Mast alignment in mast partner

[CAM]

The two important points when initially setting up a mast are the top and the bottom. You can't move the bottom side-to-side (generally), and you want the top centered. You want the rake where the designer intended, or somewhere different if you are curing a balance problem. Very few partners will be centered on the mast in either direction on a production glass boat, just don't worry about that. Most glass boats will have some taper at the partners (called "release" in mold making). Spartite is used all the time by folks that frequently step and unstep their masts.