast, and this is obviously independent of the rake, since the halyard starts at the mast head and comes to the mast foot, and that happens even if the mast is lying down on the floor.
technically, the bend should be there independent of the rake, that is why you set the rake first and the bend after. Now the bend can be increased at a later stage by the backstay, if you have one.
As far as the mast thru deck seal..obviously it would be better if it was not there, as the thru deck is creating a "pivoting point" in the mast, thus affecting the ability to properly set rake and bend.
But if you can't remove it, "he that doesn't have a dog, can hunt with a cat", as we say in my country.
The rake can to some extent still be set but I doubt you can get better than 3 deg rake, as it will start bending, yes.. Give it a try..
If you knew how many people I know that complain about boats with excessive or lack of weatherhelm that are sailing boats with wrong rake, you would be surprized....
The tapper is to reduce weight aloft, make the top more flexible and make the mast loom good, and less "tree stump" on the top... the bend is done once on the boat, not at the factory..they ship them straight as a whistle..