External to Internal halyards modification

[Shelter]

Hello all,
I'm new to the forum so be gentle. I'm a proud owner of a Southern Cross 39 and facing a general refit, on most systems, over the next two years, so you will be hearing from me again. The rigging is one of the projects and have several questions regarding an idea, would like to hear any thoughts, experiences and tips you all might have.
As of now, there are two halyards, running externally, to the mast. I wish to convert one halyard to two separate ones running inside the mast. In addition, I want to add a winch, cleats and locks to the mast for the foresails halyards and such. My questions are such:

1) Has anyone with a SC39, or a similar boat, done this and can contribute any knowledge on this?

2) What are the considerations of adding hardware on to the mast when it comes to weakening of it?

So far have enjoyed reading threads,
Hope to continue.

[GordMay]

Greetings and welcome aboard the CF, Shelter.

[Orion Jim]

Seems intimidating at first but pretty simple. Cut a slot, file smooth, mount an exit plate. Done!
You can rivet or thread and screw. Both are fine. Spar is not weakened, may be stronger!

[Cheechako]

No real problem adding widgets to a good mast.

[roverhi]

Going internal also frees up a set of sheaves for a spare halyard that can be used for either the main or jib should the need arise.

Only difficult thing about going internal is keeping them separate while threading them into the mast. Easiest if done on the ground. Thread one in and use a winch to cinch it up tight. Roll the mast over and thread the other one. Fist halyard should be out of the way if you got it tight enough

[Shelter]

Thanks for the reply guys, I'll go ahead, will keep you posted.
Cheers